M2 Browning machine gun Country United States Type Heavy machine gun Manufacturer Browning Introduction 1918 Specifications Weight 38 kg (84 lb), 58 kg (128 lb) with tripod and T&E Length 1650 mm (65 in) Barrel length 1143 mm (45 in) Cartridge .50 BMG Action Short recoil-operated Rate of fire 450–600 rounds/min (M2HB) 750-850 rounds/min (M2 aircraft gun) Muzzle velocity 2,910 feet per second (M33 Ball) Feed system Belt-fed (M2 or M9 links)

The M2 Machine Gun, or Browning .50 Caliber Machine Gun is a heavy machine gun designed towards the end of World War I by John Browning. It was nicknamed Ma Deuce by US troops or simply called fifty-cal. in reference to its caliber. The design has had many specific designations; the official designation for the current infantry type is Browning Machine Gun, Cal. .50, M2, HB, Flexible. It is effective against infantry, unarmored or lightly-armored vehicles and boats, light fortifications, and low-flying aircraft.

The Browning .50 machine gun has been used extensively as a vehicle weapon and for aircraft armament by the United States from the 1920s to the present day. It was heavily used during World War II, the Korean War, the Vietnam War, as well as during operations in Iraq in the 1990s and 2000s. It is the primary heavy machine gun of NATO countries, and has been used by many other countries. It is still in use today, with only a few modern improvements. The M2 has been in use longer than any other small arm in U.S. inventory. It was very similar in design to the smaller Browning Model 1919 machine gun.