Editing Cartridge (firearms)

{{Short description|Pre-assembled firearm ammunition}}
{{Use dmy dates|date=June 2021}}

[[File:Cartridge cross section.svg|thumb|A modern round consists of the following:<br />''1.'' ''Bullet'', as the [[projectile]]; <br />''2.'' ''Cartridge case'', which holds all parts together; <br />''3.'' ''[[Propellant]]'', for example, [[gunpowder]] or [[cordite]];<br />''4.'' ''Rim'', which provides the extractor on the firearm a place to grip the casing to remove it from the chamber once fired; <br />''5.'' [[Centerfire ammunition#Centerfire primers|''Primer'']], which ignites the propellant]]

A '''cartridge''',<ref>{{cite web |url=https://saami.org/saami-glossary/?letter=C |title=Glossary – SAAMI |publisher=[[Sporting Arms and Ammunition Manufacturers' Institute]] |archiveurl=https://web.archive.org/web/20200804173256/https://saami.org/saami-glossary/?letter=C |archivedate=4 August 2020 |accessdate=2 April 2021 |quote=CARTRIDGE: A single round of ammunition consisting of the case, primer and propellant with or without one or more projectiles. Also applies to a shotshell. }}</ref><ref>{{cite web |url=https://www.cip-bobp.org/homologation/uploads/ciptexts/definition-calibrage-en.pdf |title=DEFINITIONS OF C.I.P. TERMS |publisher=[[Commission internationale permanente pour l'épreuve des armes à feu portatives]] |date=2001 |accessdate=2 April 2021 |quote=Cartridge – Cartouche: A means to fire a propellant charge by means of a percussion device, with or without a projectile, all contained in a case. |archive-date=29 June 2021 |archive-url=https://web.archive.org/web/20210629122420/https://www.cip-bobp.org/homologation/uploads/ciptexts/definition-calibrage-en.pdf |url-status=live }}</ref> also known as a '''round''', is a type of pre-assembled firearm ammunition packaging a [[projectile]] ([[bullet]], [[shot (pellet)|shot]], or [[shotgun slug|slug]]), a [[propellant]] substance ([[smokeless powder]], [[black powder substitute]], or [[black powder]]) and an ignition device ([[primer (firearm)|primer]]) within a [[metallic cartridge|metallic]], [[paper cartridge|paper]], or [[polymer-cased ammunition|plastic case]] that is precisely made to fit within the [[gun barrel|barrel]] [[chamber (firearms)|chamber]] of a [[breechloading]] gun, for convenient transportation and handling during shooting.<ref>{{Cite book|author=Sparano, Vin T.|chapter=Cartridges|title=The Complete Outdoors Encyclopedia|publisher=Macmillan|year=2000|isbn=978-0-312-26722-3|page=37|chapter-url=https://books.google.com/books?id=iTX3BYBnOTcC&pg=PA37}}</ref> Although in popular usage the term "bullet" is often used to refer to a complete cartridge, the correct usage only refers to the projectile.

Military and commercial producers continue to pursue the goal of [[caseless ammunition]]. Some [[artillery]] ammunition uses the same cartridge concept as found in [[small arms]]. In other cases, the [[shell (projectile)|artillery shell]] is separate from the propellant charge.

A cartridge without a projectile is called a ''[[blank (cartridge)|blank]]''; one that is completely [[inert munitions|inert]] (contains no active primer and no propellant) is called a ''[[dummy round|dummy]]''; one that failed to ignite and shoot off the projectile is called a ''[[dud]]''; and one that ignited but failed to sufficiently push the projectile out of the barrel is called a ''[[squib load|squib]]''.

[[File:Cartridge Sample 2.jpg|right|thumb|upright=2|A variety of rifle cartridges: ('''1''')[[.17 HM2]] ('''2''')[[.17 HMR]] ('''3''')[[.22LR]] ('''4''')[[.22 Winchester Magnum Rimfire|.22 Win Mag R/F.22 WMR]] ('''5''')[[.17/23 SMc]] ('''6''')[[5mm/35 SMc]] ('''7''')[[.22 Hornet]] ('''8''')[[.223 Remington]] ('''9''')[[.223 WSSM]] ('''10''')[[.243 Win]] ('''11''')[[P.O. Ackley#Wildcats and Ackley Improved Cartridges|.243 Win Improved (Ackley)]] ('''12''')[[.25-06 Remington]] ('''13''')[[.270 Winchester]] ('''14''')[[.308 Winchester]] ('''15''')[[.30-06 Springfield]] ('''16''')[[.45-70|.45-70 Government]] ('''17''')[[.50-90 Sharps]]]]
[[File:Big caliber cartridge comparison withDATA.jpg|thumb|upright=2]]

==Type==
Cartridges can be categorized by the type of primer, which can be accomplished by igniting a small charge of an [[shock sensitivity|impact]]-sensitive explosive compound  is located 
*At the center of the [[#Case|case head]] ([[centerfire]])
*Inside the [[rim (firearms)|rim]] ([[rimfire ammunition|rimfire]])
*Inside the walls on the fold of the case base that is shaped like a cup (cupfire)
*In a sideways projection that is shaped like a pin ([[pinfire]])
*a lip (lipfire); or in a small bulge shaped like a nipple at the case base ([[Teat-fire cartridge|teatfire]]), 

or by an [[electronic firing|electric-sensitive]] chemical mixture.

Only small-caliber rimfire cartridges and centerfire cartridges have survived into the modern day.

==Design==
===Purpose===
The cartridge was invented specifically for [[breechloading]] firearms. Prior to its invention, the projectiles and propellant were carried separately and had to be individually loaded [[muzzleloading|via the muzzle]] into the [[gun barrel]] before firing, then have a separate [[fire making|ignitor]] compound (from a burning [[slow match]], to a small charge of [[gunpowder]] in a [[flash pan]], to a metallic [[percussion cap]] mounted on top of a "nipple" or cone), to serve as a source of [[activation energy]] to set off the shot. Such loading procedures often require adding paper/cloth [[wadding]] and [[ramrod|ramming down repeatedly with a rod]] to optimize the [[seal (mechanical)|gas seal]], and are thus clumsy and inconvenient, severely restricting the practical [[rate of fire]] of the weapon, leaving the shooter vulnerable to the threat of [[close combat]] (particularly [[cavalry]] [[charge (warfare)|charge]]s) as well as complicating the logistics of ammunition.

The primary purpose of using a cartridge is to offer a handy pre-assembled "all-in-one" package that is convenient to handle and transport, easily loaded into the breech (rear end) of the barrel, as well as preventing potential propellant loss, contamination or degradation from [[moisture]] and the elements. In modern [[repeating firearm#Autoloading|self-loading firearm]]s, the cartridge case also enables the [[action (firearms)|action]] mechanism to use part of the [[propellant]]'s energy (carried inside the cartridge itself) and cyclically load new rounds of ammunition to allow quick repeated firing.

To perform a firing, the round is first inserted into a "ready" position within the [[chamber (firearms)|chamber]] aligned with the [[bore axis]] (i.e. "in ''battery''"). While in the chamber, the cartridge case [[obturation|obturate]]s all other directions except the [[gun barrel#Bore|bore]] to the front, reinforced by a [[breechblock]] or a locked [[bolt (firearms)|bolt]] from behind, designating the forward direction as the [[path of least resistance]]. When the [[trigger (firearms)|trigger]] is pulled, the [[sear (firearm)|sear]] disengages and releases the [[hammer (firearms)|hammer]]/[[firing pin|striker]], causing the [[firing pin]] to impact the [[primer (firearms)|primer]] embedded in the base of the cartridge. The [[shock sensitivity|shock-sensitive]] chemical in the primer then creates a [[jet (fluid)|jet]] of [[spark (fire)|spark]]s that travels into the case and ignites the main propellant charge within, causing the powders to ''[[deflagration|deflagrate]]'' (but not ''[[detonation|detonate]]''). This rapid [[exothermic]] [[combustion]] [[yield (chemistry)|yield]]s a mixture of highly energetic gases and generates a very high [[pressure]] inside the case, often [[fire forming|fire-forming]] it against the chamber wall. When the pressure builds up sufficiently to overcome the fastening [[friction]] between the projectile (e.g. bullet) and the case neck, the projectile will detach from the case and, pushed by the expanding high-pressure gases behind it, [[internal ballistics|move down the bore]] and out the [[muzzle (firearms)|muzzle]] at [[muzzle velocity|extremely high speed]]. After the bullet exits the barrel, the gases are released to the surroundings as [[ejecta]]e in a [[muzzle blast|loud blast]], and the chamber pressure drops back down to [[ambient pressure|ambient level]]. The case, which had been elastically expanded by high pressure, contracts slightly, which eases its removal from the chamber when pulled by the [[extractor (firearms)|extractor]]. The spent cartridge, with its projectile and propellant gone but the case still containing a used-up primer, then gets ejected from the gun to clear room for a subsequent new round.

=== Components ===
A modern cartridge consists of four main components: the ''case'', the ''projectile'', the ''propellant'', and the ''primer''.

==== Case ====
[[Image:Many bullets.jpg|thumb|Three non-bottlenecked cartridges ([[9×19mm Parabellum]], [[.40 S&W]] and [[.45 ACP]]) on the left, three bottlenecked cartridges ([[FN 5.7×28mm]], [[5.56×45mm NATO]] and [[.300 Winchester Magnum]]) in the center, and two [[polymer-cased ammunition|polymer-cased]] [[12-gauge]] [[shotshell]]s on the right]]
The main defining component of the cartridge is the case, which gives the cartridge its shape and serves as the integrating [[housing (engineering)|housing]] for other functional components, it acts as a container for the propellant powders and also serves as a protective [[shell (structure)|shell]] against the elements; it attaches the projectile either at the front end of the cartridge ([[bullet]]s for [[pistol]]s, [[submachine gun]]s, [[rifle]]s, and [[machine gun]]s) or inside of the cartridge ([[wadding]]/[[sabot (firearms)|sabot]] containing either a quantity of [[shot (pellet)|shot (pellets)]] or an individual [[shotgun slug|slug]] for [[shotgun]]s), and align it with the [[gun barrel#Bore|barrel bore]] to the front; it holds the [[primer (firearms)|primer]] at the back end, which receives an impact from a [[firing pin]] and is responsible for igniting the main propellant charge inside the case.

While historically [[cartridge paper|paper]] had been used in the [[paper cartridge|earliest cartridges]], almost all modern cartridges use [[metallic cartridge|metallic casing]]. The modern metallic case can either be a "bottleneck" one, whose frontal portion near the end opening (known as the "case ''neck''") has a noticeably smaller [[diameter]] than the main part of the case ("case ''body''"), with a noticeably angled slope ("case ''shoulder''") in between; or a "straight-walled" one, where there is no narrowed neck and the whole case looks [[cylindrical]]. The case shape is meant to match exactly to the [[chamber (firearms)|chamber]] of the gun that fires it, and the "neck", "shoulder", and "body" of a bottleneck cartridge have corresponding counterparts in the chamber known as the "chamber neck", "chamber shoulder", and "chamber body". 

Some cartridges, like the [[.470 Capstick]], have what is known as a "ghost shoulder" which has a very slightly protruding shoulder, and can be viewed as a something between a bottleneck and straight-walled case. A ghost shoulder, rather than a continuous taper on the case wall, helps the cartridge to line up concentrically with the bore axis, contributing to accuracy. The front opening of the case neck, which receives and fastens the bullet via [[crimp (joining)|crimping]], is known as the ''{{vanchor|case mouth}}''. The closed-off rear end of the case body, which holds the [[primer (firearms)|primer]] and technically is the case ''base'', is called the ''case head'' as it is the most prominent and frequently the widest part of the case. There is a circumferential [[flange]] at the case head called a ''[[rim (firearms)|rim]]'', which provides a lip for the [[extractor (firearms)|extractor]] to engage. Depending on whether and how the rim protrudes beyond the maximum case body diameter, the case can be classified as either "rimmed", "semi-rimmed", "rimless", "rebated", or "belted".

The shape of a bottleneck cartridge case (e.g. body diameter, shoulder slant angle and position, and neck length) also affects the amount of attainable pressure inside the case, which in turn influences the [[accelerative]] capacity of the projectile. [[Wildcat cartridge]]s are often made by reshaping the case of an existing cartridge. Straight-sided cartridges are less prone to rupturing than [[Tapering (firearms)|tapered cartridges]], in particular with higher pressure propellant when used in blowback-operated firearms.

