The .45 Colt (11.43×33mmR), is a rimmed, straight-walled, handgun cartridge dating to 1872. It was originally a black-powder revolver round developed for the Colt Single Action Army revolver. This cartridge was adopted by the U.S. Army in 1873 and served as an official US military handgun cartridge for 14 years. 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, which created a logistical problem for the Army. The S&W revolver used the .45 S&W Schofield, a shorter cartridge, which would also work in the Colt, however the Army's S&W Schofield revolvers could not chamber the longer .45 Colt, so in 1874 Frankford Arsenal, then almost exclusive supplier of small arms ammunition to the U.S. Army, dropped production of the .45 Colt cartridge in favor of the .45 S&W round. This resolved the Army's ammunition logistics problems, but there were still plenty of the longer Colt-length cartridges in circulation once production ceased. The Benet primed .45 Revolver cartridges were subsequently replaced by the 'Model of 1882 Ball Cartridge for Cal. .45 Revolver' which used an external Boxer primer and could be reloaded at the unit level. The .45 caliber M1882 cartridge would be officially replaced by the .38 Long Colt in 1892 but would remain in production until 1896. In 1901-1902 it would once again be loaded by Frankford Arsenal for use in the Philippines. In 1909, the .45 M1909 round was issued along with the .45 Colt New Service revolver. This round was never loaded commercially, and is almost identical to the original .45 Colt round, except having a larger diameter rim (.540 in (13.7mm)). The rim is large enough