Small Arms

Handgun

The smallest of all small arms is the handgun, which is perhaps more commonly called a "pistol". There are three common types of handguns: single-shot pistols (more common historically), revolvers, and semi-automatic pistols. Revolvers have a number of firing chambers in a revolving cylinder; each chamber in the cylinder is loaded with a single cartridge. Semi-automatic pistols have a single fixed firing chamber and a removable magazine so they can be used to fire several shots. The Italian-made Mateba revolver is a rare "hybrid," a semi-automatic revolver. Each press of the trigger fires a cartridge and rotates the cylinder so that the next cartridge may be fired immediately.

Handguns differ from rifles and shotguns in that they do not have shoulder stock and are designed to be fired with one or two hands. While the term 'pistol' defines any handheld firearm, it is common to refer to a single-shot or auto-loading handgun as a 'pistol' and a revolver as a 'revolver'.

The term 'automatic pistol' is sometimes used and is somewhat misleading in that the term 'automatic' does not refer to the firing mechanism, but rather the reloading mechanism. When fired, an automatic pistol uses recoil and/or propellent gases to automatically extract the spent cartridge and insert a fresh one from a magazine. Usually (but not always) the firing mechanism is automatically cocked as well. An automatic pistol fires one shot per trigger pull, unlike an automatic weapon such as a machine gun, which fires as long as the trigger is held down. There are, however, some fully-automatic handguns (often referred to as machine pistols) so, to avoid such ambiguity and confusion, the term semi-automatic (or semiautomatic) is preferred when referring to a weapon that fires only one shot per trigger pull.

Prior to the 19th century, all handguns were single-shot muzzleloaders. With the invention of the revolver in 1818, handguns capable of holding multiple rounds became popular. At the end of the 20th century, most handguns are semi-automatic, although revolvers are still widely used. Generally speaking, military and police forces use automatic pistols due to their high magazine capacities (10, 15, 17 or, in some cases, up to 25+ rounds of ammunition) and ability to rapidly reload by simply removing the empty magazine and inserting a new one. Handgun hunters use revolvers almost exclusivly due to the fact that hunting cartridges are generally much more powerful than autopistol cartridges and the simplicity and durability of the revolver design is well-suited to them. Lawfully armed citizens carry either type, depending on personal preference.

Handguns come in many shapes and sizes. For example, the "derringer" (a generic term based on the mid-19th-century "Deringer" brand name) is a very small, short-barreled handgun, usually with one or two barrels but sometimes more (some 19th-century derringers had four barrels) that have to be manually reloaded after being fired. Carefully matched single-shot duelling pistols were used primarily in the 18th and 19th centuries to settle serious differences among "gentlemen": Alexander Hamilton and Aaron Burr are probably the most prominent Americans who used duelling pistols to settle their differences. Fully automatic, relatively easily concealed machine pistols, such as the MAC-10, GLOCK 18, and the Beretta 93R, were a late 20th-century development.

Handguns are small and usually made to be easily concealed, thus making them a very common choice for personal protection. In the military, handguns are usually issued to those who are not expected to need more potent (and more expensive) weapons, such as general and staff officers, and to those for whom there is no room for a full-sized rifle, such as armored vehicle and air crews. In this last role, they often compete with the carbine, which is also usually issued to airborne infantry because of its small size. Outside the military, handguns are the usual armament for police (in those jurisdictions where police are armed) and, where legal, for private citizens. Private citizens in most jurisdictions usually carry only concealed handguns in public except when hunting, since an unconcealed weapon would attract undue attention, and would therefore be less secure, athough there are significant numbers of states in the US that continue to permit open carry of handguns. In the United States, the number of states which permit concealed carry has recently grown to over 35, and several states have well over 200,000 permit holders. Despite Second Amendment constitutional roots in the United States, the concept of citizens carrying a concealed weapon for self-defense is often a contentious political issue.

Handguns are also used for many sporting purposes and hunting, although hunting usage is usually viewed as somewhat atypical due to the limited range and accuracy of handguns. Some hunters however do their hunting in areas of dense cover where long guns would be awkward or relish the increased challenge involved in handgun hunting due to the necessity of approaching the game animal more closely. Small-bore (e.g., .22 caliber rimfire) handguns have long been very popular for competitive target shooting, partially due to the low cost of both the weapons and the ammunition, and there is also a rapidly growing number of sporting competitions for larger calibers.

Long guns

Most modern long guns are either rifles or shotguns. Historically, a long smoothbore firearm was known as a musket. A rifle has a rifled barrel that fires single bullets, while a shotgun fires packets of shot, a single slug, a sabot, or a speciality round (tear gas, Bolo Shell, lead powder, etc.). Rifles are often built for accuracy and long range and are aimed, while shotguns are usually designed to quickly hit a moving target and are instead "pointed". Rifles have a very small impact area but a long range and high accuracy. Shotguns have a large impact area with considerably less range and accuracy. However, the larger impact area can compensate for reduced accuracy, since shot spreads during flight; consequently, in hunting, shotguns are used for flying game.

