The M3R Aircraft Machine Gun is a recoil operated, air cooled, belt-fed machine gun. This gun is designed for all .50 cal. aircraft machine gun installations. By properly repositioning a portion of the parts, the gun may be fed from either the right or the left hand side. The weapon is furnished as a basic gun to which various accessories may be added. Direct or remote charging devices, rear or side plate firing solenoids, and various backplate configurations enable the weapon to be configured to satisfy customer requirements.