M107, 0.50 caliber BMG,Barrett

The M82 (also more recently known as the M107) is a heavy SASR (Special Application Scoped Rifle) developed by the American Barrett Firearms Company. It is used by many units and armies around the world, including the American Special Forces. It is also called the "Light Fifty" for its .50 caliber BMG (12.7 mm) chambering. The weapon is found in two variants — the original M82A1 (and A3) and the bullpup M82A2. The M82A2 is no longer manufactured, though XM500 can be seen as its successor, in that it also employs a bullpup configuration.

Firearms Company was founded by Ronnie Barrett for the single purpose of building semi-automatic rifles chambered for the powerful 12.7x99mm NATO (.50 BMG) ammunition, originally developed for and used in M2 Browning machine guns. Barrett began his work in the early 1980s and the first working rifles were available in 1982, hence the designation M82. Barrett continued to develop his rifle through the 1980s, and developed the improved M82A1 rifle by 1986.

The first conventional military success was the sale of about 100 M82A1 rifles to the Swedish Army in 1989. Major success followed in 1990, when the US Military purchased significant numbers of the M82A1 during operations Desert Shield and Desert Storm in Kuwait and Iraq. About 125 rifles were initially bought by the US Marine Corps, and orders from US Army and Air Force soon followed. The M82A1 is known by the US Military as the SASR — "Special Applications Scoped Rifle", and it was and still is used as an anti-matériel weapon and EOD (explosive ordnance disposal) tool. The long effective range, over 1500 m with a record shot of 2500 m[citation needed], along with high energy and availability of highly effective ammunition such as API and Raufoss Mk 211, allows for effective operations against targets like radar cabins, trucks, parked aircraft and so on. The M82 can also be used to defeat human targets from standoff range or when targets are behind cover. However anti-personnel work is not a major application for the M82 (or any other .50 BMG rifle, for that matter). There is a widespread misconception that a number of treaties have banned use of the .50 BMG against human targets, and recruits have been advised by generations of drill instructors to only aim a .50 BMG at an enemy soldier's web gear or other equipment worn on his body. However, the U.S. Army Judge Advocate General's office has issued a legal opinion that the .50 BMG and even the Raufoss Mk 211 round are legal for use against enemy personnel.

Further development led to the M82A2 bullpup rifle in 1987, which was a reduced-recoil design to be fired from the shoulder. It failed to make an impression on the world firearms market, and was soon dropped from production. However, in 2006, Barrett had developed the XM500, with a bullpup configuration similar to the M82A2.

M107, almost identical to the M82A1M/A3.
The latest derivative of the M82 family is the M82A1M rifle, adopted by USMC as the M82A3 SASR and bought in large numbers. This rifle differs from M82A1 in that it has a full length Picatinny rail that allows a wide variety of scopes and sighting devices to be mounted on the rifle. Other changes are the addition of a rear monopod, slightly lightened mechanism and detachable bipod and muzzle brake.