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Machinegun

Machinegun

For other uses of the phrase, see Machine gun (disambiguation). A machine gun is a fully automatic firearm that is capable of firing bullets in rapid succession. Such automatic weapons with a caliber of 20 mm or larger are generally referred to as autocannons.

Overview

autocannon Unlike semi-automatic firearms, which require one trigger pull per bullet fired, a machine gun is designed to fire bullets as long as the trigger is held down and ammunition is fed into the weapon. Although the term "machine gun" is often used to describe all fully-automatic weapons, in military usage the term is restricted to weapons designed to provide suppressive fire in continuous or frequent bursts of automatic fire for as long as ammunition lasts (however, a fully automatic firearm with a projectile caliber of equal to or greater than 20 mm (0.8 inch) is called an automatic cannon). Some machine guns have in practice maintained suppressive fire almost continuously for hours; other automatic weapons will eventually overheat, usually in less than a minute. Because they become very hot in operation, practically all machine guns fire from an open bolt, to permit air cooling from the breech between bursts. They also have either a barrel cooling system or removable barrels (so that a hot barrel can be swapped for a cool one.) Although subdivided into "light", "medium", "heavy" or "general purpose", even the lightest machine guns tend to be substantially larger and heavier than other automatic weapons. Squad automatic weapons (SAWs) are a variation of light machine guns and only require one operator (sometimes with an assistant to carry ammunition). Medium and heavy machine guns are either mounted on a tripod or on a vehicle; when carried on foot, the machine gun and associated equipment (tripod, ammunition, spare barrels) require additional crew members. The majority of machine guns are belt-fed, although some light machine guns are fed from drum or box magazines, and some vehicle-mounted machine guns are hopper-fed. Other automatic weapons are subdivided into several categories based on the size of the bullet used, and whether the cartridge is fired from a positively locked closed bolt, or a non-positively locked open bolt. Fully automatic firearms using pistol-caliber ammunition are called machine pistols or submachine guns (largely on the basis of size); selective-fire rifles firing a full-power rifle cartridge from a closed bolt are called automatic rifles, while those using a reduced-power rifle cartridge are called assault rifles. The machine gun's primary role in ground combat is to provide suppressive fire on an opposing force's position, forcing the enemy to take cover and reducing the effectiveness of his fire. This either halts an enemy attack or allows friendly forces to attack enemy positions with less risk. To this end, most light machine guns and general purpose machine guns are not designed for high accuracy, as would be expected of a rifle. Most are designed with a small degree of inaccuracy, referred to as the "cone of fire", because the rounds spread out as they travel towards the target area. Light machine guns usually have simple iron sights. A common aiming system is to alternate solid ("ball") rounds and tracer ammunition rounds (usually one tracer round for every four ball rounds), so shooters can walk the fire into the target and direct the fire of other soldiers. Assault rifles are a compromise between the pistol-caliber submachine gun and a traditional rifle firing a full-power cartridge, allowing single-shot, burst and full-automatic fire options. Many heavy machine guns, such as the M2 .50 caliber machine gun, are accurate enough to engage targets at great distances. During the Vietnam War, Carlos Hathcock set the record for a long-distance shot at 7382 ft (2250 m) with a .50 caliber heavy machine gun he had equipped with a telescopic sight. This led to the introduction of .50 caliber anti-material sniper rifles, such as the Barrett M82.

Components

All machine guns require the following components: # A feed system to load the firing chamber. Cartridges can be fed into the chamber by a variety of methods, the most common being spring-fed magazines or ammunition belts. # A trigger mechanism to fire the round. This includes the actual trigger, a trigger sear to catch the bolt, a bolt and a firing pin, as well as other components. Typically, the act of pulling the trigger causes something to strike the primer on the round in the chamber and disengages the sears. This allows continual cycling of the bolt until the trigger is released. A sear then grabs the bolt or firing pin. This stops the machine gun at some point in its cycle. # An extractor system to eject the spent or misfired cartridge. Usually this is fairly simple. A pin on the side of the bolt catches a ridge on the cartridge and flicks it out an ejection port. These components form a mechanism which must be powered by something. If powered by a spring absorbing the recoil of a fired cartridge, it is called recoil operated. If powered by the expanding gases of a fired cartridge, it is called gas actuated. If it powered by an external force, such as a motor, it is usually called a chain gun.

Operation

chain gun All machine guns follow a cycle:
- Removing the spent cartridge through an ejection port.
- Cocking the trigger mechanism so the weapon can be fired again.
- Loading the next round into the firing chamber. Usually spring tension or a cam forces the new round and bolt back into the firing chamber. A mechanism makes the firing pin fire the cartridge, activating the ejection and reloading steps. The cycle repeats. This full cycle takes a fraction of a second and can thus occur many times per second. The operation is basically the same, regardless of the means of activating these mechanisms. Some examples:
- Machine pistols and submachine guns (like the World War II "grease gun," MAC-10 or the Uzi) are usually blowback operated.
- Most assault rifles and squad automatic weapons are gas actuated. Some weapons, such as the AR-15/M16, integrate the piston with the bolt. Others, such as the M15 and AK patterns, attach the piston to a bolt carrier that unlocks and operates the bolt.
- A recoil-actuated machine gun uses the recoil to first unlock and then operate the action. Heavy machine guns, such as the M2 .50 and Browning .50, are of this type. These can be recognized by a large cocking lever needed to feed the first round.
- An externally actuated machine gun uses an external power source, such as an electric motor or even a hand crank to move its mechanism through the firing sequence. Most modern weapons of this type are called chain guns in reference to their driving mechanism. Gatling guns and revolver cannon have several barrels or chambers on a rotating carousel and a system of cams that load, cock, and fire each mechanism progressively as it rotates through the sequence. The continuous nature of the rotary action allows for an incredibly high cyclic rate of fire, often several thousand rounds per minute. Not all chain guns use multiple barrels or chambers, though. Chain guns are less prone to jamming than a gun operated by gas or recoil, as the external power source will eject misfired rounds with no further trouble. This is not possible if the force needed to eject the round comes from the round itself. Chain guns are generally used with large shells, 20 mm in diameter or more, though some, such as the M134 Minigun, fire smaller cartridges. They offer benefits of reliability and firepower, though the weight and size necessary for the driving mechanism makes them impractical for use outside of a vehicle or aircraft mount. Heavy machine guns are often water cooled or have interchangeable barrels, which must be changed periodically to avoid overheating. The higher the rate of fire, the more often barrels must be changed and allowed to cool. To minimize this, most air-cooled guns are fired only in short bursts or at a reduced rate of fire. Not all machine guns strike the primer in the same way. In blowback machine guns, the act of seating the round also fires the round. In gas operated and recoil-operated guns, a separate step in the firing sequence is needed to strike the round. In a progressive-fire gun, the firing pin is cycled by cams. In some automatic cannon, the primer is fired electrically. overheating In weapons where the round seats and fires at the same time, mechanical timing is essential for operator safety, to prevent the round from firing before it is seated properly. This is especially important in weapons like the 40 mm grenade launcher, where high explosives are present in the rounds being fired. Machine guns are controlled by one or more mechanical sears. When a sear is in place, it effectively stops the bolt at some point in its range of motion. Some sears stop the bolt when it is locked to the rear. Other sears stop the firing pin from going forward after the round is locked into the chamber. Almost all weapons have a "safety" sear, which simply keeps the trigger from engaging.