In addition to case shape, [[rifle cartridge]]s can also be grouped according to the case dimensions of a cartridge, this is usually referring to the cartridge's overall length (COL), which in turn dictates the minimal [[receiver (firearms)|receiver]] size and operating space ([[bolt (firearms)|bolt]] travel) needed by the [[action (firearms)|action]], into either "mini-action", "short-action", "long-action" ("standard-action"), or "[[magnum cartridge|magnum]]-action" categories.
* ''Mini-action'' cartridges are usually [[intermediate cartridge|intermediate rifle cartridges]] with a COL of {{cvt|2.25|in|lk=on|order=flip}} or shorter in length, which is most commonly exemplified by the [[.223 Remington]];
* ''Short-action'' cartridges are usually [[fully powered cartridge|full-powered rifle cartridge]]s with a COL between {{cvt|2.25|and|2.8|in|order=flip}}, which is most commonly exemplified by the [[.308 Winchester]];
* ''Long-action'' ("standard-action") cartridges are usually traditional full-powered rifle cartridges with a COL between {{cvt|2.8|and|3.34|in|order=flip}}, which is most commonly exemplified by the [[.30-06 Springfield]];
* ''Magnum-action'' cartridges are rifle cartridges that are both longer, wider and more powerful than traditional long-action rifle cartridges, with a COL between {{cvt|3.34|and|3.6|in|order=flip}}, including some of the long-action cartridges with a case head larger than {{cvt|.50|in|order=flip}} diameter, which is most commonly exemplified by the [[.375 Holland & Holland Magnum]].<ref>{{cite web|url=https://blog.gunassociation.org/short-action-vs-long-action-rifles/|title=Short Action vs Long Action Rifles Explained|last=|first=|date=3 August 2020|publisher=American Gun Association|access-date=1 February 2021|archive-date=18 January 2021|archive-url=https://web.archive.org/web/20210118134927/https://blog.gunassociation.org/short-action-vs-long-action-rifles/|url-status=live}}</ref>

The most popular material used to make cartridge cases is [[brass]] due to its good [[corrosion resistance]]. The head of a brass case can be work-hardened to withstand the high pressures, and allow for manipulation via extraction and ejection without rupturing. The neck and body portion of a brass case is easily annealed to make the case [[ductile]] enough to allow reshaping so that it can be [[handloading|handloaded]] many times, and [[fire forming]] can help [[accurize]] the shooting.

Steel casing is used in some [[plinking]] ammunition, as well as in some military training ammunition (mostly from the [[former Soviet republics]] of Armenia, Azerbaijan, Belarus, Estonia, Georgia, Kazakhstan, Kyrgyzstan, Latvia, Lithuania, Moldova, Russia, Tajikistan, Turkmenistan, Ukraine, and Uzbekistan), along with Russia and China.{{Citation needed|date=September 2018}} Steel is less expensive to make than brass, but it is far less corrosion-resistant and not feasible to reuse and reload.  Military forces typically consider [[Service rifle|service]] [[small arms]] cartridge cases to be disposable, single-use devices. However, the mass of the cartridges can affect how much ammunition a soldier can carry, so the lighter steel cases do have a [[Military logistics|logistic]] advantage.<ref>{{Cite web |title=Mass, Weight, Density or Specific Gravity of Different Metals |url=https://www.simetric.co.uk/si_metals.htm |access-date=2022-11-07 |website=www.simetric.co.uk |archive-date=31 December 2018 |archive-url=https://web.archive.org/web/20181231175853/https://www.simetric.co.uk/si_metals.htm |url-status=live }}</ref> Conversely, steel is more susceptible to contamination and damage so all such cases are varnished or otherwise sealed against the elements.  One downside caused by the increased strength of steel in the neck of these cases (compared to the annealed neck of a brass case) is that [[propellant]] gas can blow back past the neck and leak into the chamber. Constituents of these gases condense on the (relatively cold) chamber wall, and this solid propellant residue can make extraction of fired cases difficult.  This is less of a problem for small arms of the former [[Warsaw Pact]] nations, which were designed with much looser chamber [[engineering tolerance|tolerance]]s than [[NATO]] weapons.{{Citation needed|date=September 2018}}

Aluminum-cased cartridges are available commercially. These are generally not reloaded, as aluminum [[fatigue (material)|fatigue]]s easily during firing and resizing.  Some calibers also have non-standard primer sizes to discourage reloaders from attempting to reuse these cases.

{{missing information|semi-combustible cases in [[120×570mm NATO]] tank shells: the body is polymer, but the base stays|date=March 2023}}
[[Polymer-cased ammunition|Plastic cases]] are commonly used in [[shotgun shell]]s, and some manufacturers offer [[polymer]]-cased [[centerfire]] pistol and rifle cartridges.<ref>Johnson, S. (2013, January 10). Extreme polymer research’s polymer handgun cartridge cases -. The Firearm Blog. https://www.thefirearmblog.com/blog/2011/09/23/extreme-polymer-researchs-polymer-handgun-cartridge-cases/ {{Webarchive|url=https://web.archive.org/web/20240204035450/https://www.thefirearmblog.com/blog/2011/09/23/extreme-polymer-researchs-polymer-handgun-cartridge-cases/ |date=4 February 2024 }}</ref><ref>Beckstrand, T. (2018, October 16). True velocity’s new polymer-cased ammunition. Guns and Ammo. https://www.gunsandammo.com/editorial/true-velocitys-new-polymer-cased-ammunition/247607 {{Webarchive|url=https://web.archive.org/web/20240204035450/https://www.gunsandammo.com/editorial/true-velocitys-new-polymer-cased-ammunition/247607 |date=4 February 2024 }}</ref>

==== Projectile ====
{{main|Bullet|Shot (pellet)|Shotgun slug}}
As firearms are projectile weapons, the projectile is the effector component of the cartridge, and is actually responsible for reaching, impacting, and exerting damage onto a target. The word "projectile" is an [[umbrella term]] that describes any type of [[projectile|kinetic object]] launched into [[projectile motion|ballistic flight]], but due to the ubiquity of [[rifled]] firearms shooting bullets, the term has become somewhat a technical [[synonym]] for bullets among [[handloading|handloaders]].  The projectile's motion in flight is known as its [[external ballistics]], and its behavior upon impacting an object is known as its [[terminal ballistics]].

A bullet can be made of virtually anything (see [[#Projectile design types|below]]), but [[lead]] is the traditional material of choice because of its high density, [[malleability]], [[ductility]], and low [[cost of production]]. However, at speeds greater than {{cvt|300|m/s}}, pure lead will melt more and deposit [[fouling]] in rifled bores at an ever-increasing rate. [[Alloying]] the lead with a small percentage of [[tin]] or [[antimony]] can reduce such fouling, but grows less effective as velocities are increased. A cup made of harder metal (e.g. copper), called a ''gas check'', is often placed at the base of a lead bullet to decrease lead deposits by protecting the rear of the bullet against melting when fired at higher pressures, but this too does not work at higher velocities. A modern solution is to cover the bare lead in a protective [[powder coat]], as seen in some rimfire ammunitions. Another solution is to encase a lead core within a thin exterior layer of harder metal (e.g. [[gilding metal]], [[cupronickel]], [[copper alloys]] or steel), known as a ''[[jacketing]]''. In modern days, steel, [[bismuth]], [[tungsten]], and other exotic alloys are sometimes used to replace lead and prevent [[lead poisoning|release of toxicity]] into the environment. In [[armor-piercing bullet]]s, very hard and high-density materials such as [[hardened steel]], [[tungsten]], [[tungsten carbide]], or [[depleted uranium]] are used for the penetrator core.

[[Non-lethal weapon|Non-lethal]] projectiles with very limited [[penetration (weaponry)|penetrative]] and [[stopping power]]s are sometimes used in [[riot control]] or training situations, where killing or even wounding a target at all would be undesirable. Such projectiles are usually made from softer and lower-density materials, such as [[plastic bullet|plastic]] or [[rubber bullet|rubber]]. [[Wax bullet]]s (such as those used in [[Simunition]] training) are occasionally used for force-on-force [[tactical engagement simulation|tactical training]]s, and [[pistol dueling]] with wax bullets used to be a [[shooting sport|competitive]] [[Olympic sport]] prior to [[World War I]].

For [[smoothbore]] weapons such as shotguns, small metallic balls known as [[shot (pellet)|shot]]s are typically used, which is usually contained inside a semi-flexible, cup-like [[sabot (firearms)|sabot]] called "[[wadding]]". When fired, the wadding is launched from the gun as a payload-carrying projectile, loosens and opens itself up after exiting the barrel, and then [[inertia]]lly releases the contained shots as a hail of sub-projectiles. Shotgun shots are usually made from bare lead, though copper/[[zinc]]–[[total metal jacket|coated]] steel balls (such as those used by [[BB gun]]s) can also be used. Lead pollution of wetlands has led to the [[British Association for Shooting and Conservation|BASC]] and other organizations campaigning for the phasing out of traditional lead shot.<ref>{{cite web|title= Lead|url= https://basc.org.uk/lead/|website= www.basc.org.uk|accessdate= 18 April 2021|archive-date= 18 April 2021|archive-url= https://web.archive.org/web/20210418204107/https://basc.org.uk/lead/|url-status= live}}</ref> There are also unconventional projectile fillings such as bundled [[flechette#Shotguns|flechette]]s, [[riot gun#Rubber buckshot|rubber balls]], [[rock salt]] and [[magnesium]] shards, as well as [[non-lethal weapon|non-lethal]] [[shotgun#Specialty ammunition|specialty projectiles]] such as [[baton round|rubber slug]]s and [[bean bag round]]s. Solid projectiles (e.g. [[shotgun slug|slug]]s, [[baton round]]s, etc.) are also shot while contained within a wadding, as the wadding [[obturate]]s the bore better and typically [[sliding (motion)|slide]]s less frictionally within the barrel.

==== Propellant ====
{{Main|Firearm propellant}}
[[Image:Powder Samples.jpg|thumb|Smokeless powders used for [[handloading]]]]

When a propellant is ignited and begins to [[combustion|combust]], the resulting [[chemical reaction]] releases the [[chemical energy]] stored within. At the same time, a significant amount of gaseous [[product (chemistry)|product]]s are released, which are highly energetic due to the [[exothermic]] nature of the reaction. These combustion gases become highly pressurized in a confined space—such as the cartridge casing (reinforced by the [[chamber (firearms)|chamber]] wall) occluded from the front by the projectile (bullet, or [[wadding]] containing [[shot (pellet)|shot]]s/[[shotgun slug|slug]]) and from behind by the [[Primer (firearms)|primer]] (supported by the [[bolt (firearms)|bolt]]/[[breechblock]]). When the pressure builds up high enough to overcome the [[crimp (joining)|crimp]] friction between the projectile and the case, the projectile separates from the case and gets ''propelled'' down the [[gun barrel]], imparting high [[kinetic energy]] from the propellant gases and accelerating the projectile to its [[muzzle velocity]]. The projectile motion driven by the propellant inside the gun is known as the [[internal ballistics]].

==== Primer ====
[[File:Percussion caps.jpg|thumb|right|Percussion caps, the precursor of modern primers]]
[[File:Centerfire & rimfire ignition.gif|thumb|Comparison of primer ignition between centerfire (left two) and rimfire (right) ammunitions]]
[[File:Berdan vs boxer2.jpg|thumb|Flash hole profiles on Berdan (left) and Boxer (right) primers.]]
{{main|Primer (firearm)}}{{see also|Percussion cap}}
Because the main propellant charge is located deep inside the [[gun barrel]] and thus impractical to be directly lighted from the outside, an intermediate is needed to relay the [[fire making|ignition]]. In the earliest [[black powder]] [[muzzleloader]]s, a [[fuse (explosives)|fuse]] was used to direct a small flame through a [[touch hole]] into the barrel, which was slow and subjected to disturbance from environmental conditions. The next evolution was to have a small separate charge of finer gunpowder poured into a [[flash pan]], where it could start a "priming" ignition by an external source, when ignited the flame passed through a small hole in the side of the barrel to ignite the main gunpowder charge. 

