M-60D Medium Machine Gun

M-60D Medium Machine Gun is machine gun.The venerable M-60 soldiers on, its original German feed mechanism (lifted from the MG-42) still intact. It is the standard medium machinegun of the U.S. military, and is virtually identical to Germany's new medium MG; certain internal parts of both guns are interchangeable. The M-600 uses 100-round belts of plastic-cased 7.62mm ammunition. This has only two-thirds the cost of metal-cased ammo. The plastic casings are made of a heat-absorbing and -resistant material which acts as a thermal sink, keeping the air-cooled machinegun from overheating. Uses cased ammo.

Source

 * Home of the Brave, pg.83
 * Blackhand's Street Weapons, pg.33