History

Multi-shot guns have a long development, going as far back to the 1st century, with plans for a multi-shot arrow gun by Greek engineer Hero of Alexandria. Leonardo Da Vinci devised plans for one in the 1400s, and stretching back to some of the earliest firearms and attempts at higher rates of fire, and some machine-gun-like traits happened as early as the 1700s. However, it would not be until the mid-1800s that successful machine-gun designs came into existence. Key characteristic of modern machine guns, their relatively high rate of fire and more importantly machine (automatic) loading, came with the Model 1862 Gatling gun, which was adopted by the United States Navy. These weapons were still powered by hand; however, this changed with Hiram Maxim's idea of harnessing recoil energy to power reloading in his Maxim machine gun. Dr. Gatling also experimented with electric-motor-powered models; this externally powered machine reloading has seen use in modern weapons as well. The Vandenburg and Miltrailleuse volley (organ) gun concepts have been revived partially in the early 21st century in the form of electronically controlled, multibarreled volley guns. It is important to note that what exactly constitutes a machine gun, and whether volley guns are a type of machine gun, and to what extent some earlier types of devices are consider to be like machine guns, is a matter of debate in many cases and can vary depending which language and exact definition is used.

Early rapid-firing weapons

Among first known ancestor of multi-shot weapons was created by James Puckle, a London lawyer, who patented what he called "The Puckle Gun" on May 15, 1718. It was a design for a 1 in. (25.4mm) caliber, flintlock semi-automatic cannon able to fire 9 rounds before reloading, intended for use on ships. According to Puckle, it was able to fire round bullets at Christians and square bullets at Turks. While ahead of its time, foreshadowing the designs of revolvers, it was not adopted or produced. ship In the early and mid-19th century, a number of rapid-firing weapons appeared which offered multi-shot fire, and a number of semi-automatic weapons as well as volley guns. Volley guns (such as the Mitrailleuse) and double barreled pistols relied on duplicating all parts of the gun. Pepperbox pistols did away with needing multiple hammers but used multiple barrels. Revolvers further reduced this to only needing a pre-prepared magazine using the same barrel and ignitions. However, like the Puckle gun, they were still only semiautomatic. The coffee-mill gun of the Civil War featured both automatic loading and single barrel, only separated functionally from the modern machine gun by being hand-powered rather than using cartridges. The Gatling gun, patented in 1861 by Richard Jordan Gatling, was the first to offer controlled, sequential automatic fire with automatic loading. The design's key features were machine loading of prepared cartridges and a hand-operated crank for sequential high-speed firing. It first saw very limited action in the American Civil War and was subsequently improved. Many were sold to other armies in the late 1800s and continued to be used into the early 1900s, until they were gradually supplanted by Maxim guns. The Gatlings were the first widely used rapid-fire guns and, due to their multiple barrels, could offer more sustained fire than the first generation of air-cooled, recoil-operated machine guns. The weight, complexity, and resulting cost of the multibarrel design meant recoil-operated weapons, which could be made lighter and cheaper, would supplant them. It would be another 50 years before the concept was again used to allow extremely high rates of fire, such as in chain guns, miniguns, and automatic aircraft cannons.

Maxim gun

minigun The first true machine gun was invented in 1883 by Hiram Maxim. The "Maxim gun" used the recoil energy of the previously fired bullet to reload rather than being hand powered, enabling a much higher rate of fire than was possible using earlier designs. Maxim's other great innovation was the use of water cooling (via a water jacket around the barrel) to reduce overheating. Maxim's gun was widely adopted and derivative designs were used on all sides during the First World War. The design required less crew, was lighter, and more useable than earlier Gatling guns. Heavy guns based on the Maxim such as the Vickers machine gun were joined by many other machine weapons, which mostly had their start in the early 20th century. Submachine guns (e.g., the Thompson, or "Tommy gun") as well as lighter machine guns (the BAR, for example) saw their first major use in WW1, along with heavy use of large-caliber machine guns. The biggest single cause of casualties in WW1 was actually artillery, but combined with wire entanglements, machineguns earned a fearsome reputation. The automatic mechanisms of machine guns were applied to handguns, giving rise to automatic pistols (and eventully machine pistols) such as the Borchardt (1890s) and later submachine guns (such as the Beretta 1918). Machine guns were mounted in aircraft for the first time in World War I. Firing through a moving propeller was solved in a variety of ways, including the interrupter gear, metal reinforcement of the propeller, or simply avoiding the problem with wing-mounted guns or having a pusher propeller. During the interwar years, many new designs were developed, such as the Browning .50 caliber (12.7mm) in 1933, which, along with others, were used in World War II. The trend toward automatic rifles, lighter machine guns, and more powerful submachine guns resulted in a wide variety of firearms that combined characteristics of an ordinary rifle and a machine guns. The Cei-Rigotti (1900s), Federov Avtomat (1910s), AVS-36 Simonov (1930s), MP44, M2 Carbine, AK-47, and AR-15 have come to be known as assault rifles (after the German term sturmgewehr). Many aircraft were equipped with machine cannons, and similar cannon (nicknamed "Pom-pom guns") were used as antiaircraft weapons. The designs of Bofors of Sweden were widely used by both sides and have greatly influenced similar weapons developed since then.

Modern era

The Cold War era saw mostly a refinement of weapon types in the form of lower weight and higher reliability. The semiautomatic rifles of World War II vintage were almost totally replaced by lighter assault rifles such as the M-16 and Soviet AK-74. Infantry adopted general-purpose machine guns like the American M-60 for squad use, using air cooling for lighter weight. Heavy machine guns were retained for ground vehicles and fortifications. For aircraft use, even heavy machine guns proved to lack killing power in the air-to-air role, and by the late 1950s fighter aircraft armament had almost totally switched to automatic cannons. Machine guns, with lower recoil, remained popular for helicopters and for ground attack aircraft, supplemented by new Gatling-style, electric multibarrel weapons like the American Minigun. In police, special operations, and other paramilitary roles, smaller automatic weapons, including light submachine guns and machine pistols, proliferated, many relying on the increasingly ubiquitous 9x19 mm round.

Future

machine pistols Conventional machine-gun development has been slowed by the fact that existing machine-gun designs are adequate for most purposes, although significant developments are taking place with regard to antiarmor and antimissile weapons. In the future, electronically controlled machine guns with ultrahigh rates of fire may see use in some applications, although current small-caliber weapons of this type have found little use: they are too light for anti-vehicle use, but too heavy (especially with the need to carry a tactically useful amount of ammunition) for individual soldiers. The trend towards higher reliability and lower mass for a given power will likely continue. The newest machine-gun designs center around the Personal Defense Weapon concept, a cross between a submachine gun and a sidearm that is useful for support personnel who need a small, concealable weapon that keeps their hands free yet provides massed firepower when needed—roles such as security teams in occupation zones. A precursor is the now-popular FN P90. The Pentagon is also working on a next-generation infantry weapon under the Objective Individual Combat Weapon program, the ultimate aim of which is to combine a lightweight carbine with an airburst grenade launcher, potentially improving the effectivity of an individual soldier manyfold. The XM29 received much attention as a prototype developed under this program, but was for various reasons, including high cost as well as weight and bulk considerations, eventually deemed unsatisfactory. The OICW program has since been split into several increments, each intended to bring the vision of a combined kinetic energy rifle and airburst grenade launcher one step closer to reality.

External links

- [http://people.howstuffworks.com/machine-gun.htm How Stuff Works] - Very well written article with animated diagrams
- [http://inventors.about.com/library/inventors/blgun.htm Gun history]
- -- A patent for an early automatic cannon
- [http://www.vickersmachinegun.org.uk/ Vickers Machine gun site]
- [http://www.nazarian.no/wepc.asp?lang=0&group_id=13 Nazarian's Gun's Recognition Guide on Machine Guns]
- [http://www.rememuseum.org.uk/arms/technote/armtech4.htm The REME Museum of Technology - machine guns] Category:Firearms
- ja:機関銃

Machine gun (disambiguation)

Machine gun could refer to:
- The weapon; see machine gun.
- Machine Gun is the name of a free jazz album by Peter Brötzmann as well as the New York based improvising band Machine Gun which featured Thomas Chapin and Sonny Sharrock.
- The song by Jimi Hendrix; see Band of Gypsys.

