A firearm is any type of gun designed to be readily carried and used by an individual. The term is legally defined further in different countries.
A machine gun is a rapid-firing, rifled long-barrel autoloading firearm designed for sustained direct fire with full-powered cartridges. Other automatic firearms such as assault rifles and automatic rifles are really designed more for unleashing short bursts rather than continuous firepower, and not considered machine guns. Squad automatic weapons, which fire the same cartridge used by the other riflemen from the same combat unit, are functionally light machine guns though not called so. Submachine guns, which are capable of continuous rapid fire but using handgun cartridges, are also not technically regarded as true machine guns.
Single-shot firearms are firearms that hold only a single round of ammunition, and must be reloaded after each shot. The history of firearms began with single-shot designs, and many centuries passed before multi-shot repeater designs became commonplace. Single-shot designs are less complex than revolvers or magazine-fed firearms, and many single-shot designs are still produced by many manufacturers, in both cartridge- and non-cartridge varieties, from zip guns to the highest-quality shooting-match weapons.
Bolt action is a type of manual firearm action that is operated by directly manipulating the bolt via a bolt handle, which is most commonly placed on the right-hand side of the weapon.
In firearms terminology, an action is the functional mechanism of a breech-loading weapon that handles the ammunition, or the method by which that mechanism works. Actions are technically not present on muzzleloaders, as all those are single-shot weapons with a closed off breech and the ammunition is manually loaded through the muzzle. Instead, the muzzleloader ignition mechanism is referred to as the lock.
A semi-automatic pistol is a type of repeating single-chamber handgun (pistol) that automatically cycles its action to insert the subsequent cartridge into the chamber (self-loading), but requires manual actuation of the trigger to actually discharge the following shot. As a result, only one round of ammunition is fired each time the trigger is pulled, as the pistol's fire control group disconnects the trigger mechanism from the firing pin/striker until the trigger has been released and reset.
Blowback is a system of operation for self-loading firearms that obtains energy from the motion of the cartridge case as it is pushed to the rear by expanding gas created by the ignition of the propellant charge.
A breechblock is the part of the firearm action that closes the breech of a weapon at the moment of firing.
The PM-63 RAK is a Polish 9×18mm submachine gun, designed by Piotr Wilniewczyc in cooperation with Tadeusz Bednarski, Grzegorz Czubak and Marian Wakalski. The RAK combines the characteristics of a self-loading pistol and a fully automatic submachine gun.
Gas-operation is a system of operation used to provide energy to operate locked breech, autoloading firearms. In gas-operation, a portion of high-pressure gas from the cartridge being fired is used to power a mechanism to dispose of the spent case and insert a new cartridge into the chamber. Energy from the gas is harnessed through either a port in the barrel or a trap at the muzzle. This high-pressure gas impinges on a surface such as a piston head to provide motion for unlocking of the action, extraction of the spent case, ejection, cocking of the hammer or striker, chambering of a fresh cartridge, and locking of the action.
The Jatimatic is a Finnish 9 mm submachine gun developed in the late 1970s and early 1980s by Jali Timari. The submachine gun made its debut in 1983. The Jatimatic was manufactured in very limited numbers initially by Tampereen Asepaja Oy of Tampere and later—Oy Golden Gun Ltd. The firearm was designed primarily for police, security forces and armored vehicle crews. It was never adopted into service by the Finnish Defence Forces, although the later GG-95 PDW version was tested by the FDF in the 1990s.
In firearms, an extractor is a part in a breechloading weapon that serves to remove casings of previously fired cartridges from the chamber, so new rounds of ammunition can be loaded for firing. In repeating firearms with moving bolts, the extractor is often aided by an ejector, which expels the casings entirely out of the gun.
A trigger is a mechanism that actuates the firing sequence of a firearm, airgun, crossbow, or speargun. A trigger may also start other non-shooting mechanisms such as a trap, a switch or a quick release. A small amount of energy applied to the trigger causes the release of much more energy.
Locked breech is the design of a breech-reloading firearm's action. This is important in understanding how a self-reloading firearm works. In the simplest terms, the locked breech is one way to slow down the opening of the breech of a self-reloading firearm when fired. The source of power for the movement is recoil.
Break action is a type of firearm action in which the barrel or barrels 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-barrelled shotguns, double rifles and combination guns, and are also common in single shot rifles, pistols, and shotguns, and can also be found in 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 muzzle booster or recoil booster is a device fixed to the muzzle of a firearm, intended to harness the energy of the escaping propellant to augment the force of recoil on portions of the firearm. Muzzle boosters are usually used to improve the reliability and/or rate of fire of a recoil operated firearm. The muzzle booster is distinct from the muzzle brake, which is designed to use the propellant gases to reduce the recoil of the firearm. However, unlike a muzzle brake, a muzzle booster uses the pressure of the expanding gases, rather than the reaction force, and it does not alter the felt recoil of the weapon, it merely adds more energy to the operating components.
The following are terms related to firearms and ammunition topics.
In firearms, a safety or safety catch is a mechanism used to help prevent the accidental discharge of a firearm, helping to ensure safer handling.
Recoil operation is an operating mechanism used to implement locked-breech, autoloading firearms. Recoil operated firearms use the energy of recoil to cycle the action.
A repeating firearm is any firearm, either a handgun or a long gun, that is capable of repeated firing before needing to manually reload new ammunition into the gun. These firearms are breechloading by nature. Different to the preceding single-shot firearms, a repeating firearm can store multiple cartridges inside a magazine, a cylinder or a belt, and uses a moving action to manipulate each of these cartridges into and out of battery position, allowing the gun to discharge numerous times in relatively quick succession before a manual ammunition reload is needed.
