45 ACP (Automatic Colt Pistol) cartridge ... according to Garry James of Guns & Ammo Handguns magazine. Indeed, during the revolver’s first “blooding” during the Spanish-American War ...
COLT M1911 is a single-action, semi-automatic, magazine-fed, recoil-operated pistol chambered for the .45 ACP cartridge. It served as the standard-issue sidearm for the United States Armed Forces ...