Editing Revolver (section)

== Design ==
[[File:Revolver modèle 1882 IMG 3070.jpg|thumb|left|Details of a [[Schmidt M1882]], showing the hammer, chambers for the ammunition in the cylinder, and the mechanism to rotate the cylinder. Revolver of the Gendarmerie of [[Vaud]], on display at [[Morges]] castle museum]]

A revolver has several firing chambers arranged in a circle in a cylindrical block; one at a time, these chambers are brought into alignment with the firing mechanism and barrel. In contrast, other repeating firearms, such as [[bolt-action]], [[lever-action]], [[pump-action]], and [[Semi-automatic firearm|semi-automatic]], have a single firing chamber and a mechanism to load and extract cartridges into it.<ref name="forensic">{{cite book|last1=Tilstone|first1=William J.|last2=Savage|first2=Kathleen A.|last3=Clark|first3=Leigh A.|title=Forensic Science: An Encyclopedia of History, Methods, and Techniques|url=https://books.google.com/books?id=zIRQOssWbaoC&pg=PA158|date=1 January 2006|publisher=ABC-CLIO|isbn=978-1-57607-194-6|pages=158–159|access-date=12 November 2015|archive-date=22 April 2023|archive-url=https://web.archive.org/web/20230422232156/https://books.google.com/books?id=zIRQOssWbaoC&pg=PA158|url-status=live}}</ref>

A single-action revolver requires the hammer to be pulled back by hand before each shot, which also revolves the cylinder. This leaves the trigger with one "single action" to perform—releasing the hammer to fire the shot. In contrast, with a self-cocking, or double-action, revolver, one long squeeze of the trigger pulls back the hammer and revolves the cylinder, then finally fires the shot, thus requiring more force and distance to pull the trigger than in a single-action revolver. They can generally be fired faster than a single-action, but with reduced accuracy in the hands of most shooters.<ref name="forensic" />

Most modern revolvers are "traditional double-action", which means they may operate either in single-action or self-cocking mode. The accepted meaning of "double-action" has come to be the same as "self-cocking", so modern revolvers that cannot be pre-cocked are called "double-action-only".<ref name="forensic" /> These are intended for concealed carry, because the hammer of a traditional design is prone to snagging on clothes when drawn. Most revolvers do not come with [[Picatinny rail|accessory rails]], which are used for mounting [[Tactical light|lights]] and [[Laser aiming module|lasers]], except for the [[Smith & Wesson Model 327|Smith & Wesson M&P R8]] ([[.357 Magnum]]),<ref name="Eckstine2013">{{cite book|last=Eckstine|first=Roger|title=Shooter's Bible Guide to Home Defense: A Comprehensive Handbook on How to Protect Your Property from Intrusion and Invasion|url=https://books.google.com/books?id=5mstAgAAQBAJ&pg=PT253|year=2013|publisher=Skyhorse Publishing Company, Incorporated|isbn=978-1-62873-539-0|page=253}}</ref> Smith & Wesson Model 325 Thunder Ranch ([[.45 ACP]]),<ref name="SupicaNahas2007">{{cite book|last1=Supica|first1=Jim|last2=Nahas|first2=Richard|title=Standard Catalog of Smith & Wesson|url=https://books.google.com/books?id=D8qXdU45SCUC&pg=PA301|date= 2007|publisher=F+W Media, Inc|location=Iola, Wisconsin|isbn=978-0-89689-293-4|page=301}}</ref> and all versions of the [[Chiappa Rhino]] (.357 Magnum, [[9×19mm]], [[.40 S&W]], or [[9×21mm]]) except for the 2" and 3" models, respectively.<ref name="Shideler2010">{{cite book|last=Shideler|first=Dan|title=Guns Illustrated 2011: The Latest Guns, Specs & Prices|url=https://books.google.com/books?id=eT2t8PBVmVMC&pg=PA53|date=2010|publisher=F+W Media, Inc|location=Iola, Wisconsin|isbn=978-1-4402-1624-4|page=53}}</ref> However, certain revolvers, such as the [[Taurus Judge]] and [[Charter Arms]] revolvers, can be fitted with accessory rails.<ref>{{cite book |last=Ayoob |first=Massad |author-link=Massad Ayoob |title=The Gun Digest Book of Combat Handgunnery |url=https://books.google.com/books?id=ZSOkN9sQDdMC&pg=PA233 |edition=Iola, Wisconsin |date=2007 |publisher=Gun Digest Books|isbn=978-1-4402-1825-5 |page=233 }}</ref>

[[File:Iver Johnson revolvers.jpg|thumb|300px|An advertisement for [[Iver Johnson]] revolvers claimed they were safe enough for children to handle.]]