The last evolution was to use a small [[percussion cap|metallic cap]] filled with a shock sensitive explosive compound that would ignite with a [[Hammer (firearms)|hammer]] strike. The source of ignition could be a burning [[slow match]] ([[matchlock]]) placed onto a [[touch hole]], a piece of [[pyrite]] ([[wheellock]])/[[flint]] ([[flintlock]]) striking a steel [[frizzen]], or a [[shock sensitivity|shock-sensitive]] brass or copper percussion cap ([[caplock]]) placed over a conical-shaped cone piece with a hollow pipe to create [[spark (fire)|spark]]s. When the primer powder starts combusting, the flame is transferred through an internal touch hole called a ''flash hole'' to provide [[activation energy]] for the main powder charge in the barrel. The disadvantage Is that the flash pan cAN still be exposed to the outside, making it difficult (or even impossible) to fire the gun in rainy or humid conditions as wet gunpowder burns poorly.

After [[Edward Charles Howard]] discovered [[fulminate]]s in 1800<ref>Howard, Edward (1800) [https://archive.org/details/bub_gb_dlFFAAAAcAAJ/page/n220 <!-- pg=204 --> "On a New Fulminating Mercury"], ''Philosophical Transactions of the Royal Society of London'' '''90''' (1): 204–238.</ref><ref>[https://www.npg.org.uk/collections/search/person/mp02292/edward-charles-howard Edward Charles Howard] {{Webarchive|url=https://web.archive.org/web/20210514052233/https://www.npg.org.uk/collections/search/person/mp02292/edward-charles-howard |date=14 May 2021 }} at National Portrait Gallery</ref> and the patent by [[Reverend]] [[Alexander John Forsyth]] expired in 1807,<ref name="Fadala2006">{{cite book|last=Fadala|first=Sam|title=The Complete Blackpowder Handbook|url=https://books.google.com/books?id=Dzxyneq43AEC&pg=PA160|date=17 November 2006|publisher=Gun Digest Books|location=Iola, Wisconsin|isbn=0-89689-390-1|pages=159–161}}{{Dead link|date=November 2023 |bot=InternetArchiveBot |fix-attempted=yes }}</ref> [[Joseph Manton]] invented the precursor [[percussion cap]] in 1814,<ref>{{cite book|author=Sam Fadala|title=The Complete Blackpowder Handbook|url=https://books.google.com/books?id=Dzxyneq43AEC&pg=PA158|year=2006|publisher=Krause Publications|isbn=978-0-89689-390-0|page=158}}{{Dead link|date=November 2023 |bot=InternetArchiveBot |fix-attempted=yes }}</ref> which was further developed in 1822 by the English-born American artist [[Joshua Shaw]],<ref>{{cite web|url=http://www.researchpress.co.uk/firearms/ignition/shaw02.htm |archive-url=https://web.archive.org/web/20120218221926/http://www.researchpress.co.uk/firearms/ignition/shaw02.htm |url-status=dead |archive-date=18 February 2012 |title=Joshua Shaw |access-date=5 November 2018}}</ref> and [[caplock]] [[fowling piece]]s appeared in [[Regency era]] England. These guns used a [[spring (device)|spring]]-loaded [[hammer (firearms)|hammer]] to strike a percussion cap placed over a [[conical]] "nipple", which served as both an "[[anvil]]" against the hammer strike and a transfer port for the sparks created by crushing the cap, and was easier and quicker to load, more resilient to weather conditions, and more reliable than the preceding flintlocks.<ref name="Fadala2006"/>

Modern primers are basically improved percussion caps with [[shock sensitivity|shock-sensitive]] chemicals (e.g. [[lead styphnate]]) enclosed in a small button-shaped capsule. In the early [[paper cartridge]]s, invented not long after the percussion cap, the primer was located deep inside the cartridge just behind the bullet, requiring a very thin and elongated [[firing pin]] to pierce the paper casing. Such guns were known as [[needle gun]]s, [[Dreyse needle gun|the most famous of which]] was decisive in the [[Kingdom of Prussia|Prussia]]n victory over the [[Austrian Empire|Austria]]ns at [[Battle of Königgrätz|Königgrätz]] in 1866. After the metallic cartridge was invented, the primer was relocated backward to the base of the case, either at the center of the case head ([[centerfire]]), inside the rim ([[rimfire ammunition|rimfire]]), inside a cup-like concavity of the case base (cupfire), in a pin-shaped sideways projection ([[pinfire]]), in a lip-like [[flange]] ([[Ethan Allen (armsmaker)#Cartridge pistols|lipfire]]), or in a small nipple-like bulge at the case base ([[teat-fire]]). Today, only the centerfire and rimfire have survived as the mainstream primer designs, while the pinfire also still exists but only in rare novelty miniature guns and a few very small [[blank cartridge]]s designed as noisemakers.

In rimfire ammunitions, the primer compound is [[injection moulding|moulded]] integrally into the interior of the protruding [[rim (firearms)|case rim]], which is crushed between the firing pin and the edge of the barrel breech (serving as the "anvil"). These ammunitions are thus not [[handloading|reload]]able, and are usually on the lower end of the [[muzzle energy|power]] spectrum, although due to the low [[manufacturing cost]] some of them (e.g. [[.22 Long Rifle]]) are among the most popular and prolific ammunitions currently being used.

Centerfire primers are a separately manufactured component, seated into a central recess at the case base known as the ''primer pocket'', and have two types: Berdan and Boxer. Berdan primers, patent by American inventor [[Hiram Berdan]] in 1866, are a simple capsule, and the corresponding case has two small flash holes with a bulged bar in between, which serves as the "anvil" for the primer. Boxer primers, patented by [[Royal Artillery]] colonel [[Edward Mounier Boxer]] also in 1866, are more complex and have an internal tripedal "anvil" built into the primer itself, and the corresponding case has only a single large central flash hole. Commercially, Boxer primers dominate the [[handloading|handloader]] market due to the ease of depriming and the ability to transfer sparks more efficiently.

Due to their small size and charge load, primers lack the power to shoot out the projectile by themselves, but can still put out enough energy to separate the bullet from the casing and push it partway into the barrel – a dangerous condition called a [[squib load]]. Firing a fresh cartridge behind a squib load obstructing the barrel will generate dangerously high pressure, leading to a [[catastrophic failure]] and potentially causing severe injuries when the gun blows apart in the shooter's hands. Actor [[Brandon Lee]]'s [[The Crow (1994 film)#Brandon Lee's death|infamous accidental death in 1993]] was believed to be caused by an undetected squib that was dislodged and shot out by a [[blank (cartridge)|blank]].

===Manufacturing===
[[File:0.30-30 Winchester case, stages in the drawing process, book; Cartridge Manufacture (1916), author; Douglas T. Hamilton.png|thumb|upright=1.6|.30–30 Winchester case, stages in the drawing process, book; from Hamilton<ref name=":0">{{Cite book |url=http://archive.org/details/cartridgemanufac00hamirich |title=Cartridge manufacture; a treatise covering the manufacture of rifle cartridge cases, bullets, powders, primers and cartridge clips, and the designing and making of the tools used in connection with the production of cartridge cases and bullets |last=Hamilton |first=Douglas Thomas |date=1916 |location=New York |publisher=The Industrial Press |access-date=8 April 2019 |archive-url=https://web.archive.org/web/20170606192744/https://archive.org/details/cartridgemanufac00hamirich |archive-date=6 June 2017 |url-status=live }}</ref>]]
Beginning in the 1860s, early metallic cartridges (e. g. for the [[Montigny mitrailleuse]]<ref>{{cite web | url=https://www.victorianshipmodels.com/antitorpedoboatguns/Mitrailleuse/mitrailleuseammu.html | title=Mitrailleuse Ammunition | access-date=10 August 2022 | archive-date=18 October 2021 | archive-url=https://web.archive.org/web/20211018081700/http://www.victorianshipmodels.com/antitorpedoboatguns/Mitrailleuse/mitrailleuseammu.html | url-status=live }}</ref> or the [[Snider–Enfield]] rifle<ref>{{cite web | url=https://sites.google.com/site/britmilammo/-577-inch-snider/-577-inch-ball-pattern-i-to-v | title=British Military Small Arms Ammo - .577 inch Ball Pattern I to V | access-date=10 August 2022 | archive-date=10 August 2022 | archive-url=https://web.archive.org/web/20220810113235/https://sites.google.com/site/britmilammo/-577-inch-snider/-577-inch-ball-pattern-i-to-v | url-status=live }}</ref>) were produced similarly to the paper cartridges, with sides made from thick paper, but with copper (later brass) foil supporting the base of the cartridge and some more details in it holding the primer. In the 1870s, brass foil covered all of the cartridge, and the technology to make solid cases, in which the metallic cartridges described below were developed, but before the 1880s, it was far too expensive and time-consuming for mass production<ref>{{cite web | url=https://sites.google.com/site/britmilammo/-450-inch-martini-henry/-45-martini-henry-drawn-case | title=British Military Small Arms Ammo - .45 Martini-Henry Solid Case Rifle | access-date=10 August 2022 | archive-date=10 August 2022 | archive-url=https://web.archive.org/web/20220810113236/https://sites.google.com/site/britmilammo/-450-inch-martini-henry/-45-martini-henry-drawn-case | url-status=live }}</ref> and the metallurgy was not yet perfected.<ref>{{cite web | url=http://www.victorianshipmodels.com/antitorpedoboatguns/Hotchkiss/hotchkissammunit.html | title=Hotchkiss Ammunition | access-date=10 August 2022 | archive-date=5 May 2022 | archive-url=https://web.archive.org/web/20220505235020/http://www.victorianshipmodels.com/antitorpedoboatguns/Hotchkiss/hotchkissammunit.html | url-status=live }}</ref>

To manufacture cases for cartridges, a sheet of brass is punched into disks. These disks go through a series of [[deep drawing|drawing dies]]. The disks are [[annealing (metallurgy)|annealed]] and washed before moving to the next series of dies. The brass needs to be annealed to remove the work-hardening in the material and make the brass malleable again ready for the next series of dies.<ref name=":0"/>

Manufacturing bullet jackets is similar to making brass cases: there is a series of drawing steps with annealing and washing.<ref name=":0" />

===Specifications===
Critical cartridge specifications include neck size, bullet weight and [[caliber]], maximum pressure, [[headspace (firearms)|headspace]], overall length, case body diameter and taper, shoulder design, [[Rim (firearms)|rim type]], etc. Generally, every characteristic of a specific cartridge type is tightly controlled and few types are interchangeable in any way. Exceptions do exist but generally, these are only where a shorter cylindrical rimmed cartridge can be used in a longer chamber, (e.g., .22 Short in .22 Long Rifle chamber, .32 H&R Magnum in .327 Federal Magnum chamber, and .38 Special in a .357 Magnum chamber). [[Centerfire ammunition|Centerfire]] primer type (Boxer or Berdan, see below) is interchangeable, although not in the same case. Deviation in any of these specifications can result in firearm damage and, in some instances, injury or death. Similarly, the use of the wrong type of cartridge in any given gun can damage the gun, or cause bodily injury.

Cartridge specifications are determined by several standards organizations, including [[SAAMI]] in the United States, and [[C.I.P.]] in many European states. NATO also performs [[NATO EPVAT testing|its own tests]] for military cartridges for its member nations; due to differences in testing methods, NATO cartridges ([[headstamp]]ed with the NATO cross) may present an unsafe combination when loaded into a weapon chambered for a cartridge certified by one of the other testing bodies.<ref>{{cite web|url=http://www.saami.org/specifications_and_information/publications/download/SAAMI_ITEM_211-Unsafe_Arms_and_Ammunition_Combinations.pdf |title=Unsafe Firearm-Ammunition Combinations |publisher=SAAMI |date=6 March 2012 |access-date=4 November 2013 |url-status=dead |archive-url=https://web.archive.org/web/20131116092917/http://saami.org/specifications_and_information/publications/download/SAAMI_ITEM_211-Unsafe_Arms_and_Ammunition_Combinations.pdf |archive-date=16 November 2013}}</ref>

Bullet diameter is measured either as a fraction of an inch (usually in 1/100 or in 1/1000) or in millimeters. Cartridge case length can also be designated in inches or millimeters.

