Machine Gun

(redirected from Auto Sear)
Also found in: Dictionary, Thesaurus.

small arms

small arms, firearms designed primarily to be carried and fired by one person and, generally, held in the hands, as distinguished from heavy arms, or artillery.

Early Small Arms

The first small arms came into general use at the end of the 14th cent. Initially they were nothing more than a small cannon held in the hands, fired by placing a lighted match at the touchhole; later a stock was added. The matchlock, the first real handgun, was fired by pulling a trigger that moved a lighted match to the touchhole; it was superseded by the wheel lock, which was fired by a spark-producing mechanism that ignited the gunpowder. By the end of the 16th cent. the wheel lock had been replaced by the flintlock, in which flint striking against steel produced a spark to fire the powder. Early matchlocks, wheel locks, and flintlocks bore many different names; common types included the musket, harquebus, and pistol. The musket was a heavy military firearm designed to be fired from the shoulder; the harquebus, an earlier and heavier weapon, was fired from a support. The pistol, in contrast, was designed to be held and fired with one hand.

Evolution of the Rifle

The rifle, invented in the 15th cent., is a firearm with a grooved, or rifled, bore that imparts a spinning motion to the bullet, giving it greater accuracy. (The principle of rifling the inner surface of the barrel is applied also to artillery.) Rifles first came into widespread practical use in the E United States. Because of its slow rate of fire and its manufacturing cost, the rifle remained relatively unused as a military weapon in Europe. Until the middle of the 19th cent. the musket was the standard small arm.

In the early 19th cent. firearms were revolutionized by the invention of the percussion-cap method of igniting gunpowder. The percussion cap was a small metal capsule, filled with fulminate of mercury, that exploded when struck and fired the gun instantly; it soon replaced the flintlock. Another important advance was the development of gas-expanding bullets, such as the minié and Burton bullets, in the 1840s. In 1855 the United States adopted a new form of firearm called the rifled musket—a gun that looked like a musket, used the minié bullet, had a rifled barrel, was muzzle-loaded, and was fired by percussion caps. It was used by both sides in the U.S. Civil War. Thereafter all small arms became rifled with the exception of the shotgun, a smoothbore firearm designed for short-range firing of either a single slug or a number of small shot. Shotguns are either double-barreled or single-barreled and can be single-shot or repeaters; they are used mainly for hunting.

Breechloaders and Revolvers

Although gunsmiths had experimented with breech-loading cannon and small arms almost since the invention of firearms, it was not until c.1870 that practical breech-loading firearms came into general use. By the 1880s magazine loading, smokeless powder, and the bolt action had also been developed in Europe and the United States and were in general use in military small arms.

Although the earliest examples of the revolver date from the second half of the 16th cent., and a usable multifiring weapon of the pistol type, called the “pepperbox,” appeared in the first quarter of the 19th cent., it was not until Samuel Colt patented his revolving pistol that the revolver won a place as one of the world's standard small arms. Colt's weapon was a pistol with a revolving cylinder, capable of firing several shots without reloading. The revolver and the magazine-loading rifle were the standard small arms throughout the world in the last part of the 19th cent. until the invention of automatic firearms shortly before 1900.

Automatic Weapons

Automatic small arms were developed almost exclusively by inventors of American birth. A forerunner of the modern machine gun was built by R. J. Gatling during the Civil War. Later types of machine guns, which fired rifle bullets with great rapidity and whose firing mechanism worked by either the power of the gun's recoil or the force of the expanding gases, were developed by Hiram Maxim, B. Hotchkiss, I. N. Lewis, and J. M. Browning. Machine guns were used with terrible effectiveness in many colonial wars, especially by the British, Germans, and Americans, yet their effect on massed infantry still came as a horrible surprise to Europeans in the first year of World War I.