Automatic firearm

] An automatic firearm is a firearm that will continue to load and fire ammunition as long as the trigger (or other activating device) is pressed or until it runs out of ammunition. The M2 machine gun, the M60 machine gun and the M134 Minigun are examples of full-automatic weapons, as are the autocannon mounted on many military aircraft and used in other applications such as anti-aircraft defense. Although automatic firearms (by definition) are capable of full-automatic fire, most also have a selective fire capability, meaning that they can be used as a semi-automatic firearm generally by manipulating a selector switch (as with the M16), or by pressing the trigger further to the rear, as with the Steyr AUG assault rifle. So-called "automatic" pistols, however, are actually semi-automatic in operation, firing a single shot for each trigger press, automatically ejecting the spent cartridge and loading a fresh one into the chamber. Though they are correctly referred to as "automatic pistols", the nature of their action is, in fact, semi-automatic and that distinction is necessary for description in the popular press. Full-automatic weapons tend to be restricted to military and police personnel in most developed countries. In the United States, machine guns registered after 1986 have been off the public market since the Firearm Owners Protection Act of 1986. See gun control.

Types of Automatic Firearms

- Assault rifle
- Autocannon
- General purpose machine gun
- Heavy machine gun
- Light machine gun
- Machine gun
- Machine pistol
- Medium machine gun
- Squad automatic weapon
- Submachinegun

Patents

- - Automatic gun Category:Firearm actions

Caliber

The word calibre (British English) or caliber (American English) designates the interior diameter of a tube or the exterior diameter of a wire or rod. It comes from the Italian calibro, itself from the Arabic quâlib, meaning mould. The term most often appears with respect to firearms, as a measure of the size of the barrel; however, it also has use in other fields.

Firearms

In firearms, the caliber is the diameter of the inside of the barrel. In a rifled barrel the distance is measured between the lands. The measurement is in inches and the caliber (abbreviated to cal) is quoted as a fraction (hundredths or thousandths) of an inch, so a 0.22 inch smallbore rifle is .22 cal. Outside Great Britain and the U.S., the caliber of a weapon is commonly expressed in millimeters (mm). The caliber of a weapon is often informally used to describe certain common weapons. A .45 cal pistol is called a '45', a 9 mm semi-automatic pistol is called a '9 mil', a .380 caliber is called a '380', etc. This gives rise to the impression that "cal" is a unit of measurement, equal to 1/100 or 1/1000 of an inch, whereas it is rather a figure of speech. For historical reasons, the name of a cartridge is not always the actual caliber. As one example, the common .38 Special revolver actually fires a bullet 0.357 inches in diameter. Note that caliber alone is not a good indicator of the terminal ballistics (commonly refered to as "stopping power") of a cartridge towards an organic target. Bullet weight and shape, powder capacity of the cartridge, and length of the barrel are some of the many variables which also have an effect. Small arms range in bore size from approximately .177 cal up to .50 cal. Arms used to hunt big game may be as large as .800 caliber. In the middle of the 19th century, muskets and muzzle-loading rifles were .58 cal or larger.

Caliber as measurement of length

rifle The length of the barrel (especially for larger guns) is often quoted in calibers. The effective length of the barrel (from breech to muzzle) is divided by the barrel diameter to give a value. As an example, the main guns of the Iowa class battleships can be referred to as 16"/50 caliber. They are 16 inches in diameter and the barrel is 800 inches long (16
- 50 = 800). This is also sometimes indicated using the prefix L/, so for example, the most common gun for the Panzer IV tank is described as a "75 mm L/48", meaning a barrel 75 mm in diameter, and 3600 mm long.

Alternative measurements of bore

Measurement of the bore of large weapons can be, and often was, expressed in pounds. A sphere of lead of the same diameter as the bore would have a certain weight. Lead is a useful material because it is malleable though unsuited for large projectiles because of its density. This leads to certain guns being referred to as 6-pounder, 25-pounder, et cetera. However this relationship between calibre and projectile weight changed with the introduction of the cylindrical rifled shell. The gun continued to be named by the weight of projectile it threw although this no longer gave any indication of the barrel size.

Other uses

In architecture, the caliber of a column is its diameter. In electricity, the caliber of an instrument of measure is the maximum value it can measure. In nautical parlance, the caliber of a chain is the diameter of the metal rod used to make each chain link. Agricultural produce is also often ranked by caliber (diameter), for instance olives, peas or eggs. In typography, the caliber of a font designates the size of the eye of a character, neglecting any risers or descenders. In horology, the term is used to distinguish the size and type of movement used within a timepiece.

Autocannon

.]] An autocannon is a projectile weapon with a larger bore size than a machine gun, and a faster rate of fire than regular cannon used by artillery units. The term cannon was used during WWII to describe guns used in aircraft, where the distinction was that the shells were explosive. After the war similar guns were used with non-explosive rounds in the anti-tank role, and the name autocannon started to become popular. Autocannon today are typically distinguished by their incorporation of some method of automated loading and firing. Examples of an autocannon are the 25 mm M242 Bushmaster mounted on the M2 Bradley, the Bofors 40 mm anti-aircraft gun, or the 30 mm GAU-8 in the A-10 Warthog close air support airframe. Several tank guns have auto loading systems, and can be considered autocannon even though they are large-bore, up to 125 mm. Soviet and Russian armor, especially their main battle tanks, have used autoloaders extensively for many tank generations, even as US tanks keep human gun loaders. The French Leclerc also uses an automated 120mm gun. Typically, these are not commonly referred to as autocannon, but instead as tank guns. Category:Automatic cannons ja:機関砲

Trigger

:For other meanings, see Trigger (disambiguation). In its earliest usage, trigger refers to a mechanical mechanism, the pulling or pushing of which sets a device into action. This includes the lever that sets off the chain of events that fires a gun, the release mechanisms on a crossbow, or the lever that engages an animal trap. Today trigger is also used in a wider sense to refer to a precipitating cause of some event. The "trigger" (noun) is said to "trigger" (verb) the event. Note that, in this wider sense, "trigger" need not be a necessary condition for the event. To the extent that it is a sufficient condition, this is only relative to some implied background conditions taken as given. (See necessary and sufficient conditions.) Examples of triggers:
- If one adds a seed crystal to a supersaturated solution, the crystal will "trigger" the precipitation of the dissolved material.
- In the almost clichéd idea of a butterfly flapping its wings and thereby causing a great weather disturbance (see chaos theory), the butterfly can be said to have "triggered" the disturbance.
- An event which causes an allergic reaction, for example, exposure to cat dander may trigger an asthma attack in an allergic person.
- A reminder in persons with post-traumatic stress disorder which can be either passive exposure to a specific visual/tactile/other sensual "image" resembling a part from the trauma experience, or an active body movement stored in procedural memory from the abusive "training", which triggers the PTSD symptoms (for example, outrage, despair, fear, or obsessive thoughts...)
- In computer programming, software may be set up to be event driven, so that certain events (e.g. an insert, an update or a delete of a database) trigger the invocation of particular procedures. See Database trigger.
- In ethology, a trigger is a cue in the environment that causes the "release" of a (genetically predetermined) behavior. An example is the pecking behavior of young Herring gulls, elicited by a red spot on the beak of a parent. In this context, the trigger is also referred to as an eliciting stimulus.
- The use of the term trigger for oscilloscopes is explained in the relevant article.
- A Schmitt trigger is an electronic circuit.
- In business, a trigger point is a situation in which the level of stock holdings of a hostile bidder triggers anti-takeover provisions.
- In a particle physics detector, a trigger system uses simple criteria to rapidly decide which events to keep when only a few can be recorded. For an example of how this is integrated into a detector, see ATLAS trigger system.
- electronic drummers utilize piezoelectric transducers in trigger pads to produce waveforms in a sound module or a MIDI controller, which result in percussion instrument sounds.

