A firearm is any type of gun that uses an explosive charge and is designed to be readily carried and used by an individual. The term is legally defined further in different countries.
In guns, particularly firearms, but not artillery, where a different definition may apply, caliber is the specified nominal internal diameter of the gun barrel bore – regardless of how or where the bore is measured and whether the finished bore matches that specification. It is measured in inches or in millimeters. In the United States it is expressed in hundredths of an inch; in the United Kingdom in thousandths; and elsewhere in millimeters. For example, a US "45 caliber" firearm has a barrel diameter of roughly 0.45 inches (11 mm). Barrel diameters can also be expressed using metric dimensions. For example, a "9 mm pistol" has a barrel diameter of about 9 millimeters. Since metric and US customary units do not convert evenly at this scale, metric conversions of caliber measured in decimal inches are typically approximations of the precise specifications in non-metric units, and vice versa.
Muzzle velocity is the speed of a projectile with respect to the muzzle at the moment it leaves the end of a gun's barrel. Firearm muzzle velocities range from approximately 120 m/s (390 ft/s) to 370 m/s (1,200 ft/s) in black powder muskets, to more than 1,200 m/s (3,900 ft/s) in modern rifles with high-velocity cartridges such as the .220 Swift and .204 Ruger, all the way to 1,700 m/s (5,600 ft/s) for tank guns firing kinetic energy penetrator ammunition. To simulate orbital debris impacts on spacecraft, NASA launches projectiles through light-gas guns at speeds up to 8,500 m/s (28,000 ft/s). FPS and MPH are the most common American measurements for bullets. Several factors, including the type of firearm, the cartridge, and the barrel length, determine the bullet's muzzle velocity.
The National Firearms Act (NFA), 73rd Congress, Sess. 2, ch. 757, 48 Stat. 1236 was enacted on June 26, 1934, and currently codified and amended as I.R.C. ch. 53. The law is an Act of Congress in the United States that, in general, imposes an excise tax on the manufacture and transfer of certain firearms and mandates the registration of those firearms. The NFA is also referred to as Title II of the federal firearms laws, with the Gun Control Act of 1968 ("GCA") as Title I.
A grenade launcher is a weapon that fires a specially designed, large-caliber projectile, often with an explosive, smoke, or gas warhead. Today, the term generally refers to a class of dedicated firearms firing unitary grenade cartridges. The most common type are man-portable, shoulder-fired weapons issued to individuals, although larger crew-served launchers are issued at higher levels of organization by military forces.
The M203 is a single-shot 40 mm under-barrel grenade launcher designed to attach to a rifle. It uses the same rounds as the older stand-alone M79 break-action grenade launcher, which utilizes the high-low propulsion system to keep recoil forces low. Quite versatile and compatible with many rifle models, the M203 was originally designed for the U.S. M16 and its carbine variant, the M4. The launcher can also be mounted onto a C7, a Canadian version of the M16 rifle; however, this requires the prior removal of the bottom handguard.
A sawed-off shotgun is a type of shotgun with a shorter gun barrel—typically under 18 inches (46 cm)—and often a pistol grip instead of a longer shoulder stock. Despite the colloquial term, barrels do not, strictly speaking, have to be shortened with a saw. Barrels can be manufactured at shorter lengths as an alternative to traditional, longer barrels. This makes them easier to transport and conceal due to their smaller profile and lighter weight. The design also makes the weapon easy to maneuver in cramped spaces, a feature sought by military close-quarters combat units and law enforcement SWAT team users. As a result of the shorter barrel length, any sawn-off shotgun with a magazine tube will have its capacity reduced.
A gun barrel is a crucial part of gun-type weapons such as small firearms, artillery pieces, and air guns. It is the straight shooting tube, usually made of rigid high-strength metal, through which a contained rapid expansion of high-pressure gas(es) is used to propel a projectile out of the front end (muzzle) at a high velocity. The hollow interior of the barrel is called the bore, and the diameter of the bore is called its caliber, usually measured in inches or millimetres.
A blank is a firearm cartridge that, when fired, does not shoot a projectile like a bullet or pellet, but generates a muzzle flash and an explosive sound like a normal gunshot would. Firearms may need to be modified to allow a blank to cycle the action, and the shooter experiences less recoil with a blank than with a live round. Blanks are often used in prop guns for shooting simulations that have no need for ballistic results, but still demand light and sound effects, such as in historical reenactments, special effects for theatre, movie and television productions, combat training, for signaling, and cowboy mounted shooting. Specialised blank cartridges are also used for their propellant force in fields as varied as construction, shooting sports, and fishing and general recreation.