In the years just before and after World War I a host of new automatic small arms were developed. The automatic pistol to some extent replaced the revolver as the standard military sidearm; the revolver, however, remained the weapon of most police forces in the United States even though it has less fire power and carries less ammunition than the automatic pistol—mainly because, unlike the automatic, it did not jam. The submachine gun, a light, portable automatic weapon fired either from the hip or the shoulder, was sometimes employed by the Germans and Italians during World War I. In the United States, J. T. Thompson, in cooperation with J. N. Blish, perfected (1920) one of the first notable submachine guns. The Thompson submachine gun (nicknamed “tommygun” after its inventor) fires .45-caliber cartridges at a rate of 450 to 600 rounds per minute. It was used extensively in World War II as were more recently developed submachine guns such as the British Sten gun and the American weapon known as the M-3 or “grease gun” (because of its resemblance to the air-pressure devices used in automobile lubrication).

Just before World War I the automatic rifle, sometimes known as the light machine gun or machine rifle, was developed; part rifle, part machine gun, it is mounted on a bipod, has a shoulder stock, and is magazine-fed. Outstanding types of this weapon are the British Bren gun and the American Browning Automatic Rifle (BAR). During World War II the bolt-action rifle was supplanted by the semiautomatic Garand rifle—a clip-fed, gas-operated shoulder weapon weighing just over 9 lb (4.1 kg) and firing .30-caliber ammunition. It was the standard service rifle of the U.S. Army and Marine Corps during World War II and the Korean conflict.

After World War II, the United States and the Soviet Union adapted automatic rifles to the use of reduced-power bullets. The American M-16 rifle, which is widely used, can be fired accurately up to 500 yd (457 m) when hand-held and up to 800 yd (732 m) when mounted. The Soviet AK-47 Kalashnikov automatic rifle and the Israeli Uzi submachine gun are particularly effective and famous weapons.

Bibliography

See W. Y. Carman, A History of Firearms from Earliest Times to 1914 (1955); A. J. Cormack, Small Arms in Profile (1972); E. C. Ezell, Small Arms of the World (11th ed. 1977); J. Ellis, The Social History of the Machine Gun (1973).

The Columbia Electronic Encyclopedia™ Copyright © 2022, Columbia University Press. Licensed from Columbia University Press. All rights reserved.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Machine Gun

 

an automatic firearm, designed to hit ground, air, and naval targets with bullets.

Machine guns have been adopted by motorized rifle (infantry or motorized infantry), antiaircraft machine gun, and other subunits, as well as tanks and other combat vehicles and airplanes, including helicopters. Depending on design and combat designation, machine guns are classified as light, heavy, and general-purpose. Those used to fire at aerial targets are called antiaircraft machine guns, and the machine guns with which airplanes and helicopters are armed are called aircraft machine guns. There are several variations, such as wing-mounted, synchronized, and turret machine guns. Machine guns mounted on tanks are called tank machine guns. They may be coaxial, antiaircraft, bow, or turret-mounted. Machine guns are divided into main-caliber guns (6.5–8.0 mm) and large-caliber guns (12.7–15 mm).

In most machine guns, automatic action is provided by the energy of escaping powder gases, although some use the energy of the recoil of the barrel. The basic parts and mechanisms of a machine gun usually include the barrel, receiver, breechblock, trigger mechanism, return spring (mechanism), sight, and magazine (ammunition tray). Light and general-purpose machine guns also have stocks, usually with a handle, and a bipod. Heavy and large-caliber guns also have stands. Ammunition is fed to the gun from a belt or magazine. Fire is usually waged by long bursts; fire from light machine guns may be by short bursts and, from some machine guns, by single shots. The performance characteristics of machine guns are given in Table 1.

The first machine gun was invented by H. S. Maxim, in 1883, and machine guns were first used in the Anglo-Boer War of 1899–1902. Improved by Russian gunsmiths, the Maxim machine gun was adopted by the Russian Army and used in the Russo-Japanese War of 1904–05. In the early 20th century the infantry of several armies adopted light machine guns, including the Danish model of Madsen in 1902 and the French machine gun of Chauchat in 1907, in addition to heavy machine guns. Light machine guns were also first used in the Russo-Japanese War; at the time they were called rifle-machine guns. During World War I heavy and light machine guns were used extensively in all armies.