==History==
{{More citations needed section|date=February 2014}}
[[File:US paper to centerfire rounds.jpg|thumb|upright=1.35|US Cartridges 1860–1875<br />
('''1''') Colt Army 1860 .44 paper cartridge, [[American Civil War]]<br />
('''2''') Colt Thuer-Conversion .44 revolver cartridge, patented in 1868<br />
('''3''') .44 Henry rim fire cartridge flat<br />
('''4''') .44 Henry rim fire cartridge pointed<br />
('''5''') Frankford Arsenal .45 Colt cartridge, Benét ignition<br />
('''6''') Frankford Arsenal .45 Colt-Schofield cartridge, Benét ignition]]
[[File:Festungsmuseum Reuenthal Sonderausstellung Zuleger britische Patronen.JPG|thumb|right|Historic British cartridges]]
[[Paper cartridge]]s have been in use for centuries, with a number of sources dating their usage as far back as the late 14th and early 15th centuries. Historians note their use by soldiers of [[Christian I, Elector of Saxony]] and [[Christian II, Elector of Saxony|his son]] in the late 16th century,<ref name="greener" /><ref>{{cite book|title=The Art of Chivalry: European Arms and Armor from the Metropolitan Museum of Art|last1=Nickel|first1=Helmut|last2=Pyhrr|first2=Stuart W.|last3=Tarassuk|first3=Leonid|page=174|year=2013|publisher=Yale University Press |isbn=978-0300199413}}</ref> while the [[Dresden Armoury]]<!-- Patronenstocke --> has evidence dating their use to 1591.<ref>{{cite journal|title=The Rudolph J. Nunnemacher Collection of Projectile Arms |last1=Metschl|first1=John|journal=Bulletin of the Public Museum of the City of Milwaukee|volume=9|year=1928|page=60}}</ref><ref name="greener" /> Capo Bianco wrote in 1597 that paper cartridges had long been in use by Neapolitan soldiers. Their use became widespread by the 17th century.<ref name=greener>{{Citation |title=The Gun and Its Development |chapter=Ammunition and Accessories.–Cartridges |first=William Wellington |last=Greener |year=1907 |publisher=Cassell |url=https://books.google.com/books?id=3HMCAAAAYAAJ |pages=570, 589 |access-date=22 March 2017 |archive-url=https://web.archive.org/web/20150322023527/http://books.google.com/books?id=3HMCAAAAYAAJ |archive-date=22 March 2015 |url-status=live }}</ref> The 1586 round consisted of a charge of [[gunpowder|powder]] and a bullet in a paper cartridge. Thick paper is still known as "[[cartridge paper]]" from its use in these cartridges.<ref>''Oxford English Dictionary'', article on "cartridge" (subsection: "cartridge-paper").</ref> Another source states the cartridge appeared in 1590.<ref name="ArmyTM">{{Citation |last=U.S. Army |title=Military Explosives |publisher=Department of the Army |series=Technical Manual |id=TM 9-1300-214 |date=September 1984}}, p. 2-3<!--hypenated pagenumber-->, stating "1590. Cartridges with ball and power combined were introduced for small arms."</ref> King [[Gustavus Adolphus of Sweden]] had his troops use cartridges in the 1600s.<ref>{{Harvnb|U.S. Army|1984|pp=2–3}} indicates the period 1611–1632 and states the improved cartridge increased the rate of fire for the [[Thirty Years' War]].</ref> The paper formed a cylinder with twisted ends; the ball was at one end, and the measured powder filled the rest.<ref>{{Citation |last=Sharpe |first=Philip B. |year=1938 |title=The Rifle in America |chapter=The Development of the Cartridge |location=New York |publisher=William Morrow }}, pp. 29–30.</ref>

This cartridge was used with [[muzzle-loading]] military firearms, probably more often than for sporting shooting, the base of the cartridge being ripped or bitten off by the soldier, the powder poured into the barrel, and the paper and bullet rammed down the barrel.<ref>{{harvnb|Greener|1907|p=570}}</ref> In the US Civil War era cartridge, the paper was supposed to be discarded, but soldiers often used it as a wad.<ref>{{harvnb|Sharpe|1938|p=30}}</ref> To ignite the charge an additional step was required where a finer-grained powder called priming powder was poured into the pan of the gun to be ignited by the firing mechanism.

The evolving nature of warfare required a firearm that could load and fire more rapidly, resulting in the flintlock musket (and later the Baker rifle), in which the pan was covered by furrowed steel. This was struck by the flint and fired the gun. In the course of loading, a pinch of powder from the cartridge would be placed into the pan as priming, before the rest of the cartridge was rammed down the barrel, providing charge and wadding.<ref>{{cite book|title=Edgehill: The Battle Reinterpreted|last1=Scott|first1=Christopher L.|last2=Turton|first2=Alan|last3=Gruber von Arni|first3=Eric|pages=9–12|year=2004|isbn=978-1844152544|publisher=Pen and Sword}}</ref>

Later developments rendered this method of priming unnecessary, as, in loading, a portion of the charge of powder passed from the barrel through the vent into the pan, where it was held by the cover and hammer. {{Citation needed|date=June 2011}}

The next important advance in the method of ignition was the introduction of the copper [[percussion cap]]. This was only generally applied to the British military musket (the [[Brown Bess]]) in 1842, a quarter of a century after the invention of percussion powder and after an elaborate government test at Woolwich in 1834. The invention that made the percussion cap possible was patented by the Rev. [[Alexander John Forsyth|A. J. Forsyth]] in 1807 and consisted of priming with a fulminating powder made of [[potassium chlorate]], sulfur, and charcoal, which ignited by concussion. This invention was gradually developed, and used, first in a steel cap, and then in a copper cap, by various gunmakers and private individuals before coming into general military use nearly thirty years later.{{Citation needed|date=June 2011}}

The alteration of the military flint-lock to the percussion [[musket]] was easily accomplished by replacing the powder pan with a perforated nipple and by replacing the cock or hammer that held the flint with a smaller hammer that had a hollow to fit on the nipple when released by the trigger. The shooter placed a percussion cap (now made of three parts of [[potassium chlorate]], two of [[mercury fulminate|fulminate of mercury]] and powdered glass) on the nipple. The detonating cap thus invented and adopted brought about the invention of the modern cartridge case, and rendered possible the general adoption of the [[Breech-loading weapon|breech-loading]] principle for all varieties of rifles, shotguns, and [[pistol]]s. This greatly streamlined the reloading procedure and paved the way for semi- and full-automatic firearms.{{Citation needed|date=June 2011}}

However, this big leap forward came at a price: it introduced an extra component into each round—the cartridge case—which had to be removed before the gun could be reloaded. While a flintlock, for example, is immediately ready to reload once it has been fired, adopting brass cartridge cases brought in the problems of extraction and ejection. The mechanism of a modern gun must not only load and fire the piece but also provide a method of removing the spent case, which might require just as many added moving parts. Many [[Firearm malfunction|malfunctions]] occur during this process, either through a failure to extract a case properly from the chamber or by allowing the extracted case to jam the action. Nineteenth-century inventors were reluctant to accept this added complication and experimented with a variety of [[caseless]] or self-consuming cartridges before finally accepting that the advantages of brass cases far outweighed this one drawback.<ref>Winant, Lewis (1959). Early Percussion Firearms. Great Britain: Herbert Jenkins Ltd. pp. 145–146. {{ISBN|0-600-33015-X}}</ref>

===Integrated cartridges===
[[File:Chassepot paper cartridge.jpg|thumb|[[Chassepot]] paper cartridge (1866)]]
The first integrated cartridge was developed in Paris in 1808 by the Swiss gunsmith [[Jean Samuel Pauly]] in association with French gunsmith [[François Prélat]]. Pauly created the first fully self-contained cartridges:<ref name="Smyth">[https://books.google.com/books?id=dHbHS5GhCN4C&dq=Jean+Samuel+Pauly&pg=PA24 "Chemical Analysis of Firearms, Ammunition, and Gunshot Residue"] {{Webarchive|url=https://web.archive.org/web/20160425212326/https://books.google.com/books?id=dHbHS5GhCN4C&pg=PA24&dq=Jean+Samuel+Pauly |date=25 April 2016 }} by James Smyth Wallace p. 24.</ref> the cartridges incorporated a copper base with integrated [[mercury fulminate]] primer powder (the major innovation of Pauly), a round bullet and either brass or paper casing.<ref name="sil.si.edu">http://www.sil.si.edu/smithsoniancontributions/HistoryTechnology/pdf_hi/SSHT-0011.pdf {{Webarchive|url=https://web.archive.org/web/20151119200042/http://www.sil.si.edu/smithsoniancontributions/HistoryTechnology/pdf_hi/SSHT-0011.pdf |date=19 November 2015 }}.</ref><ref name="Pauly">[https://books.google.com/books?id=izGOfMdSm2IC&dq=Jean+Samuel+Pauly&pg=PA94 ''Firearms''] {{Webarchive|url=https://web.archive.org/web/20160521112943/https://books.google.com/books?id=izGOfMdSm2IC&pg=PA94&dq=Jean+Samuel+Pauly |date=21 May 2016 }} by Roger Pauly p. 94.</ref> The cartridge was loaded through the breech and fired with a needle. The needle-activated centerfire [[breech-loading]] gun would become a major feature of firearms thereafter.<ref>[https://books.google.com/books?id=GmQVan-M3ykC&dq=Jean+Samuel+Pauly&pg=PA121 A History of Firearms] {{Webarchive|url=https://web.archive.org/web/20160507003545/https://books.google.com/books?id=GmQVan-M3ykC&pg=PA121&dq=Jean+Samuel+Pauly&lr= |date=7 May 2016 }} by W. Y. Carman p. 121.</ref> Pauly made an improved version, protected by a patent, on 29 September 1812.<ref name="Smyth"/>

Probably no invention connected with firearms has wrought such changes in the principle of gun construction as those effected by the "expansive cartridge case". This invention has completely revolutionized the art of gun making, has been successfully applied to all descriptions of firearms and has produced a new and important industry: that of cartridge manufacture. Its essential feature is preventing gas from escaping the breech when the gun is fired, by means of an expansive cartridge case containing its own means of ignition. Previous to this invention shotguns and sporting rifles were loaded by means of [[powder flask]]s and shot bags or flasks, bullets, wads, and copper caps, all carried separately. One of the earliest efficient modern cartridge cases was the [[pinfire cartridge]], developed by French gunsmith [[Casimir Lefaucheux]] in 1836.<ref name="Pistols">Kinard, Jeff (2004) ''Pistols: An Illustrated History of Their Impact'', ABC-CLIO, [https://books.google.com/books?id=ZVnuHX_6bG0C&dq=Houllier+cartridge&pg=PA109 p. 109] {{Webarchive|url=https://web.archive.org/web/20160528211811/https://books.google.com/books?id=ZVnuHX_6bG0C&pg=PA109&dq=Houllier+cartridge#PPA109,M1 |date=28 May 2016 }}</ref> It consisted of a thin weak shell made of brass and paper that expanded from the force of the explosion. This fit perfectly in the barrel and thus formed an efficient gas check. A small percussion cap was placed in the middle of the base of the cartridge and was ignited by means of a brass pin projecting from the side and struck by the hammer. This pin also afforded the means of extracting the cartridge case. This cartridge was introduced in England by Lang, of Cockspur Street, London, about 1845.

In the [[American Civil War]] (1861–1865) a breech-loading rifle, the [[Sharps rifle|Sharps]], was introduced and produced in large numbers. It could be loaded with either a ball or a [[paper cartridge]]. After that war, many were converted to the use of metal cartridges. The development by [[Smith & Wesson]] (among many others) of revolver handguns that used metal cartridges helped establish cartridge firearms as the standard in the United States by the late 1860s and early 1870s, although many continue to use percussion revolvers well after that.<ref>{{Cite web |url=http://www.cabelas.com/category/Pistols-Revolvers/104503680.uts |title=Cabela's still sells black powder pistols; remain in use for hunting |access-date=22 March 2017 |archive-url=https://web.archive.org/web/20170322111737/http://www.cabelas.com/category/Pistols-Revolvers/104503680.uts |archive-date=22 March 2017 |url-status=live }}</ref>

===Modern metallic cartridges===
[[File:Snider-Martini-Enfield Cartridges.JPG|thumb|(From Left to Right): A [[.577 Snider]] cartridge (1867), a [[.577/450 Martini-Henry]] cartridge (1871), a later drawn brass .577/450 [[Martini-Henry]] cartridge, and a [[.303 British]] Mk VII SAA Ball cartridge.]]
[[File:Fusil Gras M80 1874 metallic cartridge.jpg|thumb|French Army [[Fusil Gras mle 1874]] metallic cartridge.]]
[[File:8mm Lebel Tarbes-01.jpg|thumb|upright=.6|The [[8 mm Lebel]] ammunition, developed in 1886, was the first [[smokeless powder|smokeless gunpowder]] cartridge to be created and adopted by any country.]]

Most of the early all-metallic cartridges were of the [[pinfire]] and [[rimfire ammunition|rimfire]] types.

