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 o ...

, 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 ...

during

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the World War II by country, vast majority of the world's countries—including all of the great power ...

. 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 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 The .50 Browning Machine Gun (.50 BMG, 12.7×99mm NATO and designated as the 50 Browning by the C.I.P.) is a caliber cartridge developed for the M2 Browning heavy machine gun in the late 1910s, entering official service in 1921. Under STANA ...

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 s ...

. 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