Revolvers most commonly have 6 chambers, hence the common names of "six-gun" or "six-shooter".<ref name="RKCampbell2009" /> However, some revolvers have more or fewer than 6, depending on the size of the gun and [[caliber]] of the bullet. Each chamber has to be reloaded manually, which makes reloading a revolver a much slower procedure than reloading a semi-automatic pistol.<ref name="RKCampbell2009">{{cite book|last=Campbell|first=Robert K.|title=The Gun Digest Book of Personal Protection & Home Defense|url=https://books.google.com/books?id=L7FVmlpWTD8C&pg=PA20|year=2009|publisher=Krause Publications|location=Iola, Wisconsin|isbn=978-1-4402-2443-0|page=20}}</ref>

Compared to autoloading handguns, a revolver is often much simpler to operate and may have greater reliability.<ref name="RKCampbell2009" /> For example, should a semiautomatic pistol fail to fire, clearing the chamber requires manually cycling the action to remove the errant round, as cycling the action normally depends on the energy of a cartridge firing.<ref name="RKCampbell2009" /> With a revolver, this is not necessary as none of the energy for cycling the revolver comes from the firing of the cartridge, but is instead supplied by the user either through cocking the hammer or, in a double-action design, by just squeezing the trigger.<ref name="RKCampbell2009" /> Another significant advantage of revolvers is superior ergonomics, particularly for users with small hands.<ref name="RKCampbell2009" /> A revolver's grip does not hold a magazine, and it can be designed or customized much more than the grip of a typical semi-automatic.<ref name="RKCampbell2009" /> Partially because of these reasons, revolvers still hold significant market share as concealed carry and home-defense weapons.<ref name="RKCampbell2009" />

A revolver can be kept loaded and ready to fire without fatiguing any springs and is not very dependent on lubrication for proper firing.<ref name="RKCampbell2009" /> Additionally, in the case of double-action-only revolvers there is no risk of accidental discharge from dropping alone, as the hammer is cocked by the trigger pull.<ref name="RKCampbell2009" /> However, the revolver's clockwork-like internal parts are relatively delicate and can become misaligned after a severe impact, and its revolving cylinder can become jammed by excessive dirt or debris.<ref name="RKCampbell2009" />

Over the long period of development of the revolver, many calibers have been used.<ref name="Keith1955">{{cite book |last=Keith |first=Elmer |author-link=Elmer Keith |title=Sixguns |date=1955 |publisher=Wolfe Publishing Company |location=Salmon, Idaho |isbn=978-1-879356-09-2 |page=125 }}</ref> Some of these have proved more durable during periods of standardization and some have entered general public awareness. Among these are the [[.22 rimfire|.22 Long Rifle]], a caliber popular for target shooting and teaching novice shooters; .38 Special and .357 Magnum, known for police use; the [[.44 Magnum]], famous from [[Clint Eastwood]]'s ''[[Dirty Harry]]'' films; and the [[.45 Colt]], used in the Colt revolver of the [[Wild West]]. Introduced in 2003, the [[Smith & Wesson Model 500]] is one of the most powerful revolvers, utilizing the [[.500 S&W Magnum]] cartridge.<ref name="Shideler20112">{{cite book |last=Shideler |first=Dan |title=Gun Digest Book of Guns & Prices 2011 |url=https://books.google.com/books?id=YLzs0xmcpYwC&pg=PA583 |date=2011 |publisher=Gun Digest Books |location=Iola, Wisconsin |isbn=978-1-4402-1896-5 |page=583 }}</ref>

