.45 ACP
From The D Archives
The .45 ACP (Automatic Colt Pistol, 11.43 x 23 mm) is a rimless pistol cartridge designed by firearms designer John Browning in 1905, for use in his prototype Colt semi-automatic .45 pistol—a design which evolved into the M1911 pistol adopted by the U.S. Army in 1911.