Rifles and shotguns are commonly used for hunting and often to defend a home or place of business. Usually, large game are hunted with rifles (although shotguns can be used—deer hunting with a shotgun is possible with the use of buckshot, sabots or slugs) while birds are hunted with shotguns. Shotguns are sometimes preferred for defending a home or business due to their wide impact area, multiple wound tracks (when using buckshot), shorter range, and reduced penetration of walls, which significantly reduces the likelihood of unintended harm, although the handgun is also commonly preferred.

There are a variety of types of rifles and shotguns based on the method they are reloaded. Bolt-action and lever-action rifles are manually manipulated. Manual manipulation of the bolt or the lever causes the spent cartridge to be removed, the firing mechanism recocked, and a fresh cartridge inserted. These two types of action are almost exclusively used by rifles.

Slide-action (commonly called 'pump-action') rifles and shotguns are manually cycled by shuttling the foregrip of the firearm back and forth. This type of action is typically used by shotguns, but several major manufacturers make rifles as well.

Automatic and semi-automatic rifles and shotguns both use either recoil or propellent gases to operate the firing mechanism that extracts and loads cartridges and recocks the firing mechanism. Semi-automatics employ an interrupter mechanism to only fire one shot per pull of the trigger, while full-automatics do not have such a system and fire multiple shots with a single pull of the trigger.

Both rifles and shotguns also come in break-action varieties that do not have any kind of reloading mechanism at all but must be hand-loaded after each shot. Both rifles and shotguns come in single- and double-barreled varieties; however due to the expense and difficulty of manufacturing double-barreled rifles are rare. Double-barreled rifles are typically intended for African big-game hunts where the animals are dangerous, ranges are short, and speed is of the essence. Very large and powerful calibers are normal for these types of guns.

Rifles have been in nationally featured marksmanship events in Europe and the United States since at least the 18th century, when rifles were first becoming widely available—one of the earliest purely "American" rifle-shooting competitions took place in 1775, when Daniel Morgan was recruiting sharpshooters in Virginia for the impending war with Great Britain. In some countries, rifle marksmanship is still a matter of national pride. Some specialized rifles in the larger calibers are claimed to have an accurate range of up to about one mile (1600 m), although most have considerably less effective range. In the second half of the 20th century, competitive shotgun sports became perhaps even more popular than riflery, largely due to the motion and immediate feedback in activities such as skeet, trap and sporting clays.

Machine guns

A machine gun is a fully automatic firearm used almost exclusively by the military. Although not widely fielded until World War I, early machine guns were being used by the military in the late 19th century (e.g., the Gatling gun). They are primarily defensive weapons, mainly because of the difficulties involved in moving and placing them, and their inherent lack of accuracy. In contrast, light machine guns (such as the U.S. military's M249 Squad Automatic Weapon (SAW) and the M60 machine gun, both of which are small-caliber weapons) are often wielded by a single infantryman; they provide a high rate of fire typically used as either suppressing fire or covering fire during infantry movement. Machine guns are also often mounted on vehicles or helicopters, and have often been used since World War II as offensive weapons in fighter aircraft and tanks (e.g., for air combat or suppressing fire for ground troop support).

A submachine gun is a machine gun that fires cartridges that would otherwise be used in a handgun. Probably the most well-known example of a submachine gun is the Thompson submachine gun (the "Tommy Gun" of gangster movies), which fires .45 ACP cartridges. Other well-known examples are the Israeli Uzi, the British Sten, and the German MP5, all of which implement the 9 mm Luger Parabellum, and the U.S.'s M3 Grease Gun which fires .45 ACP.

In United States law, a Machine Gun is defined (in part) by The National Firearms Act of 1934, United States code Title 26, Subtitle E, Chapter 53, Subchapter B, Part 1, § 5845 as:

"... any weapon which shoots ... automatically more than one shot, without manual reloading, by a single function of the trigger."

In the United States, purchases of machine guns manufactured after 1986 by civilians were banned by the Firearm Owners Protection Act (FOPA), passed in that year. Importation of machine guns for civilian sale in the U.S. was banned by the Gun Control Act of 1968. Machine guns manufactured prior to 1986 or imported prior to 1968 can still be legally transferred to civilians who pay a substantial tax to the BATFE and pass a background investigation. In addition, "transferable" machine guns must have been registered with the BATFE prior to 1986. Machine Gun parts kits (which do not include a functional receiver) can be transferred without restriction. Permission must be received from BATFE to move a machine gun between states.

One of the most popular, most produced and most used machine guns in the world is the Soviet AK-47. It served in the Soviet army as standard infantry weapon issue, as well as in many other east-block states, and is still used as standard military equipment in some former Warsaw Pact countries. As over 100 million AK-47s were manufactured, it has also become the weapon of choice worldwide for many criminal or terrorist organizations . A semi-automatic version of this firearm is available in many locales where fully-automatic weaponry is not available.