The XM-50 HMG is an air-cooled, belt-fed machine gun. The XM-50 fires from a closed bolt, operated on the short recoil principle. It fires the .50 BMG cartridge, which offers longer range, greater accuracy, and immense stopping power. The closed bolt firing cycle made the XM-50 usable as a synchronized machine gun on aircraft before and during World War II, as on the early versions of the Allied aircraft.