The .45 ACP (Automatic Colt Pistol, 11.43 x 23 mm ) pistol cartridge was designed by firearms designer John Browning. Its manufacture and use was facilitated by the fact that it is essentially a cut-off version of the .30-06 Springfield rifle cartridge, which was formally introduced in 1906 and went on to become the standard U.S. military rifle cartridge from that time for more than 50 years. The .45 ACP was developed in 1905 for a prototype Colt pistol, which evolved into the M1911 pistol adopted by the U.S. Army in 1911. The round would become one of the most successful cartridges of all time, among both military and civilian users. It has been used in innumerable handguns and submachine guns (including most famously the Thompson submachine gun) since its introduction.