Caliber

Firearms

Caliber as measurement of length

Alternative measurements of bore

Other uses

Automatic cannon

Open bolt

A semi or fully-automatic firearm which is said to fire from an open bolt is one where, when ready to fire, the bolt and working parts are held to the rear. When the trigger is pulled the bolt goes forward, feeding a round from the magazine into the chamber and firing it. Like any other self-loading design, the action is cycled by the energy of the shot; this sends the bolt back to the rear, ejecting the empty cartridge case are preparing for the next shot. Compared to a closed bolt design, open bolt weapons generally have fewer moving parts. The firing pin is usually part of the bolt, saving on manufacturing costs. Having an open chamber while not firing also helps keep the weapon cooler. However, accuracy suffers due to movement of heavy parts prior to firing, and lack of full lock up between bolt and barrel.

Open bolt weapons

- Uzi
- Sten
- Sterling
- M249
- MG42
- M240
- MG34
- M60
- MP40
- Thompson

Mixed mode weapons

- FG42

Notes

In the U.S., the ATF have a policy whereby they consider semi-automatic open bolt weapons to be readily convertible to fully-automatic fire, therefore they are classed and controlled as fully-automatic weapons.

Light machine gun

at Babadag Range, Romania, on July 15, 2000]] A light machine gun (LMG) is a categorization type, or class of machine guns that are generally lighter than other of machine guns of its period, and usually designed to be carried by an individual soldier, but sometimes with an assistant. In practice, they are either automatic rifles (machine rifles) or medium machine guns with a bipod, a stock, and sometimes a pistol grip. Modern light machine guns are often lighter caliber, in addition to being lighter weight. Usually an LMG, or LMG version of a firearm is intended to act as a support weapon in that it can generate a greater volume of continuous fire than the usual firearms carried by infantry soldiers, but at the cost of greater weight and higher ammunition consumption. While it is usually possible to fire an LMG "from the hip" or on the move, they are much more accurate when fired from a prone position, especially when using a bipod. They are often designed to be used with magazines, not belts, but some, such as the M249, use both. Light machine guns are often used as squad automatic weapons.

Examples

These were either exclusively LMG's, or had a LMG version.
- Madsen machine gun
- M1909 Benet-Mercie (.30-06)
- ZB vz.26 (7.92mm x 57mm
- Bren (L4) machine gun
- Chauchat machine gun
- Lewis machine gun
- RPD (7.62 x 39 mm)
- RPK (7.62 x 39 mm)
- RPK-74 (5.45 x 39 mm)
- Brno series
- M249 (5.56mm)
- Colt Automatic Rifle (5.56mm)

Belt (firearm)

training manual]] rounds are draped over the tree]] A belt is an ammunition-feeding device for a firearm, typically a machine gun. It holds a single row of cartridges adjacent to each other. The belt serves to link the cartridges together so that they may be fired in a uniform manner. In general, the belt is either permanently linked, fed through the weapon, and subsequently pushed out the other side of the chamber, or the links themselves "disintegrate", or break apart after firing, as the cartridges are integral to the design of the belt. The latter is called a "disintegrating belt". The main advantage of the non-disintegrating belt is that it is refillable. The advantages of the disintegrating belt are that it is lighter and does not dangle from the other side of the gun. One well-known weapon that uses a belt-feeding mechanism is the American M60 machine gun, although adaptations have been made for the M16 rifle as well, which allow it to be fed from a belt. Belts are useful in that long sequences of ammunition can be run through a weapon with little to no interaction from the individual firing it. They generally help prevent jamming and provide a controlled entry and exit from the firearm. Belts are often stored in a transportation box, which can be attached under the firearm. This allows mobile infantry troops equipped with light and medium machine guns to carry a large amount of ammunition with ease of transportation that would not be allowed by a loose belt.

Magazine (firearm)

A magazine (also called a mag) is an ammunition storage device within or attached to a firearm. The magazine may be integral to the firearm (fixed) or removable (detachable). The cartridges in the magazine are loaded into the firearm either automatically or manually depending on the type of gun, but almost always by a spring. Some magazines can in turn be loaded by a clip; contrary to the common misconception, 'clip' and 'magazine' are not synonymous. An example of this misuse is the use of 'banana clips' to refer to curved box magazines, although this particular phrase is not as common as the more proper 'banana magazine'. The most common type of magazine is the detachable "box" type (pictured at right). However, other types are available, such as the "drum" magazine, sometimes used with the Thompson submachine gun, the "pan" magazine of the Russian DP-28 machine gun, and the fixed "tube" magazine found on many lever-action rifles and pump-action shotguns. Magazines for a particular firearm may come in different shapes and sizes. Certain magazines are unmistakable in their appearance, such as those of the AK-type assault rifles, while with others it can be more difficult to tell what gun they belong to, such as when comparing the Ruger Mini-14's magazines with AR-15/M16 magazines. Category:Firearm components

Cartridge (weaponry)

A cartridge or round packages the bullet, gunpowder and primer into a single metallic case precisely made to fit the firing chamber of a firearm. The primer is a small charge of impact-sensitive chemical that may be located at the center of the case head (centerfire ammunition) or at its rim (rimfire ammunition). Electrically-fired cartridges have also been made; see below. A cartridge without a bullet is called a blank.

Design

blank

The cartridge seals a firing chamber in all directions except down the bore. A firing pin strikes the primer, igniting it. The spark from the primer ignites the powder. Burning gases from the powder expand the case to seal against the chamber wall. The projectile is then pushed in the direction that releases this pressure, down the barrel. After the projectile leaves the barrel the pressure is released and the cartridge case is pulled out of the chamber. Critical specifications include its caliber, bullet weight, expected velocity, maximum pressure, headspace, overall length and primer type. The diameter of a bullet is measured either as a decimal fraction of an inch, or in millimeters. The length of a cartridge case may also be designated in millimeters. Where two numbers are together, the first is typically the diameter of the barrel's lands (or sometimes the diameter of the bullet itself), and the second is the length of the cartridge case. For example, the 7.62 x 51 mm uses a bore diameter of 7.62 mm and has an overall case length of 51 mm. Most high-powered guns have relatively small bullets moving at high speeds. This is because bullet energy increases proportionately to bullet weight and as the square of velocity. Therefore, a bullet going twice as fast has four times the energy (see physics of firearms). Bullet speeds are now limited by starting bore pressures, which in turn are limited by the strength of materials and the weight of gun people are willing to carry. Larger cartridges have more powder, and usually higher velocities. The lethality of pistol ammunition is not limited by the ammunition, but by the accuracy and doctrine of the shooter. Rounds with these energies have insufficient momentum to knock people down (the recoil would break wrists), and move too slowly to cause significant hydrostatic shock.

Centerfire

Of the hundreds of different designs and developments that occurred, essentially only two basic differences remain. All current (civilian) firearms are either rimfire or centerfire. The military is still trying to perfect electrical firing, which does away with the primer. Centerfire uses a centrally located primer, which, in most cartridges used by civilians, can be replaced, so that the expensive brass cartridge cases can be reused. This is called Boxer primed. The military uses a very similar system, called Berdan priming, which is fractionally cheaper, but prevents the case from being easily re-used. With care, they can be reloaded, however, and are easier for guerillas/terrorists to reload, as the new "primer" can be as simple as a bit of tin can and a match head, unlike the multi-stage process required for making a boxer primer.

