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.
A rifle is a long-barreled firearm designed for accurate shooting and higher stopping power, with a barrel that has a helical pattern of grooves (rifling) cut into the bore wall. In keeping with their focus on accuracy, rifles are typically designed to be held with both hands and braced firmly against the shooter's shoulder via a buttstock for stability during shooting. Rifles are used extensively in warfare, law enforcement, hunting and target shooting sports.
A shotgun is a long-barreled firearm designed to shoot a straight-walled cartridge known as a shotshell, which discharges numerous small spherical projectiles called shot, or a single solid projectile called a slug. Shotguns are most commonly used as smoothbore firearms, meaning that their gun barrels have no rifling on the inner wall, but rifled barrels for shooting sabot slugs are also available.
In firearm designs, the term single-shot refers to guns that can hold only a single round of ammunition inside and thus must be reloaded manually after every shot. Compared to multi-shot repeating firearms ("repeaters"), single-shot designs have no moving parts other than the trigger, hammer/firing pin or frizzen, and therefore do not need a sizable receiver behind the barrel to accommodate a moving action, making them far less complex and more robust than revolvers or magazine/belt-fed firearms, but also with much slower rates of fire.
A muzzleloader is any firearm in which the user loads the projectile and the propellant charge into the muzzle end of the gun. This is distinct from the modern designs of breech-loading firearms, in which user loads the ammunition into the breech end of the barrel. The term "muzzleloader" applies to both rifled and smoothbore type muzzleloaders, and may also refer to the marksman who specializes in the shooting of such firearms. The firing methods, paraphernalia and mechanism further divide both categories as do caliber.
Flintlock is a general term for any firearm that uses a flint-striking ignition mechanism, the first of which appeared in Western Europe in the early 16th century. The term may also apply to a particular form of the mechanism itself, also known as the true flintlock, that was introduced in the early 17th century, and gradually replaced earlier firearm-ignition technologies, such as the matchlock, the wheellock, and the earlier flintlock mechanisms such as the snaplock and snaphaunce.
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 (11.43mm). 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.
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 more portable when maneuvering in confined spaces and for that reason law enforcement and military personnel find it useful in close-quarters combat scenarios. As a result of the shorter barrel length, any shotgun with a tubular magazine will have a reduction in its magazine capacity.
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.
The Mossberg 500 (M500) is a series of pump action shotguns manufactured by O.F. Mossberg & Sons. The 500 series comprises widely varying models of hammerless repeaters, all of which share the same basic receiver and action, but differ in bore size, barrel length, choke options, magazine capacity, stock and forearm materials. Model numbers included in the 500 series are the 500, 505, 510, 535, and 590. The Revelation 310 and the New Haven 600 were also variations of the 500 series produced by Mossberg under different names. By 2021, 11,000,000 M500s had been produced, making it the most-produced shotgun of all time.
A combat shotgun is a shotgun issued by militaries for warfare. The earliest shotguns specifically designed for combat were the trench guns or trench shotguns issued in World War I. While limited in range, the multiple projectiles typically used in a shotgun shell provide increased hit probability unmatched by other small arms.
A shotgun shell, shotshell, or shell is a type of rimmed, cylindrical (straight-walled) cartridges used specifically in shotguns, and is typically loaded with numerous small, pellet-like spherical sub-projectiles called shot, fired through a smoothbore barrel with a tapered constriction at the muzzle to regulate the extent of scattering. A shell can sometimes also contain only a single large solid projectile known as a slug. The hull usually consists of a paper or plastic tube often covered at the base by a metallic head cover which retains a primer, and the shot charge is typically contained by a wadding/sabot inside the case. The caliber of the shotshell is known as its gauge.
The .410 bore (10.4 mm) is one of the smallest caliber of shotgun shell commonly available. A .410 bore shotgun loaded with shot shells is well suited for small game hunting and pest control. The .410 started off in the United Kingdom as a garden gun along with the .360 and the No. 3 bore (9 mm) rimfire, No. 2 bore (7 mm) rimfire, and No. 1 bore (6 mm) rimfire. .410 shells have similar base dimensions to the .45 Colt cartridge, allowing many single-shot firearms, as well as derringers and revolvers chambered in that caliber, to fire .410 shot shells without any modifications.
A riot shotgun is a shotgun designed or modified for use as a primarily defensive weapon, by the use of a short barrel and sometimes a larger magazine capacity than shotguns marketed for hunting. The riot shotgun is used by military personnel for guard duty and was at one time used for riot control, and is commonly used as a door breaching and patrol weapon by law enforcement personnel, as well as a home defense weapon by civilians. Guns of this type are often labeled as breaching shotguns, tactical shotguns or special-purpose shotguns to denote the larger scope of their use; however, these are largely marketing terms.
A shotgun slug is a heavy projectile made of lead, copper, or other material and fired from a shotgun. Slugs are designed for hunting large game, and other uses, particularly in areas near human population where their short range and slow speed helps increase safety margin. The first effective modern shotgun slug was introduced by Wilhelm Brenneke in 1898, and his design remains in use today. Most shotgun slugs are designed to be fired through a cylinder bore, improved cylinder choke, rifled choke tubes, or fully rifled bores. Slugs differ from round ball lead projectiles in that they are stabilized in some manner.
A rifled musket, rifle musket, or rifle-musket is a type of firearm made in the mid-19th century. Originally the term referred only to muskets that had been produced as a smoothbore weapon and later had their barrels replaced with rifled barrels. The term later included rifles that directly replaced, and were of the same design overall as, a particular model of smoothbore musket.
The gauge of a firearm is a unit of measurement used to express the inner diameter of the barrel.
The musketoon is a shorter-barrelled version of the musket and served in the roles of a shotgun or carbine. Musketoons could be of the same caliber as the issue musket or of a much larger caliber, 1.0–2.5 inches (25–63 mm). The musketoon is most commonly associated with naval use, and pirates in particular, though they also served in a carbine role with cavalry. Musketoon barrels were often flared at the muzzle, resembling a cannon or blunderbuss.
The following are terms related to firearms and ammunition topics.
A dragon is a shortened version of blunderbuss, a firearm with a short, large caliber barrel which is flared at the muzzle and frequently throughout the entire bore. Dragons were typically issued to dragoon cavalry, who needed a lightweight, easily handled firearm to use while mounted.
