ACP – Automatic Colt Pistol
Automatic Colt Pistol is usually used in correlation to the caliber.
It denotes various John Browning cartridge designs. These designs primarily used in Colt and Fabrique Nationale de Herstal pistols. All of these cartridges are straight-sided and appear similar.
🔸️ The .25 ACP, .32 ACP, and .38 ACP are semi-rimmed and headspace on the rim
🔸️ The .380 ACP and .45 ACP are rimless and headspace on the mouth of the case.