The Rolls-Royce Experimental Machine Gun was a prototype British

heavy machine gun A heavy machine gun (HMG) is significantly larger than light, medium or general-purpose machine guns. HMGs are typically too heavy to be man-portable (carried by one person) and require mounting onto a weapons platform to be operably stable or ...

, designed by

Rolls-Royce Rolls-Royce (always hyphenated) may refer to: * Rolls-Royce Limited, a British manufacturer of cars and later aero engines, founded in 1906, now defunct Automobiles * Rolls-Royce Motor Cars, the current car manufacturing company incorporated in ...

during

World War II World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...

. Britain wanted to equip aircraft with the Browning M2 .50 caliber machine gun by buying direct from America, but since this was the main heavy caliber machine gun of the

U.S. Army The United States Army (USA) is the primary land service branch of the United States Department of Defense. It is designated as the Army of the United States in the United States Constitution.Article II, section 2, clause 1 of the United Stat ...

and its Air Corps none could be spared for export. Thus Rolls-Royce commenced design of a heavy machine gun in early 1940, intended for use in aircraft. The result was a recoil-operated weapon firing .50 Browning cartridges. This was evaluated in March 1941 and proved prone to stoppages.Hogg 1990, p. 344 A revised gas-operated weapon was designed and built to try to solve these problems. As well as the .50-inch versions, it was planned to modify the gas-operated gun to fire the more powerful .55-inch ammunition used in the

Boys anti-tank rifle The Boys anti-tank rifle (officially Rifle, Anti-Tank, .55in, Boys, and sometimes incorrectly spelled "Boyes") is a British anti-tank rifle used during the Second World War. It was often nicknamed the "elephant gun" by its users due to its siz ...

. All work on the Rolls-Royce machine guns was abandoned in 1942, by which time supply of the M2 Browning from the U.S.A. had started.Birch 2000, p. 94

References

;Notes ;Bibliography *Birch, David. ''Rolls-Royce Armaments''. Derby, UK: Rolls-Royce Heritage Trust. 2000. . *Hogg, Ian V. and Weeks, John S. ''Military Small Arms of the 20th Century''. Iola WI: Krause. 7th Edition, 1990. . .50 BMG machine guns Aircraft guns Trial and research firearms of the United Kingdom Machine guns of the United Kingdom World War II machine guns Rolls-Royce {{machinegun-stub