One of several self-loading (semi-automatic) pistols submitted to the United States Army, intended to supplant the M1892 revolver as the standard-issue sidearm. Chosen on the 29th of March, 1911, the Colt Model of 1911 served as sidearm until early 1985. The .45 caliber ACP cartridge and semi-automatic platform met the demands that the M1892 could not - stopping power, effectiveness in battle conditions, and durability. Even after the adoption of the M9, Marine and other specialized units were outfitted with wartime M1911s. In 2012, the Marines commissioned 12,000 new production pistols based upon the M1911 platform, but with updated mechanisms and finish, now designated the M45.