When describing small-arms mechanisms, the term automatic refers to a weapon that fires a round, extracts the empty case, ejects the case, compresses a return spring, feeds a round from the magazine, and places it in the chamber ready for firing. The hammer, or firing pin, then strikes the cap of the cartridge and another round is fired.
In a fully automatic weapon, this sequence starts as soon as the trigger is pulled and repeats until the trigger is released. A great number of so-called automatic weapons are, in fact, only semiautomatic, since their trigger mechanisms are so designed that the trigger must be released and pulled again to fire another round. These weapons are better described as self-loading.
Early automatic weapons
The earliest handguns, in use from the early 14th century to the late 19th century, were equipped with matchlock or flintlock firing mechanisms. Once such a gun had been fired, its carrier would be defenseless until the gun had been reloaded.
As early as the 14th century, a number of devices were designed to increase the rate of fire by putting more than one weapon under the control of a single person. These weapons usually took the form of a number of muskets mounted on a frame or on a wagon and so arranged that the application of the sparks from a match or flint to a black powder train set off a number of barrels in quick succession. This type of weapon was known as an organ gun, since the multiple barrels resembled the pipes of a musical organ. Organ guns became more widely used in the 15th century, when a variety of types were produced, some firing in concentration and some producing dispersed fire.
In 1718, a British notary and author, James Puckle, patented a remarkable weapon. Called a Defence, this tripod-mounted weapon had a single 1.2 in. (30 mm) caliber barrel, 32.7 in. (0.83 m) in length, that could be fed with either round or square bullets from a choice of nine chambered cylinders. The cylinder rotated on a ratchet mechanism, positioning the bullets between a flintlock and the barrel. Two interchangeable cylinders increased the rate of fire. The British newspaper The London Journal reported on March 31, 1722, that in a demonstration the weapon managed to fire 63 rounds in 7 minutes, with an impressive average interval of 8.6 seconds between rounds.
In 1861, Richard Gatling, a U.S. dentist and inventor, developed the first truly successful rapid-fire gun. It had six barrels mounted in a frame that rotated around a central axis by a hand-operated crank. Each barrel would fire in turn as the frame rotated; the crank powered the loading, firing, and discharging operations. In some versions, a stacking mechanism con- tinuously fed cartridges to the barrels as they emptied. By 1865, the U.S. Army started to purchase Gatling guns; soon after, every major army followed suit. In a British Army demonstration in 1870, a Gatling gun fired 616 shots in two minutes—more than five rounds per second—although only 369 hit the intended target. The Gatling gun remained in service with the U.S. Army until 1911.
