Browning Machine Gun, Cal. .50, M2, HB
M2HB machine gun
Type	Heavy machine gun
Place of origin	United States
Service history
In service	1921 M2HB from 1933–present
Used by	United States, and several others
Wars	World War II, Korean War, Vietnam War, Cambodian Civil War, Falklands War, Desert Storm, Somali Civil War, Iraqi Freedom, Operation Enduring Freedom, South African Border War
Production history
Designed	1918
Produced	1933–present (M2HB)
Specifications
Mass	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) (887.1 m/s)
Feed system	Belt-fed (M2 or M9 links)

The M2 Machine Gun, or Browning .50 Caliber Machine Gun is a heavy machine gun. It was nicknamed Ma Deuce by US troops or simply called "fifty-cal." due to its caliber.

John Moses Browning (1855–1926) of Ogden, Utah, was the inventor. His military arms were considered to be outstanding. German Field Marshal Hermann Göring said, "If the Luftwaffe (German Air Force) had the Browning .50-caliber, the Battle of Britain would have turned out differently".