The XM301 Cannon is an externally-powered, three-barrel 20 mm Gatling gun made by General Dynamics for the U.S. Army. Developed for use with the RAH-66 Comanche stealth helicopter, it is the world's lightest 20 mm Gatling cannon. The XM301 was designed to be a versatile and accurate lightweight cannon that could serve both an air-to-air and air-to-ground role. Development and manufacture of the XM301 was cancelled in 2004 along with its parent RAH-66 program.