The M82 is a short-recoil semi-automatic firearm. When the gun is fired, the barrel initially recoils for a short distance (about 1 in (25 mm)), while being securely locked by the rotating bolt. After the short travel, a post on the bolt engaged in the curved cam track in the receiver turns the bolt to unlock it from the barrel. As soon as the bolt unlocks, the accelerator arm strikes it back, transferring part of the recoil energy of the barrel to the bolt to achieve reliable cycling. Then, the barrel is stopped and the bolt continues back, to extract and eject a spent case. On its return stroke, the bolt strips the fresh cartridge from the box magazine and feeds it into the chamber and finally locks itself to the barrel. The striker is also cocked on the return stroke of the bolt. The gun is fed from a large, detachable box magazine holding up to 10 rounds, although a rare 12-round magazine was developed for use during Operation Desert Storm in 1991.
The M82A2 differed from M82A1 mostly in its configuration; the pistol grip along with trigger was placed ahead of the magazine, and the buttpad placed below the receiver, just after the magazine. An additional forward grip was added below the receiver, and the scope mount was moved forward.
The maximum effective range of the M107 is 1,830 metres (2,000 yd). The maximum range of this weapon (specifically the M107 variant) is 4,000 metres (4,400 yd), as quoted in the owner's manual. Fifty caliber (and larger) rounds have the potential to travel great distances if fired in an artillery-like fashion, necessitating the observance of large safety margins when firing on a range.