Because the rounds in a revolver are [[Headspace (firearms)|headspaced]] on the rim, some revolvers are capable of chambering more than one type of ammunition. Revolvers chambered in [[.44 Magnum]] will also chamber [[.44 Special]] and [[.44 Russian]], likewise revolvers in [[.357 Magnum]] will safely chamber [[.38 Special]], [[.38 Long Colt]], and [[.38 Short Colt]]; while revolvers in [[.22 Winchester Magnum Rimfire|.22 WMR]] can chamber [[.22 Long Rifle]], [[.22 Long]], and [[.22 Short]], it is not safe to do so, due to differences in cartridge pressures and the fact that .22 WMR does not shoot a "heeled" bullet, along with differences in rim diameter that can allow high pressure gases to escape behind the cartridge and seriously injure the user. However, some .22 revolvers come with interchangeable cylinders so that .22 Long Rifle can be shot from a .22 WMR revolver. In 1996, the [[Medusa Model 47]] was made with the ability to chamber 25 different cartridges with bullet diameters between .355" and .357".<ref>{{cite book |last=Shideler |first=Dan |title=The Gun Digest Book of Modern Gun Values: The Shooter's Guide to Guns 1900-Present |url=https://books.google.com/books?id=MWFXRDeFrpsC&pg=PA188 |date=26 June 2009 |publisher=Gun Digest Books |location=Iola |isbn=978-0-89689-824-0 |page=188 }}</ref>

[[File:Perkussions Revolver Le Mat.JPG|thumb|left|The [[LeMat Revolver|LeMat Percussion Revolver]], with 9 revolving chambers firing bullets and a center shotgun barrel firing [[lead shot]], was used by the Confederate troops in the [[American Civil War]].]] 
[[File:Le Mat Revolver.jpg|thumb|left|LeMat Revolver, an unusual pinfire cartridge model]]

Revolver technology is also present in other weapons used by the U.S. military. Some [[Revolver cannon|autocannons]] and [[grenade launcher]]s use mechanisms similar to revolvers, and some [[riot shotgun]]s use spring-loaded cylinders holding up to 12 rounds.<ref>{{cite book |last=Dockery |first=Kevin |author-link=Kevin Dockery (author) |title=Future Weapons |url=https://books.google.com/books?id=8RxJxY7wQn0C&pg=PA289 |date=2007 |location=United States |publisher=Penguin Group |isbn=978-0-425-21750-4 |page=289 }}</ref> In addition to serving as backup guns, revolvers still fill the specialized role as a shield gun; law enforcement personnel using a "bulletproof" [[ballistic shield|gun shield]] sometimes opt for a revolver instead of a self-loading pistol, because the slide of a pistol may strike the front of the shield when fired. Revolvers do not suffer from this disadvantage. A second revolver may be secured behind the shield to provide a quick means of continuity of fire. Many police also still use revolvers as their duty weapon due to their relative mechanical simplicity and ease of use.<ref>{{cite web |last=Taylor |first=Chuck |url=http://www.tactical-life.com/online/exclusives/commentary-why-the-revolver-wont-go-away/ |title=Why the Revolver Won't Go Away |publisher=Tactical-Life.com |date=2009-08-29 |access-date=2009-09-16 |archive-date=2009-08-10 |archive-url=https://web.archive.org/web/20090810230657/http://www.tactical-life.com/online/exclusives/commentary-why-the-revolver-wont-go-away/ |url-status=live }}</ref>

In 2010, major revolver manufacturers started producing polymer frame revolvers like the [[Ruger LCR]], Smith & Wesson Bodyguard 38, and [[Taurus (manufacturer)|Taurus]] Protector Polymer. The new design incorporates polymer technology that lowers weight significantly, helps absorb recoil, and is strong enough to handle .38 Special +P and .357 Magnum loads. The polymer is only used on the lower frame and is joined to an upper frame, barrel, and cylinder that are made of metal alloy. Polymer technology is considered one of the major advancements in revolver history because the frame was previously always metal alloy and mostly a one-piece design.<ref name="Ahern2010">{{cite book|last=Ahern|first=Jerry|title=Gun Digest Buyer's Guide to Concealed-Carry Handguns|url=https://books.google.com/books?id=LyoEmeSwGwgC&pg=PA199|year=2010|publisher=Gun Digest Books|location=Iola, Wisconsin|isbn=978-1-4402-1743-2|pages=199–201}}</ref>

Another 21st century development in revolver technology is the [[Chiappa Rhino]], a revolver introduced by Italian manufacturer [[Chiappa Firearms|Chiappa]] in 2009, and first sold in the U.S. in 2010. The Rhino, built with the U.S. concealed carry market in mind, is designed so that the bullet fires from the bottom chamber of the cylinder instead of the top chamber, as is typical in revolvers. This is intended to reduce [[muzzle flip]], allowing for faster and more accurate repeat shots. In addition, the cylinder cross-section is hexagonal instead of circular, further reducing the weapon's profile.<ref name="Shideler2010" />