7. Barrett M82 The M82, standardized by the US Military as the M107, is a recoil-operated, semi-automatic anti-materiel rifle developed by the American Barrett Firearms Manufacturing company. It is also called the "Light Fifty" for its .50 BMG chambering. The weapon is found in two variants, the original M82A1 (and A3) and the bullpup M82A2. The M82A2 is no longer manufactured, though the XM500 can be seen as its successor.