The first centerfire metallic cartridge was invented by [[Jean Samuel Pauly]] in the first decades of the 19th century. However, although it was the first cartridge to use a form of [[obturation]], a feature integral to a successful breech-loading cartridge, Pauly died before it was converted to percussion cap ignition.

Frenchman [[Louis-Nicolas Flobert]] invented the first [[rimfire ammunition|rimfire metallic cartridge]] in 1845. His cartridge consisted of a percussion cap with a bullet attached to the top.<ref>[http://www.firearmsadvantage.com/history_of_firearms.html "History of firearms"] {{webarchive|url=https://web.archive.org/web/20151222090129/http://www.firearmsadvantage.com/history_of_firearms.html |date=22 December 2015 }} (fireadvantages.com)</ref><ref>[http://www.firearmsadvantage.com/how_guns_work.html "How guns work"] {{webarchive|url=https://web.archive.org/web/20151222103328/http://www.firearmsadvantage.com/how_guns_work.html |date=22 December 2015 }} (fireadvantages.com)</ref> Flobert then made what he called "[[gallery gun|parlor guns]]" for this cartridge, as these rifles and pistols were designed to be shot in indoor shooting parlors in large homes.<ref>{{cite book|title =Flayderman's Guide to Antique American Firearms and Their Values|page=775|first= Norm |last=Flayderman |edition= 9|publisher =F+W Media, Inc|year= 2007 |location=Iola, Wisconsin|isbn =978-0-89689-455-6 }}</ref><ref name="BarnesBodinson2009">{{cite book|last1=Barnes|first1=Frank C.|author-link=Frank Barnes (gunsmith)|last2=Bodinson|first2=Holt|title=Cartridges of the World: A Complete and Illustrated Reference for Over 1500 Cartridges|chapter-url=https://books.google.com/books?id=3_-kUkNXTNwC&pg=PA441|access-date=25 January 2012|year=2009|publisher=Gun Digest Books|location=Iola, Wisconsin|isbn=978-0-89689-936-0|page=441|chapter=Amrerican Rimfire Cartridges}}{{Dead link|date=November 2023 |bot=InternetArchiveBot |fix-attempted=yes }}</ref> These [[6mm Flobert]] cartridges do not contain any powder. The only [[propellant]] substance contained in the cartridge is the percussion cap.<ref>[http://www.arquebusiers.be/section-tir.htm Shooting section (''la section de tir'')] {{webarchive|url=https://web.archive.org/web/20131110001815/http://www.arquebusiers.be/section-tir.htm |date=10 November 2013 }} of the official website (in French) of a modern indoor shooting association in Belgium, ''Les Arquebusier de Visé''.</ref> In English-speaking countries, the 6mm Flobert cartridge corresponds to [[.22 BB Cap]] and [[.22 CB Cap]] ammunition. These cartridges have a relatively low muzzle velocity of around 700&nbsp;ft/s (210&nbsp;m/s).

French gunsmith [[Benjamin Houllier]] improved the Lefaucheux pinfire cardboard cartridge and patented in Paris in 1846, the first fully metallic pinfire cartridge containing powder in a metallic cartridge.<ref name="Pistols"/><ref>''[http://trabuc.perso.sfr.fr/mapage/les-lefaucheux.pdf Les Lefaucheux] {{Webarchive|url=https://web.archive.org/web/20131008064628/http://trabuc.perso.sfr.fr/mapage/les-lefaucheux.pdf |date=8 October 2013 }}'', by Maître Simili, Spring 1990 (in French)</ref> He also included in his patent claims rim and centerfire primed cartridges using brass or copper casings.<ref name="sil.si.edu"/> Houllier commercialised his weapons in association with the gunsmiths Blanchard or Charles Robert.<ref>{{cite web |url=http://www.littlegun.info/arme%20francaise/artisans%20e%20f%20g%20h%20i%20j/a%20houllier%20blanchar%20gb.htm |title=An example of a Benjamin Houllier gun manufactured in association with the gunsmith Blanchard |publisher=Littlegun.info |access-date=4 November 2013 |archive-url=https://web.archive.org/web/20130823172928/http://www.littlegun.info/arme%20francaise/artisans%20e%20f%20g%20h%20i%20j/a%20houllier%20blanchar%20gb.htm |archive-date=23 August 2013 |url-status=live }}</ref><ref>{{cite web |url=http://www.littlegun.info/arme%20francaise/artisans%20e%20f%20g%20h%20i%20j/a%20houllier%20blanchar%20et%20ch%20robert%20gb.htm |title=An example of a Benjamin Houllier gun manufactured in association with the gunsmiths Blanchard and Charles Robert |publisher=Littlegun.info |access-date=4 November 2013 |archive-url=https://web.archive.org/web/20130823161754/http://www.littlegun.info/arme%20francaise/artisans%20e%20f%20g%20h%20i%20j/a%20houllier%20blanchar%20et%20ch%20robert%20gb.htm |archive-date=23 August 2013 |url-status=live }}</ref>

In the United States, in 1857, the Flobert cartridge inspired the [[.22 Short]], specially conceived for the first American revolver using rimfire cartridges, the [[Smith & Wesson Model 1]]. A year before, in 1856, the [[LeMat revolver]] was the first American breech-loading firearm, but it used pinfire cartridges, not rimfire. Formerly, an employee of the [[Colt's Manufacturing Company|Colt's Patent Firearms Manufacturing Company]], [[Rollin White]], had been the first in America to conceive the idea of having the revolver cylinder bored through to accept metallic cartridges ([[wikt:circa|circa]] 1852), with the first in the world to use bored-through cylinders probably having been Lefaucheux in 1845, who invented a pepperbox-revolver loaded from the rear using bored-through cylinders.<ref>{{cite web|url=https://books.google.com/books?id=DjWpnQEACAAJ&q=Early+Percussion+Firearms|title=Early Percussion Firearms|publisher=Spring Books|date=25 October 2015|access-date=7 November 2020|archive-date=10 March 2024|archive-url=https://web.archive.org/web/20240310102435/https://books.google.com/books?id=DjWpnQEACAAJ&q=Early+Percussion+Firearms|url-status=live}}</ref> Another possible claimant for the bored-through cylinder is a Frenchman by the name of Perrin, who allegedly produced in 1839 a pepperbox revolver with a bored-through cylinder to order. Other possible claimants include Devisme of France in 1834 or 1842 who claimed to have produced a breech-loading revolver in that period though his claim was later judged as lacking in evidence by French courts and Hertog & Devos and Malherbe & Rissack of Belgium who both filed patents for breech-loading revolvers in 1853.<ref>{{Cite web|url=https://books.google.com/books?id=SzEwAQAAMAAJ&q=Perrin+1839+Arme&pg=PA186|title=Annales de la propriété industrielle, artistique et littéraire|date=10 April 1863|publisher=Au bureau des Annales|via=Google Books|access-date=7 November 2020|archive-date=10 March 2024|archive-url=https://web.archive.org/web/20240310102427/https://books.google.com/books?id=SzEwAQAAMAAJ&q=Perrin+1839+Arme&pg=PA186#v=snippet&q=Perrin%201839%20Arme&f=false|url-status=live}}</ref> However, [[Samuel Colt]] refused this innovation. White left Colt, went to Smith & Wesson to rent a license for his patent, and this is how the S&W Model 1 saw the light of day in 1857. The patent didn't definitely expire until 1870, allowing Smith & Wesson competitors to design and commercialize their own revolving breech-loaders using metallic cartridges. Famous models of that time are the Colt [[Colt Model 1871-72 Open Top|Open Top]] (1871–1872) and [[Colt Single Action Army|Single Action Army "Peacemaker"]] (1873). But in rifles, the [[lever-action]] mechanism patents were not obstructed by Rollin White's [[patent infringement]] because White only held a patent concerning drilled cylinders and revolving mechanisms. Thus, larger caliber rimfire cartridges were soon introduced after 1857, when the Smith & Wesson .22 Short ammunition was introduced for the first time. Some of these rifle cartridges were used in the American Civil War, including the [[.44 Henry]] and [[56-56 Spencer]] (both in 1860). However, the large rimfire cartridges were soon replaced by [[centerfire]] cartridges, which could safely handle higher pressures.<ref>[[Cartridges of the World]], various editions and articles.</ref><ref name="Williamson">{{citation|first=Harold F. |last=Williamson |title=Winchester: The Gun that Won the West |date=1952 |publisher=A. S. Barnes |isbn=978-0498083150 <!--1961 is second printing not second edition --> |page=66 |quote=The rimfire cartridge, which was used so successfully in the Henry and the Model 66, was limited to relatively weak loads of powder and comparatively lightweight bullets.  These limitations, which still apply, came from the construction of the rimfire cartridge and from the action of the priming mixture.  Rimfire cartridges must be made of thin metal or the firing pin cannot indent the head and explode the primer.  This thin-walled cartridge case limits the pressure developed by the powder charge and consequently the weight of the bullet.  If too much powder is used, there is a danger that the cartridge case will burst at the folded rim when it is fired, and that the primer flash, passing laterally across the rear of the powder charge, will not ignite a large load sufficiently to consume all of the powder before the bullet leaves the cartridge case. These limitations were overcome with the development of the centerfire cartridge....}}</ref>

In 1867, the British war office adopted the [[Eley Brothers|Eley]]–[[Edward Mounier Boxer|Boxer]] metallic centerfire cartridge case in the [[Pattern 1853 Enfield]] rifles, which were converted to [[Snider-Enfield]] breech-loaders on the Snider principle. This consisted of a block opening on a hinge, thus forming a false breech against which the cartridge rested. The priming cap was in the base of the cartridge and was discharged by a [[Firing pin#Firing pin vs. striker|striker]] passing through the breech block. Other European powers adopted breech-loading military rifles from 1866 to 1868, with paper instead of metallic cartridge cases. The original Eley-Boxer cartridge case was made of thin-coiled brass—occasionally these cartridges could break apart and jam the breech with the unwound remains of the case upon firing. Later the solid-drawn, centerfire cartridge case, made of one entire solid piece of tough hard metal, an alloy of copper, with a solid head of thicker metal, has been generally substituted.{{Citation needed|date=June 2011}}

Centerfire cartridges with solid-drawn metallic cases containing their own means of ignition are almost universally used in all modern varieties of military and sporting rifles and pistols.{{Citation needed|date=June 2011}}

Around 1870, machined tolerances had improved to the point that the cartridge case was no longer necessary to seal a firing chamber. Precision-faced bolts would seal as well, and could be economically manufactured.{{Citation needed|date=June 2011}} However, normal wear and tear proved this system to be generally infeasible.

=== Factory vs. handloading ===
{{main|Handloading}}
{{see also|Wildcat cartridge}}

==Nomenclature==
The name of any given cartridge does not necessarily reflect any cartridge or gun dimension. The name is merely the standardized and accepted moniker. SAAMI (Sporting Arms and Ammunition Manufacturers' Institute) and the European counterpart (CIP) and members of those organizations specify correct cartridge names.

It is incomplete to refer to a cartridge as a certain "[[caliber]]" (e.g., "30-06 caliber"), as the word ''caliber'' only describes the bullet diameter. The correct full name for this round is [[.30-06 Springfield|.30–'06 Springfield]].  The "-'06" means it was introduced in 1906. In sporting arms, the only consistent definition of "caliber" is bore diameter, and dozens of unique [[.30-caliber]] round types exist.

There is considerable variation in cartridge nomenclature. Names sometimes reflect various characteristics of the cartridge. For example, the .308 Winchester uses a bullet of 308/1000-inch diameter and was standardized by Winchester. Conversely, cartridge names often reflect nothing related to the cartridge in any obvious way. For example, the .218 Bee uses a bullet of 224/1000-inch diameter, fired through a .22-in bore, etc. The 218 and Bee portions of this cartridge name reflect nothing other than the desires of those who standardized that cartridge. Many similar examples exist, for example: .219 Zipper, .221 Fireball, .222 Remington, .256 Winchester, .280 Remington, .307 Winchester, .356 Winchester.

Where two numbers are used in a cartridge name, the second number may reflect a variety of things. Frequently the first number reflects bore diameter (inches or millimeters). The second number reflects case length (in inches or mm). For example, the [[7.62×51mm NATO]] refers to a bore diameter of 7.62&nbsp;mm and has an overall case length of 51&nbsp;mm, with a total length of 71.1&nbsp;mm. The commercial version is the [[.308 Winchester]].

