The .380 ACP (Automatic Colt Pistol) (also referred to as the "9mm Short", "9mm Browning", "9 mm Kurz", "9mm Corto", "9x17mm") pistol cartridge is a rimless, straight-walled pistol cartridge developed by firearms designer John Browning. It was introduced in 1908 by Colt, and has been a popular self-defense cartridge ever since.