Medium machine gun

A medium machine gun or MMG, in modern terms, usually refers to a belt-fed automatic firearm firing a full-power rifle cartridge and typically weighs from 15 to 40 pounds (6.8 to 18.1 kg). MMGs usually have some type of provision for extended firing, such as a removable or extra-heavy barrel, cooling fins, or a water cooling jacket, but are light enough to be used with a bipod. They occupy a gray area between light machine guns and heavy machine guns.

Two features which have remained somewhat constant, however, are some added ability for greater fire over automatic rifles, and the ability to be used in both light infantry support roles on a bipod, but also on mounts and tripods. While heavy machine guns (HMG) are mostly fired from heavy mounts, and light machine guns (LMG) are usually operated with bipods, MMGs have historically been used in both. Heavy machine guns are either crew-served or mounted, while MMGs are usually operated by one to two soldiers. Light machine guns and automatic rifles are often an individual weapon with a fixed, naked barrel. On the other hand medium machine guns have usually had more endurance of some sort, such as the aforementioned heavier barrel, barrel-change, fins etc.

Squad automatic weapon

A squad automatic weapon (SAW, also known as section automatic weapon or light support weapon) is a light or general purpose machine gun, usually equipped with a bipod and firing a rifle-caliber cartridge. A SAW is used to provide suppressive fire for an infantry squad or section, and typically uses the same ammunition as the assault rifles carried by other members of the unit, simplifying military logistics.

The basic use of this weapon is to force enemy troops to take cover and reduce the effectiveness of their return fire while friendly troops advance, increasing the likelihood of a successful attack against an enemy position. SAWs must therefore be light enough for an individual soldier to carry and fire. SAWs may also be used in defending friendly positions, but cannot provide a field of fire as effective as that of a tripod-mounted machine gun.

Many SAWs (such as the RPK-74 and L86) are modified assault rifles. The most common SAWs in use today are derived from two basic patterns: RPK or FN Minimi. One of the first weapons designed for this role was the M1918 Browning Automatic Rifle, which, though having a limited magazine capacity, was still higher than the typical infantry rifle, and it gave the infantry a base of fire weapon that was more suited to maneuver warfare than the bulkier machine guns of the period, such as the M1919 Browning machine gun.

Minigun

The minigun is a multi-barrel machine gun with a high rate of fire (several thousand rounds per minute), employing Gatling-style rotating barrels and an external power source. In popular culture, the term "minigun" has come to refer to any externally-powered Gatling gun of rifle caliber, though the term is sometimes used to refer to guns of similar rates of fire and configuration, regardless of power source and caliber. Specifically, minigun refers to a single weapon, originally produced by General Electric. The "mini" of the name is in comparison to designs that use a similar firing mechanism but 20 mm or larger shells, such as General Electric's earlier M61 Vulcan.

• Design and variants

The basic weapon is a 6-barrel, air-cooled, and electrically driven machine gun. The electric drive rotates the weapon within its housing, with a rotating firing pin assembly and rotary chamber. The minigun's multibarrel design helps prevent overheating, but also serves other functions. Multiple barrels allow for a greater capacity for a high firing rate, since the serial process of firing/extraction/loading is taking place in all barrels simultaneously. Thus, as one barrel fires, two others are in different stages of shell extraction and another three are being loaded. The minigun is composed of multiple closed-bolt rifle barrels arranged in a circular housing. The barrels are rotated by an external power source: usually electric, pneumatic, or hydraulic. Other rotating-barrel cannons are powered by the gas pressure or recoil energy of fired cartridges. A gas-operated variant, designated the XM133, was also developed, but was not put into production.

While the weapon can feed from linked ammunition, it requires a delinking feeder to strip the links as the rounds are introduced to the chambers. The original unit was designated MAU-56/A, but has since been replaced by an improved MAU-201/A unit.

G.E.'s minigun is in use in all major branches of the US military, under a number of designations. The basic fixed armament version was given the designation M134 by the U.S. Army, while the exact same weapon was designated GAU-2/A by the U.S. Air Force. The USAF weapon has three subvariants, while the US Army weapon appears to have incorporated any new improvements without a change in designation. Available sources show a relation between both M134 and GAU-2/A and M134 and GAU-2B/A. A separate variant, designated XM196, with an added ejection sprocket was developed specifically for the XM53 Armament Subsystem on the AH-56 Cheyenne helicopter.

Another variant was developed by the U.S. Air Force specifically for flexible installations, at the time primarily for the UH-1N helicopter, as the GAU-17/A. The primary end users of the GAU-17/A have been the U.S. Navy and the U.S. Marine Corps, who mount them on as defensive armament on a number of helicopters and surface ships. The weapon is part of both the A/A49E-11 armament system on the UH-1N and A/A49E-13 armament subsystem on the HH-60H aircraft. The weapons on these systems feature a selectable fire rate of either 2,000 or 4,000 rpm. There is mention of a possible GAUSE-17 designation (GAU-Shipboard Equipment-17), in reference to the system when mounted on surface ships, though this would not follow the official ASETDS designation system's format.

Other manufacturers in the United States also produce Miniguns with various refinements of their own, including Dillon Aerospace (the "M134D"), and Garwood Industries (the "M134G").

Military and civilian handguns

• Handgun
  • Captive bolt pistol
  • Hand cannon
  • Machine pistol
  • Pistol
    • Howdah pistol
    • Junk gun
    • Mousegun
    • Pocket pistol
  • Revolver

Handgun

designed to be held in the hand when used. This characteristic differentiates handguns as a general class of firearms from their larger counterparts: long guns such as rifles and shotguns, mounted weapons such as machine guns and autocannons, and larger weapons such as artillery.