In older [[black powder]] cartridges, the second number typically refers to powder charge, in [[Grain (unit)|grains]]. For example, the [[.50-90 Sharps]] has a .50-inch bore and used a nominal charge of {{convert|90.0|gr|g}} of black powder.

Many such cartridges were designated by a three-number system (e.g., 45–120–3{{frac|1|4}} Sharps: 45-caliber bore, 120 grains of (black) powder, 3{{frac|1|4}}-inch long case). Other times, a similar three-number system indicated bore (caliber), charge (grains), and bullet weight (grains). The 45-70-500 Government is an example.

Often, the name reflects the company or individual who standardized it, such as the [[.30 Newton]], or some characteristic important to that person.

The [[.38 Special]] actually has a nominal bullet diameter of {{convert|0.3570|in}} (jacketed) or {{convert|0.3580|in}} (lead) while the case has a nominal diameter of {{convert|0.3800|in}}, hence the name. This is historically logical: the hole drilled through the chambers of .36-caliber cap-and-ball revolvers when converting those to work with cartridges was {{convert|0.3800|in}}, and the cartridge made to work in those revolvers was logically named the [[.38 Short Colt|.38 Colt]]. The original cartridges used a heeled bullet like a .22 rimfire where the bullet was the same diameter as the case. Early Colt Army .38s have a bore diameter that will allow a .357" diameter bullet to slide through the barrel. The cylinder is bored straight through with no step. Later versions used an inside the case lubricated bullet of .357" diameter instead of the original .38" with a reduction in bore diameter. The difference in .38 Special bullet diameter and case diameter reflects the thickness of the case mouth (approximately 11/1000-inch per side). The [[.357 Magnum]] evolved from the .38 Special. The .357 was named to reflect bullet diameter (in thousandths inch), not case diameter. "Magnum" was used to indicate its longer case and higher operating pressure.

==Classification==
Cartridges are classified by some major characteristics. One classification is the location of the primer. Early cartridges began with the pinfire, then the rimfire, and finally the centerfire.

[[File:Simpified schematic of blowback mechanism with advanced primer ignition.png|thumb|Schematic of an Advanced Primer Blowback operation using a rebated rim cartridge (bottlenecked). The rebated rim allows the bolt to enter the chamber with the round to be fired in forward travel just before the cartridge in-battery position.]]

Another classification describes how cartridges are located in the chamber ([[headspace (firearms)|headspace]]). Rimmed cartridges are located with the rim near the cartridge head; the rim is also used to extract the cartridge from the chamber. Examples are the [[.22 long rifle]] and [[.303 British]]. In a rimless cartridge, the cartridge head diameter is about the same as or smaller than the body diameter. The head will have a groove so the cartridge can be extracted from the chamber. Locating the cartridge in the chamber is accomplished by other means. Some rimless cartridges are necked down, and they are positioned by the cartridge's shoulder. An example is the [[.30-06 Springfield]]. Pistol cartridges may be located by the end of the brass case. An example is the [[.45 ACP]]. A [[belted magnum|belted cartridge]] has a larger diameter band of thick metal near the head of the cartridge. An example is the [[.300 Weatherby Magnum]]. An extreme version of the rimless cartridge is the rebated case; guns employing [[Blowback (firearms)#Advanced primer ignition (API) blowback|advanced primer ignition]] need such a case because the case moves during firing (i.e., it is not located at a fixed position). An example is the [[Oerlikon 20 mm cannon|20mm×110RB]].

===Centerfire===
[[File:Fired rimfire and centerfire casings.jpg|thumb|Fired rimfire (left) and centerfire (right) cartridges. A rimfire [[firing pin]] produces a notch at the edge of the rim; a centerfire pin produces a divot in the center of the primer.]]
{{Main|Centerfire ammunition}}
A centerfire cartridge has a centrally located primer held within a recess in the case head. Most centerfire brass cases used worldwide for sporting ammunition use [[Boxer primer]]s. It is easy to remove and replace Boxer primers using standard reloading tools, facilitating reuse.

Some European- and Asian-manufactured military and sporting ammunition uses [[Berdan primer]]s. Removing the spent primer from (decapping) these cases requires the use of a special tool because the primer anvil (on which the primer compound is crushed) is an integral part of the case and the case, therefore, does not have a central hole through which a decapping tool can push the primer out from the inside, as is done with Boxer primers. In Berdan cases, the flash holes are located to the sides of the anvil. With the right tool and components, reloading Berdan-primed cases is perfectly feasible. However, Berdan primers are not readily available in the U.S.

===Rimfire===
[[File:Rim fire.svg|thumb|Schematic of a rimfire cartridge and its ignition]]
{{Main|Rimfire ammunition}}
Rimfire priming was a popular solution before centerfire priming was perfected. In a rimfire case, centrifugal force pushes a liquid priming compound into the internal recess of the folded rim as the manufacturer spins the case at a high rate and heats the spinning case to dry the priming compound mixture in place within the hollow cavity formed within the rim fold at the perimeter of the case interior.

In the mid to late 19th century, many rimfire cartridge designs existed. Today only a few, mostly for use in small-caliber guns, remain in general and widespread use. These include the .17 Mach II, .17 Hornady Magnum Rimfire (HMR), 5mm Remington Magnum (Rem Mag), .22 (BB, CB, Short, Long, Long Rifle), and .22 Winchester Magnum Rimfire (WMR).

Compared to modern centerfire cases used in the strongest types of modern guns, existing rimfire cartridge designs use loads that generate relatively low chamber pressures because of limitations of feasible gun design, as the rim has little or no lateral support from the gun. Such support would require very close tolerances in the design of the chamber, bolt, and firing pin. Because that is not cost-effective method, it is necessary to keep rimfire load pressure low enough so that the stress generated by chamber pressure would not push the case rim outward and cause the rim to expand significantly. Also, the wall of the folded rim must be both thin and ductile enough to easily deform, as necessary to allow the blow from the firing pin to crush the rim, thereby igniting the primer compound, and it must do so without rupturing the case. If the rim is too thick, it will be too resistant to deformation and if it is too hard, the rim will be to brittle and crack, rather than deform.<ref name="Williamson"/>

Modern centerfire cartridges are often loaded to {{convert|65000|psi|MPa|abbr=on}} maximum chamber pressure. Conversely, no commercialized rimfire has ever been loaded above {{convert|40000|psi|MPa|abbr=on}} maximum chamber pressure. However, with careful gun design and production, no fundamental reason exists that higher pressures could not be used. Despite the relative lower chamber pressure, modern rimfire magnums are commonly found in .17-caliber (4.5&nbsp;mm), .20-caliber (5mm), and .22-caliber (5.6&nbsp;mm) that can generate muzzle energies comparable to smaller caliber centerfire cartridges.{{Citation needed|date=May 2012}}

Today, [[.22 LR]] (.22 Long Rifle) accounts for the vast majority of all rimfire ammunition produced. Standard .22 LR rounds use an essentially pure lead bullet plated with a typical 95% copper, 5% zinc combination. These are offered in [[supersonic]] and subsonic types, as well as target shooting, plinking, and hunting versions. These cartridges are usually coated with hard wax for fouling control.

The .22 LR and related .22 rimfire cartridges use a [[heeled bullet]], where the external diameter of the case is the same as the diameter of the forward portion of the bullet and where the rearward portion of the bullet, which extends into the case, is necessarily smaller in diameter than the main body of the bullet.

==Semi-automatic vs. revolver cartridges==
Most [[revolver]] cartridges are rimmed at the base of the case, which seats against the edge of the [[cylinder (firearms)|cylinder]] [[chamber (firearms)|chamber]] to provide [[headspace (firearms)|headspace]] control (to keep the cartridge from moving too far forward into the chamber) and to facilitate easy extraction.

Nearly every [[centerfire]] [[semi-automatic pistol]] cartridge is "rimless", where the rim is of the same diameter as the case body but separated by a circumferential groove in between, into which the [[extractor (firearms)|extractor]] engages the rim by hooking. A "semi-rimmed" cartridge is essentially a rimless one but the rim diameter is slightly larger than the case body, and a "rebated rimless" cartridge is one with the rim smaller in diameter. All such cartridges' headspace on the case mouth (although some, such as [[.38 Super]], at one time seated on the rim, this was changed for accuracy reasons), which prevents the round from entering too far into the chamber. Some cartridges have a rim that is significantly smaller than the case body diameter. These are known as rebated-rim designs and almost always allow a handgun to fire multiple caliber cartridges with only a barrel and [[magazine (firearms)|magazine]] change.
<gallery mode="packed">
File:380 ACP - FMJ - SB - 2.jpg|Rimless [[.380 ACP]] semi-automatic cartridge
File:38 Special - FMJ - SB - 2.jpg|Rimmed [[.38 special]] revolver cartridge
</gallery>

==Projectile designs==
[[File:Shotgun-shot-sequence-1g.jpg|right|thumb|Slow motion shots (1/1,000,000-second exposures) showing shots and [[wadding]] separation after firing from a shotgun.]]
[[Image:Brenneke.jpg|thumb|right|A 12-gauge Brenneke slug]]
[[File:Bean bag round close up.jpg|thumb|Two views of intact [[bean bag round]] and one view of the projectile]]
[[File:7.7 mm Japanese navy.jpg|right|thumb|A cutaway showing a Japanese Navy 7.7 mm rimmed rounds as fired by the Type 92 and Type 97 machine guns—copies of Vickers and Lewis designs. The round is effectively interchangeable with [[.303 British]].]]
* A [[shotgun shell]] loaded with multiple metallic "shot", which are small, generally spherical projectiles.
* [[Shotgun slug]]: A single solid projectile designed to be fired from a shotgun.
* [[Flexible baton round|Baton round]]: a generally non-lethal projectile fired from a riot gun.
* Bullets
** [[Armor-piercing bullet|Armor-piercing]] (AP): A hard bullet made from steel or tungsten alloys in a pointed shape typically covered by a thin layer of lead and or a copper or brass jacket. The lead and jacket are intended to prevent barrel wear from the hard-core materials. AP bullets are sometimes less effective on unarmored targets than FMJ bullets are. This has to do with the reduced tendency of AP projectiles to yaw (turn sideways after impact).
** [[Full metal jacket bullet|Full metal jacket]] (FMJ): Made with a lead core surrounded by a full covering of brass, copper, or mild steel. These usually offer very little deformation or terminal performance expansion, but will occasionally yaw (turn sideways). Despite the name, an FMJ bullet typically has an exposed lead base, which is not visible in an intact cartridge.
** [[Glaser Safety Slug|Glaser safety slug]]: Copper jackets filled with bird shot and covered by a crimped polymer endcap. Upon impact with flesh, the projectile is supposed to fragment, with the birdshot spreading like a miniature shotgun pattern.
** Jacketed hollow point (JHP): Soon after the invention of the JSP, Woolwich Arsenal in Great Britain experimented with this design even further by forming a hole or cavity in the nose of the bullet while keeping most of the exterior profile intact. These bullets could theoretically deform even faster and expand to a larger diameter than the JSP. In personal defense use, concerns have arisen over whether clothing, especially heavy materials like denim, can clog the cavity of JHP bullets and cause expansion failures.
** Jacketed soft point (JSP): In the late 19th century, the Indian Army at [[Dum-Dum Arsenal]], near Kolkata, developed a variation of the FMJ design where the jacket did not cover the nose of the bullet. The soft lead nose was found to expand in the flesh while the remaining jacket still prevented lead fouling in the barrel. The JSP roughly splits the difference between FMJ and JHP. It gives more penetration than JHP but has better terminal ballistic characteristics than the FMJ.
** Round nose lead (RNL): An unjacketed lead bullet. Although largely supplanted by jacketed ammunition, this is still common for older revolver cartridges. Some hunters prefer roundnose ammunition for hunting in brush because they erroneously believe that such a bullet deflects less than sharp-nosed [[spitzer (bullet)|spitzer bullets]], regardless of the fact that this belief has been repeatedly proven not to be true. Refer to American Rifleman magazine.
** Flat nose lead (FNL): Similar to round nose lead, with a flattened nose. Common in [[Cowboy Action Shooting|cowboy action shooting]] and plinking ammunition loads.
** Total metal jacket (TMJ): Featured in some Speer cartridges, the TMJ bullet has a lead core completely and seamlessly enclosed in brass, copper or other jacket metal, including the base. According to Speer's literature, this prevents hot propellant gases from vaporizing lead from the base of the bullet, reducing lead emissions. [[Sellier & Bellot]] produce a similar version that they call TFMJ, with a separate end cap of jacket material.
** Wadcutter (WC): Similar to the FNL, but completely cylindrical, in some instances with a slight concavity in the nose. This bullet derives its name from its popularity for target shooting, because the form factor cuts neat holes in paper targets, making scoring easier and more accurate and because it typically cuts a larger hole than a round nose bullet, a hit centered at the same spot can touch the next smaller ring and therefore score higher.
** Semi-wadcutter (SWC) identical to the WC with a smaller diameter flap pointed conical or radiused nose added. Has the same advantages for target shooters but is easier to load into the gun and works more reliably in semi-automatic guns. This design is also superior for some hunting applications.
** Truncated cone: Also known as round nose flat point, etc. Descriptive of typical modern commercial cast bullet designs.

