First of all, let us explain, this is not a machine gun, this here folks is the 25mm (0.98 inch caliber) autocannon, and it has been in service since 1972 with explosive results, um literally.

It is used by a few ground vehicles like the very famous Bradley Fighting Vehicle (both M2 and M3 versions) and the Marine Corp’s LAV-25, the eight-wheeled light armored amphibious reconnaissance vehicle.