Some handgun subtypes include single-shot pistols, revolvers, semi-automatic pistols, and fully automatic, or machine pistols.

The overlapping variations in meaning of the words "pistol" and "handgun" are discussed below.

• Nomenclature variations

Multiple senses of the word "pistol"

The word "pistol" is often synonymous with the word "handgun". Some handgun experts make a technical distinction that views pistols as a subset of handguns. In American usage, the term "pistol" refers to a handgun whose chamber is integral with the barrel, making pistols distinct from the other main type of handgun, the revolver, which has a revolving cylinder containing multiple chambers. However, Commonwealth usage makes no distinction at a technical level—"pistol" may refer to revolvers, semi-automatics, or muzzle-loading/cap-&-ball handguns. For example, the official designation of the Webley Mk VI was "Pistol, Revolver, Webley No. 1 Mk VI", and the designation "Pistol No. 2 Mk I" was used to refer to both the Enfield Revolver and the later Browning Hi-Power semi-automatic.

The first pistols were made as early as the 15th century, however the creator is unknown. By the 18th century, the term came to be used often to refer to handheld firearms. Practical revolver designs appeared in the 19th century, and it was in that century that the (sometimes-observed) technical differentiation in usage of the words "pistol" and "revolver" developed.

Etymology of "pistol"

Hand Cannon from the Chinese Yuan Dynasty (1271-1368).

The word "pistol" is derived from the French pistole (or pistolet), which has these possible origins:

• From the Czech pistole and this one from the Czech píšťala (flute or pipe, referring to the shape of a Hussite firearm), via Middle High German pischulle and Middle French pistole.
• From the city of Pistoia, Italy, where hand-held guns (designed to be fired from horseback) were first produced in the 1540s.
• That early pistols were carried by cavalry in holsters hung from the pommel (or pistallo in medieval French) of a horse's saddle.

Captive bolt pistol

A captive bolt pistol (also variously known as a cattle gun, stunbolt gun, bolt gun, or stunner) is a device used for stunning beasts prior to slaughter. Proper stunning is essential to prevent the pain and suffering of the beast during the bleeding (exsanguination) process (which is itself necessary to prevent meat spoilage) during butchering. The principle behind captive bolt stunning is a forceful strike on the forehead using a bolt to induce unconsciousness. The bolt may or may not destroy part of the brain.

The bolt is a heavy rod made of non-rusting alloys, such as stainless steel. It is held in position inside the barrel of the stunner by means of rubber washers. The bolt is usually not visible in a stunner in good condition. The bolt is actuated by a trigger pull and is propelled forward by compressed air or by the discharge of a blank round ignited by a firing pin. After striking a shallow but forceful blow on (or through) the forehead of the beast, spring tension causes the bolt to recoil back into the barrel.

• Variations

The captive bolt pistols are of three types: penetrating, non-penetrating, and free bolt.

In the penetrating type, the stunner uses a pointed bolt which is propelled by pressurized air or a blank cartridge. The bolt penetrates the skull of the beast, enters the cranium, and catastrophically damages the cerebrum and part of the cerebellum. Due to concussion, destruction of vital centres of brain and an increase in intracranial pressure, the beast loses consciousness. This method is currently the most effective and widely used type of stunning, since it physically destroys brain matter (increasing the probability of a successful stun), while also leaving the brain stem intact (thus ensuring the heart continues to beat, facilitating a successful bleed). One disadvantage of this method is that brain matter is allowed into the blood stream, possibly contaminating other tissue with bovine spongiform encephalopathy (B.S.E.).

The action of a non-penetrating stunner is similar, but the bolt is blunt with a mushroom-shaped tip. The bolt strikes the forehead with great force and immediately retracts. This concussion is responsible for the unconsciousness of the animal. This type of stunner is less reliable at causing immediate and permanent unconsciousness than penetrating types; however, it has undergone a resurgence of popularity due to concerns about mad cow disease. In the European Union, this captive bolt design is required for slaughter of animals that will be used for pharmaceutical manufacture.

The free bolt stunner is used for the emergency in-the-field euthanasia of large farm-beasts who cannot be restrained. It differs from a true captive bolt gun in that the projectile is not retractable; it is similar in operation to a powder-actuated nail gun or conventional firearm. Capable of firing only when pressed firmly against a surface (typically the beast's forehead), the device fires a small projectile through the beast's skull. The veterinarian can then either leave the beast to expire from the projectile wound, or administer lethal drugs.

Machine pistol

A machine pistol is a handgun-style, magazine-fed and self-loading firearm, capable of fully automatic or burst fire, and normally chambered for pistol cartridges. The term is a literal translation of Maschinenpistole, the German term for a submachine gun. While the dividing line between machine pistols and compact submachine guns is hard to draw, the term submachine gun usually refers to larger automatic firearms. Typically, a submachine gun's operating mechanism is scaled down from that of a full-sized machine gun, while a machine pistol is built up from a semi-automatic pistol design.

Machine pistols are used by tactical police units such as SWAT teams or hostage rescue teams inside buildings and other cramped spaces. Machine pistols are also used by government security service bodyguards for VIPs and heads of state who need a weapon that can be concealed under clothing. They are also occasionally issued to undercover operatives in anti-drug units such as the US Drug Enforcement Administration, who need a small, concealable weapon with a high rate of fire. In a military setting, machine pistols are issued as personal defense sidearms to paratroopers, artillery crews, helicopter crews or tank crews. They have also been used in close quarters combat (CQC) settings where a small weapon is needed (e.g. by special forces attacking buildings or tunnels).