The [[Hague Conventions of 1899 and 1907|Hague Convention of 1899]] bans the use of expanding projectiles against the military forces of other nations. Some countries accept this as a blanket ban against the use of expanding projectiles against anyone, while others<ref group="note">The US did not sign the complete Hague Convention of 1899 in any case, but still follows its guidelines in military conflicts.</ref> use JSP and HP against non-military forces such as terrorists and criminals.<ref>{{Cite web |url=http://www.sfbg.com/politics/2013/02/20/why-do-cops-use-hollow-point-bullets |title=San Francisco cops use hollow point bullets |access-date=18 December 2013 |archive-url=https://web.archive.org/web/20131219023753/http://www.sfbg.com/politics/2013/02/20/why-do-cops-use-hollow-point-bullets |archive-date=19 December 2013 |url-status=live }}</ref>

==Common cartridges==
[[File:Handguncalibercomparison.jpg|right|thumb|A variety of common pistol cartridges. From left to right: [[22 LR]], [[.22 WMR]], [[5.7×28mm]], [[25 ACP]], [[7.62×25mm Tokarev]], [[32 ACP]], [[380 ACP]], [[9×19mm Parabellum]], [[357 SIG]], [[40 S&W]], [[45 GAP]], [[45 ACP]], [[.38 Special]], [[357 Magnum]], [[45 Colt]]]]

{{Main|Table of handgun and rifle cartridges by year}}
Ammunition types are listed numerically.
* [[.22 Long Rifle]] (22 LR): A round that is often used for target shooting and the hunting of small game such as squirrels. Because of the small size of this round, the smallest self-defence handguns chambered in 22 rimfire (though less effective than most centrefire handguns cartridges) can be concealed in situations where a handgun chambered for a centerfire cartridge could not. The .22 LR is the most commonly fired sporting arms cartridge, primarily because, when compared to any centerfire ammunition, .22 LR ammunition is much less expensive and because recoil generated by the light .22 bullet at modest velocity is very mild.
* [[.22-250 Remington]]: A very popular round for medium to long range small game and varmint hunting, pest control, and target shooting. The 22–250 is one of the most popular rounds for fox hunting and other pest control in Western Europe due to its flat trajectory and very good accuracy on rabbit to fox-sized pests.
* [[.300 Winchester Magnum]]: One of the most popular big game hunting rounds of all time. Also, as a long-range sniping round, it is favored by [[United States Navy SEALs|US Navy SEALs]] and the German [[Bundeswehr]]. While not in the same class as the [[.338 Lapua Magnum]], it has roughly the same power as [[7 mm Remington Magnum]], and easily exceeds the performance of [[7.62×51 mm NATO]].
* [[.30-06 Springfield]] (7.62×63 mm): The standard US Army rifle round for the first half of the 20th century. It is a full-power rifle round suitable for hunting most North American game and most big game worldwide.<ref>{{cite book
 | last1 =Hatcher
 | first1 =Julian
 | last2 =Barr
 | first2 =Al
 | last3 =Neuman
 | first3 =Charles L.
 | title =Reloading Information
 | publisher=[[National Rifle Association of America]]
 | volume =1
 | year =1951
 | location =Washington, D.C.
 | pages =71–78
 }}</ref>
* [[.303 British]]: the standard [[British Empire]] military rifle cartridge from 1888 to 1954.<ref>{{cite book
 | last1 =Barr
 | first1 =Al
 | last2 =Teesdale
 | first2 =Jerald
 | last3 =Keith
 | first3 =Elmer
 | last4 =Hardaway
 | first4 =Ben F.
 | title =Reloading Information
 | publisher=[[National Rifle Association of America]]
 | volume =2
 | year =1951
 | location =Washington, D.C.
 | pages =51&52
 }}</ref>
* [[.308 Winchester]]: the commercial name of a centerfire cartridge based on the military [[7.62×51 mm NATO]] round. Two years prior to the NATO adoption of the 7.62×51 mm NATO T65 in 1954, Winchester (a subsidiary of the Olin Corporation) branded the round and introduced it to the commercial hunting market as the .308 Winchester. The Winchester Model 70 and Model 88 rifles were subsequently chambered for this round. Since then, the 308 Winchester has become the most popular short-action big-game hunting round worldwide. It is also commonly used for civilian and military target events, military sniping, and police sharpshooting.
* [[.357 Magnum]]: Using a lengthened version of the [[.38 Special]] case that was loaded to about twice the maximum chamber pressure of the.38 Special and was rapidly accepted for use by hunters and law enforcement officers. At the time of its introduction, .357 Magnum bullets were claimed to easily pierce the steel body panels of automobiles and crack engine blocks (to disable the vehicle).<ref>{{cite book
 | last1 =Barr
 | first1 =Al
 | last2 =Teesdale
 | first2 =Jerald
 | last3 =Keith
 | first3 =Elmer
 | last4 =Hardaway
 | first4 =Ben F.
 | title =Reloading Information
 | publisher=[[National Rifle Association of America]]
 | volume =2
 | year =1951
 | location =Washington, D.C.
 | pages =77–83
 }}</ref>
* [[.375 Holland & Holland Magnum]]: designed for hunting African big game in the early 20th century and legislated as the minimum diameter rifle caliber for African big game hunting during the mid-20th century<ref name=AH375HNH>{{cite web|last=Gunyana |title=Classic African Cartridges Part X – The .375 H&H Magnum |url=http://www.huntnetwork.net/modules/wfsection/html/Ahclassic%20African%20Cartridge%20Pt10.pdf |work=African Hunter Magazine |publisher=African Hunter |access-date=23 June 2013 |url-status=dead |archive-url=https://web.archive.org/web/20120225044443/https://www.huntnetwork.net/modules/wfsection/html/Ahclassic%20African%20Cartridge%20Pt10.pdf |archive-date=25 February 2012}}</ref>
* [[.40 S&W]]: A shorter-cased version of the [[10mm Auto]].
* [[.44 Magnum]]: A high-powered pistol round designed primarily for hunting.
* [[.45 ACP]]: The standard US pistol round for about 75 years. Typical .45 ACP loads are subsonic.<ref>{{cite book
 | last1 =Hatcher
 | first1 =Julian
 | last2 =Barr
 | first2 =Al
 | last3 =Neuman
 | first3 =Charles L.
 | title =Reloading Information
 | publisher=[[National Rifle Association of America]]
 | volume =1
 | year =1951
 | location =Washington, D.C.
 | pages =93–97
 }}</ref>
* [[.45 Colt]]: a more powerful 45-calibre revolver round using a longer cartridge. The .45 Colt was designed for the [[Colt Single Action Army]] and adopted by the US Army in 1873. Other 45-calibre single-action and double-action revolvers also use this round.
* [[.45-70 Government]]: Adopted by the US Army in 1873 as their standard service rifle cartridge for the [[Springfield Model 1873]] rifle. Most commercial loadings of this cartridge are constrained by the possibility that someone might attempt to fire a modern loading in a vintage rifle or replica. However, current production rifles from Marlin, Ruger, and Browning can accept loads that generate nearly twice the pressure generated by the original black powder cartridges.
* [[.50 BMG]] (12.7×99 mm NATO): Originally designed to destroy aircraft in the First World War,<ref>{{Citation |last=Chinn |first=George M. |title=The Machine Gun: History, Evolution and Development of Manually Operated, Full Automatic, and Power Driven Aircraft Machine Guns |year=1951 |volume=1 |publisher=Department of the Navy, Bureau of Ordnance }}, p. 333</ref> this round still serves an anti-materiel round against light armor. It is used in heavy machine guns and high-powered sniper rifles. Such rifles can be used, amongst other things, for destroying military [[matériel]] such as sensitive parts of grounded aircraft and armored transports. Civilian shooters use these for long-distance target shooting.
* [[5.45×39 mm]] Soviet: The Soviet adaptation of the [[5.56×45 mm NATO]] round.
* [[5.56×45 mm NATO]]: Adopted by the US military in the 1960s, it later became the NATO standard rifle round in the early 1980s, displacing the [[7.62×51 mm]]. Remington later adopted this military round as the [[.223 Remington]], a very popular round for small game hunting.
* [[7×64 mm]]: One of the most popular long-range game hunting rounds in Europe, especially in the countries such as France and (formerly) Belgium where the possession of firearms chambered for a (former) military round is forbidden or is more heavily restricted. This round is offered by European rifle makers in both bolt-action rifles and a rimmed version. The 7×65 mmR is chambered in double and combination rifles. Another reason for its popularity is its flat trajectory, very good penetration, and high versatility, depending on what bullet and load are used. Combined with a large choice of different 7&nbsp;mm bullets available the 7×64mm is used on everything from fox and [[geese]] to [[red deer]], Scandinavian [[moose]] and European [[brown bear]] equivalent to the North American black bear. The 7×64mm essentially duplicates the performance of the 270 Winchester and 280 Remington.
* [[7 mm Remington Magnum]]: A long-range hunting round.
* [[7.62×39mm]]: The standard Soviet/ComBloc rifle round from the mid-1940s to the mid-1970s, this is easily one of the most widely distributed rounds in the world due to the distribution of the ubiquitous [[Mikhail Kalashnikov|Kalashnikov]] [[AK-47]] series.
* [[7.62×51mm NATO]]: This was the standard NATO rifle round until its replacement by the 5.56×45mm. It is currently the standard NATO sniper rifle and medium machinegun chambering. In the 1950s, it was the standard NATO round for rifles, but recoil and weight proved problematic for the new [[battle rifle]] designs such as the [[FN FAL]]. Standardized commercially as the 308 Winchester.
* [[7.62×54mmR]]: The standard Russian rifle round from the 1890s to the mid-1940s. The "R" stands for rimmed. The 7.62×54mmR rifle round is a Russian design dating back to 1891. Originally designed for the Mosin-Nagant rifle, it was used during the late Tsarist era and throughout the Soviet period, in machine guns and rifles such as the SVT-40. The Winchester Model 1895 was also chambered for this cartridge per contract with the Russian government. It is still in use by the Russian military in the Dragunov and other sniper rifles and some machine guns. The round is colloquially known as the "7.62 Russian". This name sometimes causes people to confuse this round with the "7.62 Soviet" round, which refers to the 7.62&nbsp;×&nbsp;39 round used in the SKS and AK-47 rifles.
* [[32 ACP|7.65×17mm Browning SR]] (32 ACP): A very small pistol round. However, this was the predominant Police Service round in Europe until the mid-1970s. The "SR" stands for semi-rimmed, meaning the case rim is slightly larger than the case body diameter.
* [[7.92×57mm Mauser|8×57mm IS]]: The standard German service rifle round from 1888 to 1945, the 8×57mmIS (aka 8&nbsp;mm Mauser) has seen wide distribution around the globe through commercial, surplus, and military sales, and is still a popular and commonly used hunting round in most of Europe, partly because of the abundance of affordable hunting rifles in this chambering as well as a broad availability of different hunting, target, and military surplus ammunition available.<ref>{{cite book
 | last1 =Hatcher
 | first1 =Julian
 | last2 =Barr
 | first2 =Al
 | last3 =Neuman
 | first3 =Charles L.
 | title =Reloading Information
 | publisher=[[National Rifle Association of America]]
 | volume =1
 | year =1951
 | location =Washington, D.C.
 | pages =79–84
 }}</ref>
* [[9×19mm Parabellum]]: Invented for the German military at the turn of the 20th century, the wide distribution of the 9×19mm Parabellum round made it the logical choice for the NATO standard pistol and [[Submachine gun]] round.
* [[9.3×62mm]]: Very common big game hunting round in Scandinavia along with the [[6.5×55mm]], where it is used as a very versatile hunting round on anything from small and medium game with lightweight cast lead bullets to the largest European big game with heavy soft point hunting bullets. The 9.3×62mm is also very popular in the rest of Europe for Big game, especially driven Big game hunts due to its effective stopping power on running game. And, it is the single round smaller than the 375 H&H Magnum that has routinely been allowed for legal hunting of dangerous African species.
* [[12.7×108mm]]: The 12.7×108mm round is a heavy machine gun and anti-materiel rifle round used by the Soviet Union, the former Warsaw Pact, modern Russia, and other countries. It is the approximate Russian equivalent of the NATO .50 BMG (12.7×99mm NATO) round. The differences between the two are the bullet shape, the types of powder used, and that the case of the 12.7×108mm is 9&nbsp;mm longer and marginally more powerful.
* [[14.5×114mm]]: The 14.5×114&nbsp;mm is a heavy machine gun and anti-materiel rifle round used by the Soviet Union, the former Warsaw Pact, modern Russia, and other countries. Its most common use is in the [[KPV heavy machine gun]] found on several Russian Military vehicles.

