. 45 Colt The . 45 Colt cartridge is a handgun cartridge dating to 1872 . It began as a black powder revolver round developed for the Colt Single Action Army revolver , but is offered as a magnum level handgun hunting round in modern usage . This cartridge was adopted by the U . S . Army in 1873 and served as the official US military handgun cartridge for 19 years . It is sometimes , although incorrectly , referred to as . 45 Long Colt or . 45LC to differentiate it from the shorter . 45 Schofield , as both were used by the army at the same period of time History . The . 45 Colt was a joint development between Colt ' s Patent Firearms Manufacturing Company , of Hartford , Connecticut , and the Union Metallic Cartridge Company of Bridgeport , Conn . Colt began work on the revolver in 1871 , and submitted a sample to the U . S . Army in late 1872 . The revolver was accepted for purchase in 1873 . The cartridge is an inside lubricated type . The rebated heel type bullet design of its predecessor , the . 44 Colt ( . 452 - . 454 " diameter bullet ) , was eliminated , since it was an outside lubricated type , which would pick up dirt and grit during handling . The . 45 Colt replaced the . 50 caliber Model 1871 Remington single shot pistol and the various cap - and - ball revolvers converted to take metallic cartridges in use at the time . While the Colt remained popular , the Smith & Wesson M1875 Army Schofield Revolver was approved as an alternate . The S & W revolver used the . 45 Schofield , a shorter cartridge , which would work in the Colt , so Frankford Arsenal , then almost exclusive supplier of small arms ammunition to the U . S . Army , dropped production of the Colt round . The M1875 round was replaced by the . 38 Long Colt in 1892 . In 1909 , the . 45 M1909 round was issued along with the Colt New Service revolver . This round was never loaded commercially , and is almost identical to the original Colt round , except having a larger diameter rim . The rim is large enough that it cannot be loaded in adjacent chambers in the rod - ejector Colt model . The . 45 Colt remains popular with renewed interest in Cowboy Action Shooting . Additionally , the round has seen resurgence as a cartridge in handgun hunting and Metallic Silhouette Shooting competitions beginning in the 1950s with the introduction of stronger heavier framed handguns . It became the basis for rounds such as the . 454 Casull . Cartridge loads . The . 45 Colt originally was a black - powder cartridge , but modern loadings use smokeless powder . The original black - powder loads called for of black powder behind a lead bullet . These loads developed muzzle velocities of up to . Because of this power and its excellent accuracy , the . 45 Colt was the most - used cartridge at the time of its introduction , succeeding the . 44 WCF ( or the . 44 - 40 Winchester ) . The . 45 Colt never enjoyed the . 44 - 40 ' s advantage of a Winchester rifle chambered for it , allowing use of the same cartridge in both pistol and rifle . The reason was that early . 45 Colt cartridges had a very minimal rim , and would not eject reliably . Currently manufactured brass has a rim of adequate diameter for such uses . Modern Winchesters , Marlins and replicas have remedied this omission almost 100 years after the fact , and the . 45 Colt is now available in modern lever - action rifles . While this has been one of numerous arguments to explain the lack of a rifle chambered in . 45 Colt , in fact , Colt would not authorize the use of their . 45 Colt in other manufacturers ’ arms . It required the expiration of those original patents for the . 45 Colt to become available in a lever action or indeed in any other action rifle . Today ' s standard factory loads develop around of muzzle energy at about , making it roughly equivalent to modern . 45 ACP loads . There are Cowboy Action Shooting loads which develop muzzle velocities of around . Some handloads and factory manufactured cartridges put this round in the same class as the . 44 Magnum . These loads cannot be used in any original Colt Single - Action Army or replica thereof , such as those produced by Uberti , Beretta , the Taurus Gaucho , or the 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 , Redhawk , Ruger Vaquero ( erroneously referred to as the " Old Model " to differentiate it from the " New Model " ) , Thompson Center Contender or any gun firing the . 454 Casull cartridge . Modern rifles with strong actions ( such as the Winchester Model 1894 , Marlin Model 1894 , and new clones of the Winchester Model 1892 ) chambered for the cartridge can safely handle the heavier loadings . Uses . Colt began work on their 1873 Single Action Army Model in 1871 . Sample cartridges submitted for Army tests were made by UMC , using the Benet cup primers ; commercial ammunition used the Berdan - type primer , followed by the more common Boxer priming . Original UMC loads used a powder charge and bullet . This was reduced to of powder , and later , by the Army , to . The . 45 Colt cartridge remains in use years after its introduction . It is used as a hunting load on animals the size of deer and black bear . Heavier handloads will take the same range of big game animals as the . 44 Magnum . Several two - barrel derringer s are sold that are chambered in . 45 Colt , and some of these derringers can chamber a . 410 bore shotgun shell without any modifications being required . Revolvers chambered in . 410 shotgun are usually chambered for the . 45 Colt such as the Taurus Judge and the Smith & Wesson Governor . However , the most popular use for the . 45 Colt today is in Cowboy Action Shooting , where the round is fired from either original or replicas of the 1873 Colt Single - Action Army . Winchester , Marlin , Henry , Chiappa , Rossi , and other manufacturers produce lever - action rifles chambered in . 45 Colt . Colt has resumed production of the Single - Action Army , and many SAA replicas and near - replicas as well as modern - design single - actions by Ruger are chambered for this cartridge . Influence on other cartridges . The . 45 Colt became the basis for the much more powerful . 454 Casull cartridge , with the . 454 Casull having a slightly longer and stronger case . Any . 454 Casull revolver will chamber and fire . 45 Colt , but not the inverse due to the Casull ' s longer case . The . 460 S & W Magnum is a longer version of the . 454 Casull and the . 45 Colt . Likewise , . 460 Magnum revolvers can chamber and fire the two lesser cartridges , but again , not the reverse .