Rimfire

Rimfire, of which only the popular .22 LR remains in common use, was a popular solution before the centerfire design was fully perfected. It can only be used for fairly low powered cartridges, as the case has to be soft enough to be deformed by the firing pin, which detonates the priming compound in the rim. In the past, 9 mm cartridges were available, as well as .177, .25, etc. cartridges. BB and CB caps were common, as well as .22 Short and .22 Long. Today, .22 LR (Long Rifle) easily accounts for over 99% of all rimfire ammunition shot. Recently, a .177 rimfire cartridge was released, but whether it catches on is another matter. Rimfire rounds are normally a soft lead bullet, and can be supersonic or subsonic. They are often gilded with copper to try to keep lead off the hands of the shooter, since it is a low-level poison.

Cartridges in use

copper There is great variety in the length and diameter of cartridges for the different kinds and calibres of rifles and pistols. The best cartridge for different purposes is subject to much discussion. However there are standard uses for certain calibres, and these are a reliable guide to recommended uses. It is important to note that equivalent caliber is by no means equivalent power. Generally speaking, "stopping power" is determined by the weight of the bullet, the terminal ballistics of the bullet -- does it stay straight and in one piece, tumble, or "mushroom" on impact -- and the charge of gunpowder accelerating it. For example, a .22 pistol round is almost exactly the same caliber as a .223 Remington (5.56 x 45 mm NATO) rifle round, but the .223 is vastly more powerful. The following list samples only a few very well-known cartridges; for a complete list, see List of cartridges (weaponry), pistol and rifle. The list is roughly ordered by cartridge power.
- .22 Long Rifle or .22LR cartridge is used for target shooting and hunting. Despite the name, it is used in some target pistols.
- 9 mm can refer to a variety of pistol cartridges, but most commonly it means 9 x 19 mm "Luger" or "Parabellum". It is used in a variety of automatic handguns and submachine guns, though law enforcement and military users are moving away due to its poor penetration against body armor.
- 7.62 x 39 mm cartridges are used in the Kalashnikov AK-47. This is the most fired cartridge in history. Kalashnikov did not invent the "medium power" automatic rifle cartridge, but it brought the concept into practical mass-production.
- 5.56 x 45 mm is NATO's standard assault rifle and light machine gun cartridge. It is a military adaptation of the .223 Remington.
- 7.62 x 51 mm is NATO's standard sniper rifle and medium machine gun cartridge. In the 1950's it was the standard NATO cartridge for rifles, but recoil and weight proved problematic for the new assault rifles designs such as the FN FAL. It is itself derived from:
- .30-06, (approx 7.7 mm) the standard US Army rifle cartridge for the first half of the 20th century. It is a "full-power" rifle cartridge suitable for hunting medium sized game. It was most famously used in the M1 Garand semi-automatic rifle.
- .50 Browning Machine Gun is used in heavy machine guns and super-high-powered sniper rifles by NATO armies. Such rifles are intended for destroying military matériel such as sensitive parts of helicopters and aircraft. Civilian enthusiasts use them for long-distance target-shooting. : See also: List of cartridges (weaponry), pistol and rifle

History

The original cartridge for military small arms dates from 1586. It consisted of a charge of powder and a bullet in a paper tube. Thick paper is still known as cartridge paper from its use in these cartridges. This cartridge was used with the muzzle-loading military firearm, the base of the cartridge being ripped or bitten off by the soldier, the powder poured into the barrel, and the bullet then rammed home. Before the invention of the firelock or flint-lock, about 1635, the priming was originally put into the pan of the wheel-lock and snaphance muskets from a flask containing a fine-grained powder called serpentine powder. Later the pan was filled from the cartridge above described before loading. The mechanism of the flint-lock musket, in which the pan was covered by the furrowed steel struck by the flint, rendered this method of priming unnecessary, as, in loading, a portion of the charge of powder passed from the barrel through the vent into the pan, where it was held by the cover and hammer. The next important advance in the method of ignition was the introduction of the copper percussion cap. This was only generally applied to the British military musket (the Brown Bess) in 1842, a quarter of a century after the invention of percussion powder and after an elaborate government test at Woolwich in 1834. The invention which made the percussion cap possible was patented by the Rev. A. J. Forsyth in 1807, and consisted of priming with a fulminating powder made of chlorate of potash, sulphur and charcoal, which exploded by concussion. This invention was gradually developed, and used, first in a steel cap, and then in a copper cap, by various gunmakers and private individuals before coming into general military use nearly thirty years later. The alteration of the military flint-lock to the percussion musket was easily accomplished by replacing the powder pan by a perforated nipple, and by replacing the cock or hammer which held the flint by a smaller hammer with a hollow to fit on the nipple when released by the trigger. On the nipple was placed the copper cap containing the detonating composition, now made of three parts of chlorate of potash, two of fulminate of mercury and one of powdered glass. The detonating cap thus invented and adopted, brought about the invention of the modern cartridge case, and rendered possible the general adoption of the breech-loading principle for all varieties of rifles, shot guns and pistols. Probably no invention connected with firearms has wrought such changes in the principle of gun construction as those effected by the "expansive cartridge case." This invention has completely revolutionized the art of gunmaking, has been successfully applied to all descriptions of firearms, and has produced a new and important industry -- that of cartridge manufacture. Its essential feature is the prevention of all escape of gas at the breech when the weapon is fired, by means of an expansive cartridge case containing its own means of ignition. Previous to this invention shot guns and sporting rifles were loaded by means of powder flasks and shot flasks, bullets, wads and copper caps, all carried separately. The earliest efficient modern cartridge case was the pin-fire, patented, according to some authorities, by Houiller, a Paris gunsmith, in 1847; and, according to others, by Lefaucheux, also a Paris gunsmith, in or about 1850. It consisted of thin weak shell made of brass and paper which expanded by the force of the explosion, fitted perfectly into the barrel, and thus formed an efficient gas check. A small percussion cap was placed in the middle of the base of the cartridge, and was exploded by means of a brass pin projecting from the side and struck by the hammer. This pin also afforded the means of extracting the cartridge case. This cartridge was introduced in England by Lang, of Cockspur Street, London, about 1855. The central-fire cartridge was introduced into England in 1861 by Daw. It is said to have been the invention of Pottet of Paris, improved upon by Schneider, and gave rise to much litigation in respect of its patent rights. Daw was subsequently defeated in his control of the patents by Eley Bros. In this cartridge the cap in the centre of the cartridge base is detonated by a striker passing through the standing breech to the inner face, the cartridge case being withdrawn, or, in the most modern weapons, ejected by a sliding extractor fitted to the breech end of the barrel, which catches the rim of the base of the cartridge. This is practically the modern cartridge case now in universal use. In the case of shot guns it has been gradually improved in small details. The cases are made either of paper of various qualities with brass bases, or entirely of thin brass. The wadding between powder and shot has been thickened and improved in quality; and the end of the cartridge case is now made to fit more perfectly into the breech chamber. These cartridges vary in size from 32 bore up to 4 bore for shoulder guns. They are also made as small as .410 and .360 gauge: their length varies from 1¾ to 4 inches (44 to 102 mm). Cartridges for punt guns are usually 1½ inches (37 mm) in diameter and 9¾ inches (248 mm) in length. In the case of military rifles the breech-loading cartridge case was first adopted in principle by the Prussians about 1841 in the needle-gun breech-loader. In this a conical bullet rested on a thick wad, behind which was the powder, the whole being enclosed in strong lubricated paper. The detonator was in the hinder surface of the wad, and fired by a needle driven forward from the breech, through the base of the cartridge and through the powder, by the action of a spiral spring set free by the pulling of the trigger. In 1867 the British war office adopted the Eley-Boxer metallic central-fire cartridge case in the Enfield rifles, which were converted to breech-loaders on the Snider principle. This consisted of a block opening on a hinge, thus forming a false breech against which the cartridge rested. The detonating cap was in the base of the cartridge, and was exploded by a striker passing through the breech block. Other European powers adopted breech-loading military rifles from 1866 to 1868, with paper instead of metallic cartridge cases. The original Eley-Boxer cartridge case was made of thin coiled brass. Later the solid-drawn, central-fire cartridge case, made of one entire solid piece of tough hard metal, an alloy of copper, &c., with a solid head of thicker metal, has been generally substituted. Central-fire cartridges with solid-drawn metallic cases containing their own means of ignition are almost universally used in all modern varieties of military and sporting rifles and pistols. Around 1970, machined tolerances had improved to the point that the cartridge case was no longer necessary to seal a firing chamber. Precision-faced bolts would seal as well, and could be economically manufactured.