In current usage, a riot gun or less-lethal launcher is a type of firearm used to fire "non-lethal" or "less-lethal" ammunition for the purpose of suppressing riots or apprehending suspects with minimal harm or risk. Less-lethal launchers may be special purpose firearms designed for riot control use, or standard firearms, usually shotguns and grenade launchers, adapted for riot control use with appropriate ammunition. The ammunition is most commonly found in 12 gauge shotguns and 37mm or 40 mm grenade launchers.
The Type 11 70 mm infantry mortar, was a muzzle-loading, rifled bore infantry mortar used by the Japanese. The Type 11 designation was given to this gun as it was accepted in the 11th year of Emperor Taishō's reign (1922). It was first used in 1922 and was the first mortar to be introduced by the Imperial Japanese Army. The Type 11 was later replaced by the Type 92 battalion gun.
37 mm flare or "1.5 inch" caliber is the specification for a common launching system for non-lethal and less-lethal ammunition. Such launchers are also often known as "gas guns" due to their original use by police for launching tear gas projectiles. 37 mm systems are typically smoothbore as rifling is unnecessary or even detrimental to the performance of the usual projectiles.
The Auto & Burglar Gun was a US-made factory-built handgun that was commercially manufactured by configuring a standard double-barrel shotgun with a pistol grip, at first engraving and later stamping "Auto & Burglar Gun" on each side of the frame, and shortening the barrels to about 10" to 12.2" in length. A holster with a flap and a snap was available for purchase from Ithaca. It was outsourced to a leather company and was embossed with "Auto & Burglar" on it. They are also very rare and are infrequently seen for sale in any condition.
A muzzle-loading rifle is a muzzle-loaded small arm or artillery piece that has a rifled barrel rather than a smoothbore. The term "rifled muzzle loader" typically is used to describe a type of artillery piece, although it is technically accurate for small arms as well. A shoulder arm is typically just called a "rifle", as almost all small arms were rifled by the time breechloading became prevalent. Muzzle and breechloading artillery served together for several decades, making a clear distinction more important. In the case of artillery, the abbreviation "RML" is often prefixed to the guns designation; a Rifled breech loader would be "RBL", or often just "BL", since smoothbore breechloading artillery is almost nonexistent. A muzzle loading weapon is loaded through the muzzle, or front of the barrel. This is the opposite of a breech-loading weapon or rifled breechloader (RBL), which is loaded from the breech-end of the barrel. The rifling grooves cut on the inside of the barrel cause the projectile to spin rapidly in flight, giving it greater stability and hence range and accuracy than smoothbore guns. Hand held rifles were well-developed by the 1740s. A popularly recognizable form of the "muzzleloader" is the Kentucky Rifle, which was actually developed in Pennsylvania. The American Longrifle evolved from the German "Jäger" rifle.
The legality of the potato-firing potato cannon varies among jurisdictions.
An antique firearm is a term used to describe a firearm that was designed and manufactured prior to the beginning of the 20th century. Although the exact definition of what constitutes an "antique firearm" varies between countries, the advent of smokeless powder or the start of the Boer War are often used as cut-off dates. Antique firearms are usually collected because of their historical interest and/or their monetary value.
The following are terms related to firearms and ammunition topics.
Title II weapons, or NFA firearms, are designations of certain weapons under the United States National Firearms Act (NFA).
The Marble Game Getter is a light, double-barrel (over-under), combination gun manufactured by the Marble's Arms & Manufacturing Company in Gladstone, Michigan. The firearm features a skeleton folding stock and a rifle barrel over a smooth-bore shotgun barrel. A manually pivoted hammer striker is used to select the upper or lower barrel. Three generations of the system were/are produced—First Generation, Second Generation and the Third Generation currently manufactured by Marble Arms.
A silencer, also known as a sound suppressor, suppressor, or sound moderator, is a muzzle device that suppresses the blast created when a gun is discharged, thereby reducing the acoustic intensity of the muzzle report and jump, by modulating the speed and pressure of the propellant gas released from the muzzle. Like other muzzle devices, a silencer can be a detachable accessory mounted to the muzzle, or an integral part of the barrel.
