The Browning M2 (commonly called "Ma Deuce") was designed at the end of World War I by John Browning, responding to the Army Ordnance Department's request for a heavy machine gun capable of being used in anti-aircraft and anti-infantry rounds. Initial design work was completed in 1918, creating a scaled-up M1917 .30 machine gun built around a purpose-built .50 round. The first working units were produced in 1921, using water-cooled barrels, with subsequent development leading to the creation of the M2 in 1932, which would remain in service for decades.
The resulting .50 caliber machine gun combines the rugged design of its ancestor with the extremely powerful .50 round, highly effective against infantry and other soft targets, materiel, lightly armored vehicles, boats, fortifications, and aircraft. Though heavy and cumbersome when used away from a mount, the advent of power armor and the creation of minigun frames for personnel use allowed this venerable weapon to be used by soldiers on foot.