The Browning M2, known by its nickname "Ma-Deuce" or commonly known as the Browning .50 Cal. is an air-cooled, recoil-operated, heavy machine gun that was used by the United States during World War II.
With a weight of 38 kg and a length of 165.6 cm, the M2 fired the .50 BMG (12.7x99) Cartridge, and had a cyclic rate of fire of 550 rounds per minute. It was fed by 110 round ammo belts that are usually kept in ammo boxes. The M2 also had a crew that could vary between two men to four men. The M2 had leaf-type iron sights and was made to have several accessories including a tripod, the ability to switch barrels, and a flash suppressor.
As an anti-aircraft weapon, the 12.7 mm round was generally quite reliable, especially when used in the numbers mounted on most American aircraft. It's high velocity and powerful round were also well capable of penetrating armor, meaning that Browning M2s mounted on American light vehicles were effective against their contemporaries which sometimes carried a far heavier armament.
As an infantry weapon, the M2 was limited in its use considering how bulky it is to be transported by men across a battlefield. Among the various mountings that the M2 could be placed on was the M45 Quadmount, where four M2HBs were placed in an anti-aircraft turret.
- AN/M2 Browning: A modified version adopted as the standard weapon for American aircraft, which boasted an increased rate of fire. Fighters mounted them on fixed installations in the wings and fuselage, while bombers used it in both turret and free swinging mounts. [N 1]
- M2HB "Heavy Barrel": Featured a heavier grade barrel so that the weapon was air-cooled, essentially the standard M2
- M3 Browning: While a post-war derivative, the M3 Browning was an air-cooled variant that boasted an even faster fire rate (~1000 RPM). This variant was fitted to post-war American fighter aircraft (like the F-80 Shooting Start & F-82 Twin Mustang) but was phased out in the 1960s in favour of cannon armament, in particular rotary cannon-type armament like the M61 Vulcan.
The M2 began its development towards the end of World War I following a request for a large caliber machine gun capable of operating in the anti-aircraft role. Taking on the task was John Browning and Fred Moore who adapted the existing Browning M1919 machine gun into the M1921 Heavy Machine Gun, completing their work in 1921. The M1921 was water-cooled and was produced by Colt through the 1930s, eventually leading up to the M1921A1, and subsequently the M2HB, which finally fixed the fracturing issues in the barrel and allowed the weapon to keep up a reliable rate of fire. From then on, the M2 became one of the most famous weapons used by the United States during World War II. It was used in everything from aircraft to tanks to jeeps. Ever since its creation the "fifty cal" was used wherever the United States Army or its allies fought, and so far all attempts to replace it have failed.
- In the latter form, the twin spade grip handles and thumb operated trigger were retained.
- Williams, Anthony G. Rapid Fire - The Development of Automatic Cannon, Heavy Machine Guns and their Ammunition for Armies, Navies and Air Forces. Airlife Publishing. 2000. ISBN 1-84037-122-6 Page 153.