Editing .45 Colt (section)

==Cartridge loads==
The .45 Colt originally was a [[Black powder|black-powder]] cartridge, but modern loadings use [[smokeless powder]]. The original black-powder loads called for {{convert|40|gr}} of black powder behind an Ogival & flat nosed {{convert|255|gr|g|adj=on}} lead bullet. These loads developed muzzle velocities of {{convert|1050|ft/s|m/s|abbr=on}}. However, this load generated too much recoil for the average soldier and was, after a few years, reduced to {{convert|28|gr|g|abbr=on}} of black powder yielding {{convert|855|ft/s|m/s|abbr=on}} in Army tests. Then, the introduction of the Schofield revolver with its shorter cylinder, quick loading "Top-Break" frame, and chambered in [[.45 Schofield]] caused a problem for the Supply Corps in that they now had to supply two different types of .45 Caliber revolver ammunition. Further troubles were caused by the fact that the Schofield cartridge rim was too wide to load into adjacent chambers in the colt cylinder, turning the Colt into a three shooter (being able to only place a round in every other chamber), if the wrong ammunition was sent to that particular outpost. So, the Army came up with a short case narrow rim cartridge that only held {{convert|26|gr|g|abbr=on}} of black powder that could be used in both revolvers. That load gave about {{convert|760|ft/s|m/s|abbr=on}} with a {{convert|250|gr|g|abbr=on}} bullet out of the Schofield revolver with its shorter barrel.<ref name="fn2">{{cite journal|last=Taffin|first=John|author-link=John Taffin|date=July 2001|title=The Custom Loading .45 Colt|url=http://www.findarticles.com/p/articles/mi_m0BQY/is_7_47/ai_75287317|url-status=dead|journal=[[Guns (magazine)|Guns]]|archive-url=https://web.archive.org/web/20070826112140/http://www.findarticles.com/p/articles/mi_m0BQY/is_7_47/ai_75287317|archive-date=August 26, 2007|access-date=February 14, 2011}}</ref> Because of the power of the {{convert|40|gr|g|abbr=on}} of black powder and its excellent accuracy, the .45 Colt was known as a sure man stopper and horse killer. It became the most-used cartridge at the time of its introduction, succeeding the [[.44-40 Winchester]].

The .45 Colt at that time did not enjoy the .44-40's advantage of a Winchester rifle chambered for it being available, thus allowing the use of the same cartridge in both a pistol and a rifle.<ref name = vent>{{cite journal |last=Venturino |first=Mike |author-link=Mike Venturino |date=1998 |title=Slingin' Lead |journal=Popular Mechanics |publisher=Jay McGill |volume=175 |issue=4 |pages=76–79}}</ref> According to rumor at the time, this was owing to early .45 Colt cartridges having a very narrow rim that caused ejection issues from a rifle chamber. Today, modern Winchesters, Marlins, and other replicas have remedied this omission almost 50 years after the fact, and .45 Colt is now available in modern [[lever-action]] rifles.

While this aforementioned rumor has been one of the numerous arguments used to explain the lack of a rifle chambered in .45 Colt, it may have simply been a case of Colt refusing to authorize the use of their patented .45 Colt cartridge in other manufacturers’ arms. Only after the expiration of Colt's original patents for the .45 Colt did it become available in a rifle.<ref name = vent/> This, however, does not explain the absence of a .45 Colt chambering (or indeed any of Colt's own cartridges) in the Colt-Burgess lever-action or Colt Lightning slide-action rifles. Thus lending more credence to the rumored basic problem with Colt's revolver cartridges when used in rifles. (The modern .45 Colt cartridge rim is still narrow, but features an extractor groove cut into the base of the case, a feature common to most modern cartridges but not at all common in the late 19th century.)

