The 12.7×99mm NATO or .50 BMG (for Browning Machine Gun) is a long range, anti-materiel cartridge. It is based on the .30-06 Springfield, largely upscaled.
The .50 BMG cartridge is also used in long-range target and sniper rifles, as well as other .50 machine guns. The use in single-shot and semi-automatic rifles has resulted in many specialized match-grade rounds not used in .50 machine guns. A McMillan Tac-50 .50 BMG sniper rifle was used by Canadian Corporal Rob Furlong to bring off the then longest-range confirmed sniper kill in history (now 2nd longest-range), when he shot a Taliban combatant at 2,430 meters (2,657 yards) during the 2002 campaign in the Afghanistan War. This record was only recently eclipsed by 2 confirmed kills in November 2009 in Afghanistan against Taliban machine gunners by Craig Harrison, a member of the British Household Cavalry, using an Accuracy International AWM L115A3 long-range rifle chambered for .338 Lapua Magnum 8.59 mm rounds. The shots were measured by GPS at 8,120 ft or 2,706 yards (2,474 m).
The previous record for a confirmed long-distance was set by US Marine sniper Carlos Hathcock in 1967, the distance was 2,286 meters (2,500 yards, 7,500 feet) or 1.42 miles (2.29 km). Hathcock used the .50 BMG in an M2 Browning Machine Gun equipped with a telescopic sight. This weapon was used by other snipers, and eventually purpose-built sniper rifles were developed especially for this round. DARPA (Defense Advanced Research Projects Agency) has developed the EXACTO program, .50 caliber bullets complete with microprocessors and steering vanes that allow the bullet to adjust its trajectory mid-flight to stay on target when the flight path has been altered by uncontrollable variables.
A wide variety of ammunition is available, and the availability of match-grade ammunition has increased the usefulness of .50 caliber rifles by allowing more accurate fire than lower quality rounds.
Developed early in the 1910s, it was introduced into service in 1921 for the M2 Browning Machine Gun. It is still used on vehicles, air, sea, land. Sometimes even deployed on infantry.