U.S. Marines firing the M2 .50 Caliber machine gun. The M2 Machine Gun, Browning .50 Caliber Machine Gun, is a heavy machine gun designed during WWI by John Browning. The M2 uses the larger and more powerful .50 BMG cartridge, which was named for the gun itself (BMG standing for Browning Machine Gun). The M2 has been referred to as "Ma Deuce" or "the fifty" in reference to the 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. Courtesy DVIDS, Third Army/U.S. Army Central (ARCENT), Department of the Army. DVIDS metadata: "B-Roll of Marines firing the M2 .50 Caliber Machine Gun as well as taking a class on the M240 Machine Gun during Javelin Thrust 2011. Also available in high definition. Video by Lance Cpl. Nicholas Neighbors. Javelin Thrust. Date: 07.23.2011.