Problems

The conventional cartridge also adds certain problems to the gun. Also, it had become well-known that the cartridge is both expensive and heavy, and the single most difficult part to manufacture. Generally, they were manufactured by deforming a disk of brass with a series of progressive dies. Cases are generally round, and this decreases the volumetric efficiency of the gun's magazine. A caseless cartridge can have the propellant molded in a square shape. The gun has to have an ejection port to eliminate the spent cartridge-case. This means that dirt and fluid can enter the gun through the ejection port. The primer, and associated firing pin add a delay between the time the trigger is pressed and the time the bullet leaves the barrel. Experiments had decisively demonstrated that this delay reduced accuracy for most shooters. A popular accessory, available for many guns, were "low mass" firing pins and hammers, often made of titanium, that would reduce the time to fire the percussion cap. On the flip side, the case helps carry heat away from the firing chamber.

Reloading

Some shooting enthusiasts reload their spent brass cartridges. By using a press and a set of dies, one can reshape, deprime, reprime, recharge the case with gunpowder, and seat and crimp a new bullet. One can do this at about half the cost of purchasing factory ammo. It also allows one to use different weights and styles of bullets, as well as varying the powder charge which affects accuracy and power. Enthusiasts usually only reload boxer primed cartridges as the process is more easily automated than berdan priming.
:See: Handloading.

Caseless ammunition

:Main article: Caseless ammunition Around 1989, Heckler & Koch, a prominent German firearms manufacturer, began making press releases about the G11 assault rifle, which shot a 4.75x33 square caseless round. The round was mechanically fired, with an integral primer. In 1993 Voere of Austria began selling a gun and caseless ammunition. Their system used a primer, electronically-fired at 17.5 ± 2 volts. The upper and lower limits prevent fire from either stray currents or static electricity. The direct electrical firing eliminates the mechanical delays associated with a striker, reducing reaction time and allowing for easier adjustment of the rifle trigger. In both cases, the "case" was molded directly from solid nitrocellulose, which is itself relatively strong and inert. The bullet and primer were glued into the propellant block.

External links

- [http://www.cartridgecollectors.org/glossary.htm Cartridge Collectors] Category:Ammunition ja:実包

Open bolt

Open bolt weapons

- Uzi
- Sten
- Sterling
- M249
- MG42
- M240
- MG34
- M60
- MP40
- Thompson

Mixed mode weapons

- FG42

Notes

Submachine gun

A submachine gun is a firearm that combines the automatic fire of a machine gun with the ammunition of a pistol, and is usually between the two in weight and size. They were first experimented with in the form of stocked pistols being turned fully automatic in the late 1800s and early 1900s. The first dedicated designs were developed in the latter stages of WWI both as improvement on earlier stocked pistols, and to offer an advantage in trench warfare. They rose to prominence as a front-line and commando weapon during WWII, and are now widely used by police and paramilitary organizations. They are ideal for close-range combat in enclosed urban environments, where a weapon's range and accuracy is less important than the ability to easily and instinctively spray a target with bullets. They were also popularized in the 1920's and 30's as weapon of choice of gangsters. Submachine guns lack long-range power and accuracy compared to higher power rifles, limiting their use in the open. Stocked automatic weapons firing pistol rounds were developed around the same time during World War One, by Italy, Germany, and the U.S.

History

gangster The submachine gun (sometimes abbreviated SMG) appeared during the later stages of WWI and was a product of trench warfare. By 1918 fighting in the trenches had become a clumsy and brutal art, involving grenades, pistols, sharpened entrenching tools, and bayonets. The Italians were the first to have a submachine gun in the war, the Beretta 1918, which beat the Bergman MP18 by a couple of months to service in 1918. It had a traditional wooden stock, a 25 round box magazine, and fired at 900 rounds per minute. Its development was aided by the Villar Perosa (introduced in 1915), sometimes called the first SMG because it fired a 9mm pistol round; originally intended as a aircraft weapon, it also saw use by infantry, as an LMG. The Germans had been using heavier versions of Luger pistols, equipped with larger capacity snail magazine, and longer barrel; these were semi-automatic. A stocked purposed designed automatic pistol was worked on by Bergmann, which by 1918 had developed the MP18. The MP18 was used in large numbers by the stormtroopers which, in conjunction with appropriate tactics, achieved some notable successes in the final year of the war. They were not enough to prevent Germany's collapse in November 1918. The Thompson SMGs had been in development at the same time and even earlier as the Bergman and Beretta, but development was put on hold in 1917, when the US and the weapon's designer entered the war. The design was completed afterwards and used a different internal system from the MP18 or Beretta, but it had missed its chance to be the first purpose-designed SMG to enter service. It would however go on to serve as the basis for later weapons and have the longest active service life of the three. In the inter-war years the submachine gun became notorious as a gangster weapon; the iconic image of zoot-suited James Cagney types wielding drum-magazine Thompson SMGs (often called "Tommy gun") caused some military planners to shun the weapon. It was also used by the police, and many criminals favored the BAR, It was nevertheless gradually accepted by many militaries, with many countries developing their own designs over the period, especially in the 1930's. In the USSR, the PPD34 and PPD34/38, were developed. In France the MAS 35 was developed into the MAS 38. In Germany some improvements on the MP18 were employed, namely the MP28/II and the MP34. Also, Nazi Germany adopted the MP38, unique in that it used no wood and a folding metal stock, though it used similar amount of stampings as the MAS. Italy further developed a number of its own designs (see List of Italian submachine guns), with similar attempts at improvements in lower production cost, quality, or weight. List of Italian submachine guns During the invasion of Poland by Nazi Germany in 1939, the MP38 production was still just starting and only a few thousand were in service, but it proved very popular especially in towns and cities. From it, the nearly identical, but safer and cheaper to make, MP40 was developed; about a million MP40's were made in WW2. The MP40's design used even more stampings, and less important metals such as aluminium, but still managed to be lighter because it avoided some of the heavier machined parts of the MP38. Britain adopted the Lanchester submachine gun, based on the MP28/II. However the cost of manufacture was and rate of production led to the much simpler, cheaper and faster to make Sten guns. The Sten was so cheap to make that near the end of WWII, Nazi Germany made a few thousand of a copy of the design. Britain also used many M1928 Tommy Guns early on (the one of the intra-war period with a drum magazine), and also many of the improved version M1 (the one seen only with a stick magazine). After the war, the Sten would be replaced by the Sterling submachine gun. America and its allies used the Thompson SMG, especially the simplified M1 version that did away with the Tommy's drum magazine and some of the machined parts. Because it was still expensive to produce, the M3 "Grease Gun" was adopted in 1942, followed by the slightly improved M3A1 in 1944. The M3 was not necessarily more effective, but was made with cheap stamped metal, making it much more affordable. It could be configured to fire either .45 ACP ammunition, which the Thompson and M1911 pistol also fired, or the 9 mm Parabellum, widely used by Allies and Axis. It would be among the longest serving of the SMGs designed during the war, being produced into the 1960s and serving in US forces officially into the 1980s. By the end of WW2, the USSR had fielded the largest number of submachine guns, with whole infantry battalions being armed with little else. Even in the hands of conscripted soldiers just out of basic training, the volume of fire produced by massed SMGs could be overwhelming. After WW2, the submachine gun's popularity in the military continued but began a slow decline, primarily being replaced by assault rifles, which filled a niche between the SMG and the battle rifle. However, they continued to be used significantly by police and special operations forces.