The U.S. Army's .45 Colt round used in its [[Colt New Service|M1909 revolver]], which had a barrel of {{convert|5.5|in}}, fired a {{convert|250|gr|adj=on}} bullet at a muzzle velocity of {{cvt|738|ft/s}}, giving a muzzle energy of {{cvt|297|ftlbf}}.<ref>{{cite book |author1=U.S. Army Ordnance Department |author-link1=United States Army Ordnance Corps |title=Description of the Colt's Double-Action Revolver, Caliber .45, Model of 1909, with Rules for Management, Memoranda of Trajectory, and Description of Ammunition |date=1917 |publisher=[[United States Government Publishing Office|U.S. Government Printing Office]] |location=Washington |url=https://archive.org/details/coltrevolver00unitrich}} Page 11 and plate V.</ref> Today's standard factory loads develop around {{convert|400|ftlbf|J|abbr=on}} of [[Firearm muzzle|muzzle]] energy at about {{convert|860|ft/s|m/s|abbr=on}}, making it roughly equivalent to modern [[.45 ACP]] loads. There are [[Cowboy action shooting|Cowboy Action Shooting]] loads which develop muzzle velocities of around {{convert|750|ft/s|m/s|abbr=on}}.

''Cartridges of the World'' states that .45 Colt should never be loaded to more than {{convert|800|ft/s|m/s|abbr=on}} in blackpowder revolvers.<ref name="COTW14">{{cite book|title=Cartridges of the World|date=2014|publisher=Krause Publishing|location=Iola, WI |isbn=978-1-4402-4265-6 |edition=14th}}</ref>

===High pressure ammunition===
Some handloads and factory-manufactured cartridges put this round in the same class as the [[.44 Magnum]], using specially made revolvers.<ref name="COTW14" /><ref>{{cite journal |last=Taffin |first=John |date=2010 |title=Big and heavy |journal=American Handgunner |url=http://findarticles.com/p/articles/mi_m0BTT/is_3_34/ai_n56208962/}}</ref> These loads cannot be used in any original Colt Single Action Army or replica thereof, such as those produced by [[A. Uberti, Srl.|Uberti]], [[Beretta]], the [[Taurus (manufacturer)|Taurus Gaucho]], or the [[Ruger|Ruger New Vaquero]], as these guns are built on the smaller frame with thinner cylinder walls. These loads should be used only in modern large-frame revolvers such as the [[Ruger Blackhawk]], [[Ruger Redhawk]], and the original large frame [[Ruger Vaquero]] (sometimes referred to as the "Old Model" to differentiate it from the small frame "New Vaquero.")

[[Thompson Center Arms|Thompson Center Contender]] "Magnum" .45 Colt loadings can also be safely fired from any gun chambered in either the [[.454 Casull]] or [[.460 S&W Magnum]] cartridges, though proper feeding may be an issue in repeating rifles chambered for either .454 Casull or .460 S&W Magnum as the [[Overall length|OAL]] is significantly shorter. Modern rifles with strong actions (such as the [[Winchester Model 1894]], [[Marlin Model 1894]], and new replicas of the [[Winchester Model 1892]]) chambered for the cartridge can safely handle the heavier loadings.

===Handloading===
Colt .45 revolvers made until early WWII had barrels with .454" groove diameters. After WWII diameters of .451–.452" were produced. Using .454" diameter bullets in the smaller barrels will work but will generate higher pressures. Cases used with .454" bullets may have to be full-length resized to work in newer guns.<ref name="Speer No. 10">{{cite book|title=Reloading Manual No. 10|date=1979|publisher=Speer - Omark Industries|location=Lewiston, ID}}</ref> Speer handloading guidance states that the loads they show should be used only in handguns made specifically for modern smokeless powder. The loads mentioned in No. 10 reloading manual state that they do not exceed {{convert|15,000|psi|MPa|abbr=on}}. This is the equivalent of +P loading as normal pressure for the .45 Colt is {{convert|14,000|psi|MPa|abbr=on}}.<ref name="Speer No. 10" />

In a section specifically titled '''"45 Colt for Ruger or Contender only"''' Speer makes reference to velocities up to {{convert|1,300|ft/s|m/s|abbr=on}} with {{convert|200|gr|g|abbr=on}} bullets. They also state that pressures do not exceed {{convert|25,000|psi|MPa|abbr=on}} (CUP). This is well beyond a pressure that can destroy even modern guns chambered in .45 Colt with the exception of the large frame Ruger Blackhawk, Ruger Redhawk, Freedom Arms Models 83 and 97, and Dan Wesson revolvers.<ref name="Speer No. 10" />