Barrett M82 / M107

The Barrett M82 was developed by Barrett Firearms Manufacturing, a company founded by Ronnie Barrett in the United States for the specific purpose of building a semi-automatic rifle chambered for the .50 BMG cartridge, a round originally developed for the M2 Browning machine gun. The first sale was to the Swedish Army in 1989. In 1990, during Operations Desert Shield and Desert Storm, the United States Marine Corps purchased an initial batch of the rifles, with Army and Air Force orders following. The U.S. military initially designated the weapon the SASR, or "Special Applications Scoped Rifle." The designation XM107 was first applied to the bolt-action Barrett M95, selected by the U.S. Army in a competition that concluded the service did not require such a weapon; in summer 2002 the M82 emerged from Army trials and was adopted as the Long Range Sniper Rifle, Caliber .50, M107.

The M82 operates on the short-recoil principle. On firing, the barrel recoils a short distance while locked by a rotating bolt. An accelerator arm hinged in the bolt carrier transfers part of the barrel's recoil energy to the bolt, which unlocks by turning in a curved cam track in the carrier. The barrel is arrested by the combined action of the accelerator, buffer spring, and muzzle brake, while the bolt continues rearward to extract and eject the case, cocking the striker on its return stroke before stripping a fresh round from the detachable box magazine. The receiver consists of upper and lower halves stamped from sheet steel and joined by cross-pins. The heavy barrel is fluted for heat dissipation and weight reduction and carries a reactive muzzle brake, round in cross-section on early production and of two-chamber rectangular form on later rifles. Rifles are fitted with a scope mount, folding backup iron sights, a folding carrying handle, and a folding bipod; a rear monopod socket and soft recoil pad are present on later models. The M82A1 and M82A3 can be mounted on M3 or M122 infantry tripods or on a Barrett soft-mount for vehicle use. The M82A2 relocated the pistol grip and trigger ahead of the magazine with the buttpad below the receiver, adding a forward grip. The M107A1 uses aluminium and titanium components and a QDL muzzle brake designed to accept a suppressor.

Variants include the M82A1 with redesigned muzzle brake, the M82A1A optimised for the Raufoss Mk 211 round, the M82A1M with lengthened accessory rail, rear grip, and monopod socket, the M82A3 built to M82A1M specification but without rear grip or monopod socket, and the M107. The bullpup M82A2 is out of production; the XM500, completed in 2006, uses a similar configuration. In 2002 an M82A1 served as the platform for the Objective Sniper Weapon prototype firing 25 mm high-explosive shells, later designated XM109. The rifle has been purchased by military and police forces in at least thirty countries. Non-state users have included the Provisional IRA, which smuggled rifles into Ireland during the 1980s and whose snipers killed five soldiers and a constable between 1992 and 1997. Tennessee named the M82 its official state rifle on 26 February 2016. The U.S. Army and Marine Corps began fielding the Mk22 MRAD in 2021 as a replacement.