Modern

special operations Following World War II, the role of submachine guns was greatly diminished with the introduction of modern compact assault rifles, such as the CAR-15 and Heckler & Koch HK 53. Submachine guns are still used by special forces, air crews, armored vehicle crews, counter-terrorist units, and Naval personnel. Submachine guns lend themselves to moderation with suppressors, particularly so in cases where the weapon is loaded with subsonic ammunition. The Sten and modern-day Heckler & Koch MP5 have all been manufactured with quiet, integral silencers, and such weapons are favourites of special forces and police units. Prominent recent examples of the submachine gun are the Israeli Military Industries Uzi submachine gun, the Heckler & Koch MP5 series, the Ingram MAC-10, the Skorpion, the Sterling and the FN P90 (itself part of a new generation of 'personal defence weapons', firing cartridges intermediate in power between a pistol and assault rifle round). A small number of pistols have been available in fully-automatic or burst-fire variants, such as the Glock 18, the Stechkin, the Beretta 93R and the Heckler & Koch VP70.

Legality

In the United States, submachine guns have been categorized as NFA weapons (also known as Title II weapons), so being because they are regulated under the National Firearms Act of 1934 and as amended by Title II of the Gun Control Act of 1968. NFA firearms can be legally owned only if state and local law permit it, all the proper paperwork is submitted and approved, and a one time tax of $200 is paid. Certain submachine guns have also been available in specially-modified semi-automatic form, with non-removable 16 inch (406 mm) barrels and receivers modified so as to prevent conversion into a fully-automatic firearm; in this case, the submachine guns are treated as rifles, and are not subject to further regulations beyond those required for ownership of a rifle. In Europe, Switzerland allows the private ownership of semi-automatic submachine guns as sporting firearms. Fully automatic submachine guns may only be owned by collectors and may not be fired in fully automatic mode. Compare machine pistol, carbine.

Famous submachine guns

carbine
- Thompson submachine gun .45
- MP38 9 mm; MP40 9 mm
- M3 SMG aka Grease Gun .45
- Sten gun 9 mm
- IMI Uzi 9 mm
- HK: MP5 9 mm (also 10 mm and .40 S&W); MP7 4.6 mm
- Beretta PM12 9 mm
- FN P90 5.7 mm
- Glauberyt 9 mm
- Owen Gun 9 mm
- Skorpion
- MAC-10
- PPSh-41

Selective fire

A selective fire weapon can be fired in either of at least two modes, usually depending on the position of a selector switch. Selective fire weapons almost always have a semi-automatic mode, where the weapon automatically reloads the chamber after each round is fired, but requires that the trigger be pulled again before firing the next round. This allows for rapid and (in theory) aimed fire. In some cases the selection is between different rates of automatic fire. The selection is often by a small rotating switch, but there have been other ways of choosing the mode of fire. Some selective fire weapons offer a burst mode as the second option, where each pull of the trigger automatically fires a predetermined number of rounds, but won't fire any more until the trigger is pulled again. The current U.S. standard assault rifle, the M16A2, fires three rounds with each pull of the trigger when it is in burst mode. A common version of the Heckler & Koch MP5 submachine gun (widely used by SWAT teams and Special Operations military personnel) has the capability to fire two to four round bursts, or to be fired as fully-automatic. The majority of selective fire weapons have a fully-automatic mode as the second option. With each pull of the trigger, the weapon continues to load and fire rounds until the trigger is released or the ammunition is depleted. The M14A1 and M16A1 of Vietnam fame; the ubiquitous Soviet-designed AK47; the Israeli Galil; some variants of the FN FAL; the Chinese QBZ-95; the German G3 rifle; and the M4A1 carbine are but a few examples of this type of selective fire weapon.

Assault rifle

). This version was adopted in 1982]] An assault rifle is a type of automatic rifle. They have been defined various ways, but they are generally understood to be selective fire rifles or carbines (depending on the particular firearm's size), using intermediate-powered ammunition. They can be considered a compromise between the more powerful light machineguns and the weaker submachine gun. Assault rifles are the standard small arm in most modern armies. The name is a literal translation of the German term Sturmgewehr, first applied to the Sturmgewehr 44 developed during WW2, and gradually became a popular term for this type of firearm. The term has since been retro-actively applied to earlier weapons with similar traits.

History

1900s to the 1930s: light automatic rifles using rifle cartridges

WW2 These automatic firearms used pre-existing rifle cartridges, kinetic energy ranged between 3000-5000 J, velocites of 750 to 900 m/s and bullets of 9 to 13 g. The first true assault rifle was probably the Italian-made Cei-Rigotti, which was developed around the beginning of the 20th century but never entered military service. The first service assault rifle was the Russian Federov Avtomat of 1916 chambered for the Japanese Arisaka 6.5×50 mm rifle cartridge, which due to supply problems was only used in small numbers. The Browning Automatic Rifle was a World War I era weapon that used a full power round. It was an automatic rifle by today's definition, and designed for single accurate shots and suppressive automatic fire. The weight of roughly 15 pounds (7 kg) meant that it was rather cumbersome for closer quarters. Later developments added heavier barrels and bipods that lent it to being used as more like today's light machine gun or squad automatic weapon though it did help establish the doctrine of use for light select fire rifles. The BAR was produced in large numbers, widely adopted, and served into the 1960s with the US military and other nations. While it did not use an intermediate cartridge, it was an intermediate weapon between the newly adopted submachine guns and heavier machine guns like the Lewis Gun.

1930s:automatic intermediate weapons

These automatic and semi-automatic firearms used new intermediate cartridges based on enhancing pistol ammunition or greatly reducing standard rifle ammunition Lewis Gun An attempt to provide soldiers with a rifle with an intermediate-power ammunition and heavier than submachine guns (too weak and with too short a range due to the pistol ammunition), but lighter than long rifles (uncomfortable to shoot, and difficult to control on full-automatic because of the powerful ammunition and more expensive to design and manufacture), by the Italian arms company Beretta resulted with its MAB 38 (Moschetto Automatico Beretta 1938). The MAB 38 used a Fiocchi 9M38 cartridge, a higher-powered 9 mm Parabellum, which could provide a longer range. The useful range was about 200 m, although it was declared at 500 m. The MAB 38 was a multipurpose weapon. In 1938, prior to World War 2, the U.S. introduced the M1 Carbine which was an intermediate power weapon. It was originally going to have automatic fire but this was dropped for the first version, though later in the war select fire variants were made (M2 and M3 Carbines). The M1 Carbine series had higher hitting power than submachine guns, but less than full size automatic rifles such as the BAR. The .30 Carbine ammunition has since been used with other weapons including submachine guns and pistols. The 18 inch barrel of the M1 gave the bullet a higher muzzle velocity than shorter barreled weapons that use it. The M1 Carbine series was designed for close-in engagements, a concept that would be re-applied again and again, but the M1 marked the first time that such an intermediate weapon would be mass produced in such large numbers. The M1 carbine series became the most produced US weapon of the war, with millions made. The M1 Carbine series would serve until replaced in the 1960s by the M16 rifle in the US military, but it continued to serve in some others.

