The M60D machine gun is a 7.62mm calibre automatic, gas-operated machine gun that is mounted on the Chinook helicopter and can be fired from either side of the cabin, or from the aircraft’s rear ramp. The gun is attached to a mount fixed to the aircraft that permits it to swivel freely between mechanical stops, which prevent damage to the aircraft during firing. An ammunition-can assembly, and an ejection-control bag to collect spent cartridge cases, are supplied to each mount and are fitted directly to the gun. The gun is fired manually at up to 550 rounds per minute.