Table 1. Performance characteristics of machine guns
Name and year of adoptionWeight (kg1Sighting range(m)Bullet weight(g)Muzzle velocity (m/sec)Rate of fire(rounds/min)Capacity of magazine or belt
1General-purpose machine guns: bipod/with a mount box-type magazine 2 Capacity of magazine/capacity of belt 3 Capacity of drum-type magazine/capacity of box-type magazine
General-purpose      
Kalashnikov 7.62 mm (Soviet) .............9/16.71,5009.6825650250/1002
M-60 7.62 mm (1956, American) ......10.4/19.41,1009.3840600250
L7A1 7.62 mm (1961, British) .........10.2/28.41,8009.3843750100
Light      
Degtiarev 7.62 mm (Soviet) .............10.41,5009.684060047
Kalashnikov 7.62 mm (Soviet) .............5.61,0007.974560075/403
M 1919 7.62 mm Browning (1943, American) ......16.251,8309.85853150250
Heavy      
SG-437.62mm (Soviet) ............40.42,0009.6865700250
MK-1 Vickers 7.69 mm (1919, British) .........40.82,80011.3750250250
Large-caliber      
DShK12.7mm (Soviet) ............1573,5005285060050
KPVT 14.5 mm Tank (Soviet) ............52.52,0006494560050
M2HB12.7mm (1937, American) ......581,83046.2895600110

The heavy machine gun was operated by a squad, or crew, of six to eight soldiers. For movement it was broken down into several parts and carried by three or four soldiers. During the war, tanks and airplanes were armed with machine guns. The German Army adopted the 1918-model large-caliber (13.35 mm) machine gun. After the war, large-caliber machine guns were adopted in other armies, including the 8-mm Hotchkiss in the French Army, the 12.7-mm Vickers in the British Army, and the 12.7-mm Browning in the US Army. Large-scale adoption of machine guns led to changes in tactics and in troop organization. Many armies formed machine gun squads within platoons, machine gun platoons within rifle companies, and machine gun companies within battalions.

The Soviet Army adopted the V. A. Degtiarev light machine gun (called the DP) and the large-caliber machine gun of Degtiarev and G. S. Shpagin (called the DShK). In World War II all warring armies had sophisticated machine guns. The Soviet Army used a modernized version of the DP, which was called the DPM, and adopted the 1943 heavy machine gun designed by P. M. Goriunov, called the SG-43. The mount for the machine gun was developed by Degtiarev and permitted fire against both ground and aerial targets. After the war, the Soviet armed forces adopted the 1946 company machine gun (a variation of the light machine gun) designed by Degtiarev, the Degtiarev light machine gun, and the Kalashnikov light machine gun.

In the armed forces of most countries, light and heavy machine guns have been replaced by general-purpose machine guns, which are a lighter variation of the heavy machine gun. General-purpose machine guns provide greater maneuverability on the field of battle and may be used in both the hand-held (with a bipod) and mounted (on a tripod) variations. Mounted machine guns may have light (about 10–15 kg) or stable mounts.

G. M. SHINKAREV

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.

machine gun

[mə′shēn ‚gən]
(ordnance)
A weapon that automatically fires small-arms ammunition, caliber .60 or 15.24 millimeters or under, and is capable of sustained rapid fire.
To riddle a target with machine gun fire.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
There is a small, square nub that protrudes off the right side which interfaces with the auto sear in a full auto gun.
That seems pretty clear, and for the following 30-plus years, the belief in the legality of DIAS possession was so prevalent that a variety of sources continued publicly selling drop-in auto sears that they claimed were manufactured before ATF's arbitrary cutoff date.
The court case dealt primarily with Drop-In Auto Sears (DIAS) for AR rifles, but the conclusions are much more far-reaching.
A large number of auto sears were registered for the FNC.
The banned accessory list includes "bump stocks, gatling triggers, drop-in auto sears and conversion kits." YouTube is also banning the promotion of high-capacity magazines that can carry more than 30 rounds.
In addition, it prohibited the sale of accessories such as bump stocks, gatling triggers, drop-in auto sears, conversion kits or any equipment that might "enable a firearm to simulate automatic fire or convert a firearm to automatic fire."