1940s and 1950s: Maschinenkarabiner, Sturmgewehr, & the AK-47

These automatic firearms used new higher power intermediate cartridges with pointed bullets, using standard rifle calibers with reduced propellent loads and slightly lighter bullets. Kinetic energy ranged between 1400-2100J, velocities of 600-800m/s and bullets of 7-9g .30 Carbine Germany, like other countries, had studied the problem since World War I, and their factories made a variety of non-standard cartridges, so they had less incentive to remain with their existing calibers. At first they were still using the 8×57JS and 8mm Mauser. The 7.92×30 mm cartridge was the best of that production, and in 1941 it was improved to 7.92×33 mm Infanterie Kurz Patrone. In 1942 it was improved again as Maschinenkarabiner Patrone S and in 1943 Pistolen Patrone 43mE, then finally Infanterie Kurz Patrone 43. All these names follow the troubled creation of the Sturmgewehr 44. In 1942 Walther presented the Maschinenkarabiner (automatic carbine, abbr. MK), named MKb42(W). In the same year, Haenel presented the MKb42(H), designed by Hugo Schmeisser as a result of this program. Rheinmetall-Borsig (some said Krieghoff) presented its FG-42 (Fallschirmjaeger Gewehr 42) though this was in a different role, and using a heavy 8 x 57 mm cartridge (This weapon did not use an intermediate cartridge). The FG-42 was sponsored by Hermann Göring. War-time tests in Russia indicated the MKb42(H) was the best of the three. Schmeisser developed it first as the MP43, then MP43/1 and finally as the Stg 44. It immediately entered large scale production. More than 5,000 pieces had been produced by February 1944, 55,000 by the following November. The Soviet Union developed the AK-47, which was mechanically different but had a roughly similar paradigm. The round it fired was a 7.62×39 mm which had been developed during WW2 for a different weapon, but it was used in the AK as well. The round was similar to the Stg's bullet in that the bullet was of the same caliber as rifle ammunition, but with a slightly lighter bullet, less propellant and also with a pointed rather than rounded tip as in pistol ammunition. Pointed tips were a common feature on full power rifle rounds, since they were first adopted by the French in the late 1800s for their rifle. At the time of the standardization of NATO on the full size 7.62 mm cartridge, there had been dissenting voices calling for an intermediate size cartridge and the British had developed and put into limited service the EM2 bullpup design with a .280 inch round. The larger round carried the day and the EM2 was retired.

1960s and 1970s: lighter automatic weapons and lighter smaller bullets

These automatic firearms used intermediate cartridges with much lighter bullets and smaller calibers, but fired at very high velocity, kinetic energy ranged between 1300-1800J, velocities of 900-1050m/s, and bullets of 3-4g bullpup).The SIG fires Gw Pat.90, which has the same caliber as 5.56 mm NATO.]] Many nations continued the development of traditional high-powered rifles with ranges of 500 meters and beyond. Most designs of this period used low-caliber but high-velocity ammunition, with some experiments in flechettes and other exotic ammunition. Statistical studies of World War II battles performed by the U.S. Army revealed that infantry combat beyond 300 meters (325 yards) was rare. The Russians saw no reason to make a rifle that shot beyond a rifleman's ability to aim. Therefore a lighter, less-powerful cartridge could be effective. This permitted a lighter rifle and enabled troops to carry more ammunition, making them more autonomous. A greater amount of the lighter ammunition could be transported in the same amount of space. In addition, the smaller size and handiness of an assault rifle would benefit tank crews, support troops, and units with missions other than front-line combat. The 5.56 mm NATO cartridge was developed in the 1960s, and was adopted for use in the M16 assault rifle. The M16A1 version soon followed, then was replaced in 1982 by the M16A2. The Soviet Union also developed its own similar round, the 5.45×39mm, which was used in the AK-74, the successor of the AK-47. These rounds are usually considered less lethal then the previous generation of assault rifle rounds that fired larger rifle caliber ammunition with reduced propellant, but the smaller caliber and lighter bullets achieve higher velocities then even a hunting rifle bullet. These high speeds induce additional lethality through bullet shattering or expanding (the bullet is designed to expand or shatter when it hits the target), although these high speed rounds generally do not exceed the momentum of the heavier (but slower) bullets of the less sophisticated AK-47. Additionally, these newer rounds have the ability to tumble into the body much more quickly than heavy rounds causing serious wounds from a much smaller projectile.

1970s, 1980s, 1990s: new form factors and features

These automatic firearms usually used the same rounds, but used new form factors, materials, and added things like standard scopes AK-47). It was adopted in 1978]] The biggest change since adoption of high velocity rounds of 5 mm caliber and higher, has been designs that have new form factors, sights, electronics, and materials. A number of bullpup rifles, entered service in the late 1970s, 1980s and 1990s. Although bullpup rifles had existed since the 1930s, Britain's EM2 was one of the few bullpup assault rifles prior to this time. Examples of the new trend include the FAMAS, Steyr AUG, and SA80. They were all bullpup rifles that made heavy use of composites and plastics with ambidextrous controls, and the latter both added a low power optical scope to the standard service version. The SAR-21, the Tavor TAR-21, and QBZ-95 follow a similar trend as well, with a bullpup configuration and heavy use of composites. The G36, adopted in the late 1990s by Spain and Germany was of the traditional configuration but also had integral scope and composite exterior. The XM8, developed from the G36 had similar features, but also added more electronics such as laser sight, round counter, and integral infrared laser and pointers. The trend in the new designs, and very likely future ones, is towards more integrated features and lighter weight with new materials and configurations. Introduction of a new ammunition would require retooling factories, phasing out conventional ammunition and in general infrastructure change that is considered by many military planners too expensive to undertake. Some have called for a reintroduction of larger caliber rounds to improve conventional lethality, or an increase in caliber in the 6-7 mm range, with rifle round velocities and lower mass bullets: a kind of intermediate philosophy between the smaller caliber-faster modern rounds and the standard caliber-slower rounds of the previous generation. China in the late 1980's introduced a 5.8×42mm round, with a initial velocity of 930m/s, 4.26g bullet and 1842j of energy, China claims the new round provides superior performace and lethality to the NATO and modern Soviet intermediate rounds. Development of a 4.73mm caseless ammunition and advanced assault rifle in the 1970-1980's by Germany was effectively halted by the German reunification in 1990, and that rifle never entered full production.

"Assault weapons"

Primarily in the United States, the term assault weapon is an arbitrary phrase used to describe a collection of semi-automatic firearms that have certain features, such as a folding stock or the ability to accept a detachable magazine of a capacity larger than ten rounds. It has been used primarily in relation to a specific expired gun law that was commonly known as the 'Assault Weapons Ban', 'Clinton gun ban', or '1994 crime bill'. It is a common misconception that this law restricted or banned weapons capable of fully automatic fire, such as assault rifles and machine guns. However, assault weapons are by legal definition not fully automatic weapons, and vice versa, and thus fully automatic weapons were unaffected by the ban, although they have been heavily restricted since the National Firearms Act of 1934. The term 'assault weapon' was previously (before the bill), and still is sometimes used to refer to fully automatic weapon; but no longer in any legal sense after the bill at the national level. Many states and localities still use the term assault weapon with a variety of variations following the California model loosely. See separate article on assault weapons for further information.

External links

- [http://www.quarry.nildram.co.uk/Assault.htm Assault Rifles and their Ammunition: History and Prospects] Category:Rifles
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