His theories are now axioms, as the MAC has become almost notoriously known as the most reliable sub-machine gun ever built. He also believed in the philosophy that the fewer the working parts, the less that things can break. His M10, in the early 1970s, embodied the spirit of making things smaller, more compact, and less expensive. 45ACP at his Powder Springs Georgia plant, little did he know that this design would be one that would captivate a number of different types of machine gun enthusiasts. Ingram first designed his M10 in 9mm and. A Comparison Of The Military Armament Corporation Model 10/9mm (MAC-10/9) And The Sylvia And Wayne Daniels M11 (SWD M11/9) and other MAC-type weapons.