380 ACP version was introduced later in the same year. 45 ACP versions were introduced simultaneously. In 1970, the company Ingram worked for, Sionics Inc, was merged into the larger Military Armament Corporation, and there MAC-10 was put into production. The Ingram Model 10, better known as the MAC-10, named after its producer Military Armament Corporation, is an American open bolt submachine gun designed by Gordon Ingram in 1965.
