Automatic Colt Pistol

Automatic Colt Pistol (ACP) denotes various John Moses Browning cartridge designs primarily used in Colt and Fabrique Nationale de Herstal semi-automatic pistols. All of these cartridges are straight-sided and appear similar. The .32 ACP, .38 ACP, and .25 ACP are semi-rimmed and headspace on the rim, while the rimless .45 ACP and .380 ACP headspace on the mouth of the case.