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 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.
In firearms terminology, an action is the functional mechanism of a breech-loading firearm that handles the ammunition cartridges, or the method by which that mechanism works. Actions are technically not present on muzzleloaders, as all those are single-shot firearms with a closed off breech with the powder and projectile manually loaded from the muzzle. Instead, the muzzleloader ignition mechanism is referred to as the lock.
A derringer is a small handgun that is neither a revolver, semi-automatic pistol, nor machine pistol. It is not to be confused with mini-revolvers or pocket pistols, although some later derringers were manufactured with the pepperbox configuration. The modern derringer is often multi barreled, and is generally the smallest usable handgun of any given caliber and barrel length due to the lack of a moving action, which takes up more space behind the barrel. It is frequently used by women because it is easily concealable in a purse or a stocking.
The pepper-box revolver or simply pepperbox is a multiple-barrel firearm, mostly in the form of a handgun, that has three or more gun barrels in a revolving mechanism. Each barrel holds a single shot, and the shooter can manually rotate the whole barrel assembly to sequentially index each barrel into alignment with the lock or hammer, similar to rotation of a revolver's cylinder.
A lever action is a type of action for repeating firearms that uses a manually operated cocking handle located around the trigger guard area that pivots forward to move the bolt via internal linkages, which will feed and extract cartridges into and out of the chamber, and cock the firing pin mechanism. This contrasts to other type of repeating actions such as the bolt-action, pump-action, semi-automatic, fully automatic, and/or burst mode actions. A firearm using this operating mechanism is colloquially referred to as a levergun.
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 breechblock is the part of the firearm action that closes the breech of a breech loading weapon before or at the moment of firing. It seals the breech and contains the pressure generated by the ignited propellant. Retracting the breechblock allows the chamber to be loaded with a cartridge.
The lock of a firearm is the mechanism used to initiate firing. It is a historical term, in that it generally refers to such mechanisms used in muzzle-loading and early breech-loading firearms. Side-lock refers to the type of construction, in which the individual components of the mechanism are mounted either side of a single plate. The assembly is then mounted to the stock on the side of the firearm. In modern firearm designs, the mechanism to initiate firing is generally constructed within the frame or receiver of the firearm and is referred to as the firing or trigger mechanism.
The COP .357 is a 4-shot Derringer-type pistol chambered for .357 Magnum. The double-action weapon is about twice as wide, and substantially heavier than the typical .25 automatic pistol, though its relatively compact size and powerful cartridge made it an option for a defensive weapon or a police backup gun.
H&R 1871, LLC, or more commonly known as Harrington & Richardson, is an American brand of firearms and a subsidiary of JJE Capital Holdings. H&R ceased independent production February 27, 2015.
A hammerless firearm is a firearm that lacks an exposed hammer or hammer spur. Although it may not literally lack a hammer, it lacks an external hammer that the user can manipulate directly. One of the disadvantages of an exposed hammer spur is the tendency for it to get caught on items such as clothing; covering the hammer by removing the hammer spur reduces this from occurring.
Break action is a type of firearm action in which the barrel(s) are hinged much like a door and rotate perpendicularly to the bore axis to expose the breech and allow loading and unloading of cartridges. A separate operation may be required for the cocking of a hammer to fire the new round. There are many types of break-action firearms; break actions are universal in double-barreled shotguns, double-barreled rifles, combination guns, and are commonly found in single shot pistols, rifles, shotguns, including flare guns, grenade launchers, air guns, and some older revolver designs. They are also known as hinge-action, break-open, break-barrel, break-top, or, on old revolvers, top-break actions.
A handgun is a firearm designed to be usable with only one hand. It is distinguished from a long gun which needs to be held by both hands and braced against the shoulder. Handguns have shorter effective ranges compared to long guns, and are much harder to shoot accurately. While most early handguns are single-shot pistols, the two most common types of handguns used in modern times are revolvers and semi-automatic pistols, although other handguns such as derringers and machine pistols also see infrequent usage.
The following are terms related to firearms and ammunition topics.
Robert Hillberg was a firearm designer and the head of Research & Development at the High Standard Manufacturing Company. His designs included the folding shotgun stock, the Whitney Wolverine lightweight pistol, Wildey .45 gas-operated pistol, COP .357 Derringer pistol, and M60 machine gun. Hillberg developed a variety of insurgency weapons, primarily multiple barrel shotguns, which could be covertly distributed to partisan forces fighting in the United States' national interests. Gun Digest editors have described Hillberg as a "national treasure."
A multiple-barrel firearm is any type of firearm with more than one gun barrel, usually to increase the rate of fire or hit probability and to reduce barrel erosion or overheating.
Colt Defender Mark I was an American multi-barreled shotgun intended for law enforcement or military use, completed in 1967. The shotgun was essentially a volley gun with eight single-shot barrels — each chambered for the 20-gauge 3-inch magnum shell — arranged in a octagonal fashion around the central axis, and could fire eight individual times like a semi-automatic action without the complexity of actually being a semi-automatic firearm. The action ran on a revolver-like rotating striker mechanism. The gun had a detachable buttstock and a pistol grip with a double-action trigger, and had a separate foregrip up front for instinctive shooting.
A repeating firearm or repeater is any firearm that is capable of being fired repeatedly before having to be manually reloaded with new ammunition into the firearm.