===Snake shot===
[[File:.22LR ratshot.jpg|thumb|upright=.5|CCI .22LR snake shot loaded with No. 12 shot]]
{{Main|Snake shot}}

''Snake shot'' (AKA: ''bird shot'', ''rat shot'' and ''dust shot'')<ref>{{Cite book|url=https://archive.org/stream/guidetotaxidermy00reed#page/22/mode/2up/|title=Guide to taxidermy|pages=22–23|author=Reed, C.K. & C.A. Reed|year=1914|access-date=5 August 2018|archive-url=https://web.archive.org/web/20160320164421/http://archive.org/stream/guidetotaxidermy00reed#page/22/mode/2up/|archive-date=20 March 2016|url-status=live}}</ref> refers to handgun and rifle rounds loaded with small [[lead shot]]. Snake shot is generally used for shooting at snakes, rodents, birds, and other [[Pest (organism)|pests]] at very close range.

The most common snake shot cartridge is [[.22 Long Rifle]] loaded with No. 12 shot. From a standard rifle these can produce effective patterns only to a distance of about {{convert|3|m|ft|-1}} – but in a smoothbore shotgun this can extend as far as {{convert|15|m|ft|-1}}.

===Caseless ammunition===
{{Main|Caseless ammunition}}
[[File:4.73x33 Caseless-crop.jpg|thumb|left|An example of caseless ammunition. This disassembled round, the 4.73×33mm, is used in the [[Heckler & Koch G11]] rifle.]]

Many governments and companies continue to develop caseless ammunition {{Citation needed|date=April 2014}} (where the entire case assembly is either consumed when the round fires or whatever remains is ejected with the bullet). So far, none has been successful enough to reach the civilian market and gain commercial success. Even within the military market, use is limited. Around 1848, [[Sharps Rifle Manufacturing Company|Sharps]] introduced a rifle and paper cartridge (containing everything but the primer) system. When new, these guns had significant gas leaks at the chamber end, and with use these leaks progressively worsened. This problem plagues caseless cartridges and gun systems to this day.

The [[Daisy V/L|Daisy Heddon VL Single Shot Rifle]], which used a caseless round in .22 caliber, was produced by the air gun company, beginning in 1968. Apparently, Daisy never considered the gun an actual firearm. In 1969, the ATF ruled it was in fact a firearm, which Daisy was not licensed to produce. Production of the guns and the ammo was discontinued in 1969. They are still available on the secondary market, mainly as collector items, as most owners report that accuracy is not very good.<ref>{{Cite web |url=http://everything2.com/title/Daisy+V%252FL |title=Daisy V/L |access-date=3 October 2013 |archive-url=https://web.archive.org/web/20131005223625/http://everything2.com/title/Daisy+V%252FL |archive-date=5 October 2013 |url-status=live }}</ref>

In 1989, [[Heckler & Koch]], a prominent German firearms manufacturer, began advertising the [[G11 assault rifle]], which shot a 4.73×33 square caseless round. The round was mechanically fired, with an integral primer.{{Citation needed|date=June 2011}}

In 1993 [[Voere]] of Austria began selling a gun and caseless ammunition. Their system used a primer, [[electronic firing|electronically fired]] at 17.5 ± 2 [[volt]]s. The upper and lower limits prevent fire from either stray currents or [[static electricity]]. The direct electrical firing eliminates the mechanical delays associated with a striker, reducing [[lock time]] and allowing for easier adjustment of the rifle trigger.{{Citation needed|date=June 2011}}

In both instances, the "case" was molded directly from solid [[nitrocellulose]], which is itself relatively strong and inert. The bullet and primer were glued into the propellant block.{{Citation needed|date=June 2011}}

===Trounds===
[[File:Dardick 1500 with trounds (29432934078).jpg|thumb|Dardick 1500 with Trounds]]
{{Main|Dardick tround}}
The "Tround" ("Triangular Round") was a unique type of cartridge designed in 1958 by David Dardick, for use in specially designed Dardick 1100 and Dardick 1500 open-chamber firearms. As their name suggests, Trounds were triangular in cross-section and were made of plastic or aluminum, with the cartridge completely encasing the powder and projectile. The Tround design was also produced as a cartridge adaptor, to allow conventional [[.38 Special]] and [[22 Long Rifle]] cartridges to be used with the Dardick firearms.{{Citation needed|date=June 2011}}

===Eco-friendly cartridges===
They are meant to prevent pollution and are mostly biodegradable (metals being the exception) or fully. They are also meant to be used on older guns.<ref>{{Cite web|url=https://www.scribehound.com/cartridges/s/non-toxic-shotgun-cartridges/are-these-the-most-eco-friendly-cartridges-on-the-market?ref=related|title=GunsOnPegs|access-date=6 February 2023|archive-date=6 February 2023|archive-url=https://web.archive.org/web/20230206174504/https://www.scribehound.com/cartridges/s/non-toxic-shotgun-cartridges/are-these-the-most-eco-friendly-cartridges-on-the-market?ref=related|url-status=live}}</ref>

==Blank ammunition==
{{Main|Blank (cartridge)}}
[[File:Platzpatronen762 9.jpg|thumb|Blank cartridges:{{unordered list
 | [[7.62×51mm NATO]] (left)
 | [[9×19mm Parabellum]] (right).}}]]
A blank is a charged cartridge that does not contain a projectile or alternatively uses a non-metallic (for instance, wooden) projectile that pulverizes when hitting a blank firing adapter. To contain the propellant, the opening where the projectile would normally be located is crimped shut, and/or it is sealed with some material that disperses rapidly upon leaving the barrel.

This sealing material can still potentially cause harm at extremely close range. Actor [[Jon-Erik Hexum#Death|Jon-Erik Hexum]] died when he shot himself in the head with a blank, and actor [[Brandon Lee]] was famously killed during the filming of ''[[The Crow (1994 film)|The Crow]]'' when a blank fired behind a bullet that was stuck in the bore drove that bullet through his abdomen and into his spine. The gun had not been properly deactivated and a primed case with a bullet instead of a dummy had been used previously. Someone pulled the trigger and the primer drove the bullet silently into the bore.

Blanks are used in training, but do not always cause a gun to behave the same as live ammunition does; recoil is always far weaker, and some automatic guns only cycle correctly when the gun is fitted with a [[blank-firing adaptor]] to confine gas pressure within the barrel to operate the gas system.

Blanks can also be used to launch a [[rifle grenade]], although later systems used a "bullet trap" design that captures a bullet from a conventional round, speeding deployment. This also negates the risk of mistakenly firing a live bullet into the rifle grenade, causing it to instantly explode instead of propelling it forward.

Blanks are also used as dedicated launchers for propelling a [[grappling hook]], rope line or flare, or for a training lure for training [[gun dog]]s.

The power loads used in a variety of [[nail gun]]s are essentially rimfire blanks.{{Citation needed|date=June 2011}}

==Dummy rounds==
[[File:Naboj23 mm.jpg|thumb|left|80px|[[23×152mm]] cartridge, drill round]]
{{Main|Dummy round}}
Drill rounds are inert versions of cartridges used for education and practice during military training. Other than the lack of propellant and primer, these are the same size as normal cartridges and will fit into the mechanism of a gun in the same way as a live cartridge does. Because dry-firing (releasing the firing pin with an empty chamber) a gun can sometimes lead to firing pin (striker) damage, dummy rounds termed [[snap cap]]s are designed to protect centerfire guns from possible damage during "dry-fire" trigger control practices.

To distinguish drill rounds and snap-caps from live rounds these are marked distinctively. Several forms of markings are used; e.g. setting colored flutes in the case, drilling holes through the case, coloring the bullet or cartridge, or a combination of these. In the case of centerfire drill rounds, the primer will often be absent, its mounting hole in the base is left open. Because these are mechanically identical to live rounds, which are intended to be loaded once, fired, and then discarded, drill rounds have a tendency to become significantly worn and damaged with repeated passage through [[Magazine (firearms)|magazine]]s and firing mechanisms, and must be frequently inspected to ensure that these are not so degraded as to be unusable. For example, the cases can become torn or misshapen and snag on moving parts, or the bullet can become separated and stay in the breech when the case is ejected.{{Citation needed|date=June 2011}}

=== ECI (Empty chamber indicator) ===
[[File:Mek-Porek 9x19mm Parabellum from behind.jpg|thumb|upright|9 × 19 mm Mek-Porek]]
The brightly colored ECI is an inert cartridge base designed to prevent a live round from being unintentionally chambered, to reduce the chances of an accidental discharge from mechanical or operator failure. An L-shaped flag is visible from the outside so that the shooter and other people concerned are instantly aware of the situation of the weapon. The ECI is usually tethered to its weapon by a short string and can be quickly ejected to make way for a live round if the situation suddenly warrants it. This safety device is standard-issue in the [[Israel Defense Forces]]<ref>Shoval, Lilach. [http://www.israelhayom.com/site/newsletter_article.php?id=15149 "IDF to issue new safety device to prevent accidental weapon discharge"] {{Webarchive|url=https://web.archive.org/web/20160104203837/http://www.israelhayom.com/site/newsletter_article.php?id=15149 |date=4 January 2016 }}, ''[[Israel Hayom]]'', Tel Aviv, 31 January 2014. Retrieved on 4 January 2016.</ref> known as {{ill|מ"ק פורק|he|מ"ק_פורק|vertical-align=sup}} ("Mek-Porek").

===Snap cap===
[[File:Snap caps.jpg|left|thumb|An assortment of snap caps of varying calibers]]
A [[snap cap]] is a device that is shaped like a standard cartridge but contains no primer, propellant, or projectile.  It is used to ensure that [[dry firing]] firearms of certain designs does not cause damage.  A small number of rimfire and centerfire firearms of older design should not be test-fired with the chamber empty, as this can lead to weakening or breakage of the firing pin and increased wear to other components in those firearms. In the instance of a rimfire weapon of primitive design, dry firing can also cause deformation of the chamber edge.  For this reason, some shooters use a snap cap in an attempt to cushion the weapon's firing pin as it moves forward.  Some snap caps contain a spring-dampened fake primer, or one made of plastic, or none at all; the springs or plastic absorb force from the firing pin, allowing the user to safely test the function of the [[firearm action]] without damaging its components.

Snap caps and action-proving dummy rounds also work as a training tool to replace live rounds for loading and unloading drills, as well as training for misfires or other malfunctions, as they function identically to a live "dud" round that has not ignited.  Usually, one snap-cap is usable for 300 to 400 clicks.{{Citation needed|date=October 2023}}  After that, due to the hole at the false primer, the firing pin does not reach it.

==See also==
<!-- Please respect alphabetical order -->
* [[Ammunition box]]
* [[Antique firearms]]
* [[List of handgun cartridges]]
* [[List of Magnum cartridges]]
* [[List of rebated-rim cartridges]]
* [[List of rifle cartridges]]
* [[Table of handgun and rifle cartridges]]

==Notes==
{{Reflist|group=note}}

==References==
{{Reflist|30em}}

==External links==
{{Commons category|Ammunition cartridges}}
* [http://www.cartridgecollectors.org/glossary.htm Cartridge Collectors]
* [http://www.rawles.to/Euro_Box_FAQ.html European Ammunition Box Translations]
* [https://apps.dtic.mil/sti/tr/pdf/ADA433982.pdf ARMAMENT RESEARCH DEVELOPMENT AND ENGINEERING CENTER - Enhanced Propellant and Cartridge Case Designs]

{{Firearms}}
{{Authority control}}

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[[Category:Ammunition]]
[[Category:Pistol and rifle cartridges| ]]