M61 20 mm fighter plane cannon

The M61 Vulcan is a 20 mm hydraulically or pneumatically driven, six-barreled, air-cooled, electrically fired Gatling-style cannon with an extremely high rate of fire. It has been the principal cannon armament of United States military aircraft for five decades. The M61 was originally produced by General Electric, and after several mergers and acquisitions is currently produced by General Dynamics