Machine gun

[1] Nowadays, the term is restricted to relatively heavy crew-served weapons, able to provide continuous or frequent bursts of automatic fire for as long as ammunition feeding is replete.

They are commonly mounted on fast attack vehicles such as technicals to provide heavy mobile firepower, armored vehicles such as tanks for engaging targets too small to justify the use of the primary weaponry or too fast to effectively engage with it, and on aircraft as defensive armament or for strafing ground targets, though on fighter aircraft true machine guns have mostly been supplanted by large-caliber rotary guns.

Although subdivided into "light", "medium", "heavy" or "general-purpose", even the lightest machine guns tend to be substantially larger and heavier than standard infantry arms.

During the Vietnam War, Carlos Hathcock set the record for a long-distance shot at 7,382 ft (2,250 m) with a .50 caliber heavy machine gun he had equipped with a telescopic sight.

Most modern machine guns are of the locking type, and of these, most utilize the principle of gas-operated reloading, which taps off some of the propellant gas from the fired cartridge, using its mechanical pressure to unlock the bolt and cycle the action.

The continuous nature of the rotary action and its relative immunity to overheating allow for a very high cyclic rate of fire, often several thousand rounds per minute.

Whereas such weapons are highly reliable and formidably effective, one drawback is that the weight and size of the power source and driving mechanism makes them usually impractical for use outside of a vehicle or aircraft mount.

It was also claimed that the gun could be reloaded 'as often as you like' and fired no matter the weather though the English government never adopted the weapon despite testing being carried out at the Tower of London.

[14][15] In 1711, a French lawyer called Barbuot presented to the parliament of Dijon a crank-operated 'war machine' made up of 10 carbine barrels and loaded via a 'drum' capable of firing in vollies.

[21] In 1737, it was mentioned that Jacob de Weinholtz, a Dane who was serving in the Portuguese army, had invented a cannon capable of firing 20 to 30 shots a minute though requiring 15 people to work it.

[27][28] In 1764, Frenchman Ange Goudar wrote in his work The Chinese Spy that he had assisted in Paris in the proofing of a 'great gun' capable of firing 60 times in a minute.

[30][31] In 1775, it was mentioned that in England two large cannons invented by an unidentified matross at Woolwich had achieved a rate of fire of 59 shots in 59 and a half seconds.

[50][51][52] In 1825 an Italian book attempting to catalogue all topographic features of all known countries on Earth mentioned that in France there were 'mechanical rifles' used to defend warehouses that were capable of firing 120 shots without reloading.

[53] In 1828, a swivel gun that did not need cleaning or muzzle-loading and was capable of being made to any dimensions and used as an ordinary cannon at a moment's notice and firing 40 shots a minute was invented by a native of Ireland.

The French government showed interest at first and while it noted that mechanically there was nothing wrong with Steuble's invention it turned him down, stating that the machine both lacked novelty and could not be usefully employed by the army.

The gun was reportedly breech-loading, fed by cartridges from some kind of hopper and could fire 34 barrels of one-inch calibre 4 or 6 times for a total of 136 or 204 shots a minute.

The model described is small in scale and works by rotating a series of barrels vertically so that it is feeding at the top from a "tube" or hopper and could be discharged immediately at any elevation after having received a charge, according to the author.

[72] In 1848, the Italian Cesare Rosaglio announced his invention of a machine gun capable of being operated by a single man and firing 300 rifle shots a minute or 12,000 in an hour after taking into account the time needed to reload the "tanks" of ammunition.

[73] In June 1851, a model of a 'war engine' allegedly capable of firing 10,000 ball cartridges in 10 minutes was demonstrated by a British inventor called Francis McGetrick.

[76] A model of this weapon, said to be capable of firing 1800 shots in a minute with great precision at 2000 yards and drawn by two horses, was constructed and tested though apparently not adopted for the military.

The weapon featured a single barrel and fired through the turning of the same crank; it operated using paper cartridges fitted with percussion caps and inserted into metal tubes that acted as chambers; it was therefore functionally similar to a revolver.

Early multi-barrel guns were approximately the size and weight of contemporary artillery pieces, and were often perceived as a replacement for cannon firing grapeshot or canister shot.

[85] Sustained firing of gunpowder cartridges generated a cloud of smoke, making concealment impossible until smokeless powder became available in the late 19th century.

[85] The Gatling gun was used most successfully to expand European colonial empires, since against poorly equipped indigenous armies it did not face such threats.

[85] In 1864, in the aftermath of the Second Schleswig War, Denmark started a program intended to develop a gun that used the recoil of a fired shot to reload the firearm though a working model would not be produced until 1888.

The biggest single cause of casualties in World War I was actually artillery, but combined with wire entanglements, machine guns earned a fearsome reputation.

The most effective position for guns in a single-seater fighter was clearly, for the purpose of aiming, directly in front of the pilot; but this placement would obviously result in bullets striking the moving propeller.

New designs largely abandoned water jacket cooling systems as both undesirable, due to a greater emphasis on mobile tactics; and unnecessary, thanks to the alternative and superior technique of preventing overheating by swapping barrels.

While this machine gun was equally able in the light and medium roles, it proved difficult to manufacture in quantity, and experts on industrial metalworking were called in to redesign the weapon for modern tooling, creating the MG 42.

As it became clear that a high-volume-of-fire weapon would be needed for fast-moving jet aircraft to reliably hit their opponents, Gatling's work with electrically powered weapons was recalled and the 20 mm M61 Vulcan was designed; as well as a miniaturized 7.62 mm version initially known as the "mini-Vulcan" and quickly shortened to "minigun" soon in production for use on helicopters, where the volume of fire could compensate for the instability of the helicopter as a firing platform.