50 cal

50 Caliber Machine Gun, Heavy barrel is an automatic, recoil-operated, air-cooled machine gun with adjustable headspace and is crew transportable The .50 Browning Machine Gun (.50 BMG) or 12.7×99mm NATO is a cartridge developed for the Browning .50 caliber machine gun in the late 1910s. The cartridge itself has been made in many variants: multiple generations of regular ball, tracer, armor piercing, incendiary, and saboted sub-caliber rounds.