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 machine pistol is an autoloading pistol capable of fully automatic fire, including stockless handgun-style submachine guns.
A semi-automatic rifle is an autoloading rifle that fires a single cartridge with each pull of the trigger and uses part of the fired cartridge's energy to eject the case and load another cartridge into the chamber. In contrast, a bolt-action rifle requires the user to cycle the bolt manually before they can fire a second time, and a fully automatic rifle fires continuously until the trigger is released.
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.
The Colt AR-15 is a lightweight, magazine-fed, gas-operated semi-automatic rifle. It is a semi-automatic version of the M16 rifle sold for the civilian and law enforcement markets in the United States. The AR in AR-15 stands for ArmaLite rifle, after the company that developed it in the 1950s. Colt's Manufacturing Company currently owns the AR-15 trademark, which is used exclusively for its line of semi-automatic AR-15 rifles.
A semi-automatic firearm, also called a self-loading or autoloading firearm, is a repeating firearm whose action mechanism automatically loads a following round of cartridge into the chamber and prepares it for subsequent firing, but requires the shooter to manually actuate the trigger in order to discharge each shot. Typically, this involves the weapon's action utilizing the excess energy released during the preceding shot to unlock and move the bolt, extracting and ejecting the spent cartridge case from the chamber, re-cocking the firing mechanism, and loading a new cartridge into the firing chamber, all without input from the user. To fire again, however, the user must actively release the trigger, allow it to "reset", before pulling the trigger again to fire off the next round. As a result, each trigger pull only discharges a single round from a semi-automatic weapon, as opposed to a fully automatic weapon, which will shoot continuously as long as the ammunition is replete and the trigger is kept depressed.
A semi-automatic pistol is a handgun that automatically ejects and loads cartridges in its chamber after every shot fired. 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.
The Heckler & Koch G11 is a non-production prototype assault rifle developed from the late 1960s–1980s by Gesellschaft für Hülsenlose Gewehrsysteme (GSHG), a conglomeration of companies headed by firearm manufacturer Heckler & Koch, Dynamit Nobel, and Hensoldt Wetzlar. The rifle is noted for its use of caseless ammunition.
An automatic firearm or fully automatic firearm is an autoloading firearm that continuously chambers and fires rounds when the trigger mechanism is actuated. The action of an automatic firearm is capable of harvesting the excess energy released from a previous discharge to feed a new ammunition round into the chamber, and then igniting the propellant and discharging the projectile by delivering a hammer or striker impact on the primer.
Selective fire, or select fire, is the capability of a weapon to be adjusted to fire in semi-automatic, fully automatic, and/or burst mode. The modes are chosen by means of a selector switch, which varies depending on the weapon's design. Some selective-fire weapons have burst fire mechanisms to limit the maximum number of shots fired automatically in this mode. The most common limits are two or three rounds per trigger pull. Fully automatic fire refers to the ability for a weapon to fire continuously until either the feeding mechanism is emptied or the trigger is released. Semi-automatic refers to the ability to fire one round per trigger pull.
Pump action is a type of manual firearm action that is operated by moving a sliding handguard on the gun's forestock. When shooting, the sliding forend is pulled rearward to eject any expended cartridge and typically to cock the hammer or striker, and then pushed forward to load a new cartridge into the chamber. Most pump-action firearms use an integral tubular magazine, although some do use detachable box magazines. Pump-action firearms are typically associated with shotguns, although it has been used in rifles, grenade launchers, as well as other types of firearms. A firearm using this operating mechanism is colloquially referred to as a pumpgun.
A semi or full-automatic firearm which is said to fire from a closed bolt is one where, when ready to fire, a round is in the chamber and the bolt and working parts are forward. When the trigger is pulled, the firing pin or striker fires the round; the action is cycled by the energy of the shot, sending the bolt to the rear, which extracts and ejects the empty cartridge case; and the bolt goes forward, feeding a fresh round from the magazine into the chamber, ready for the next shot.
The Special Purpose Individual Weapon (SPIW) was a long-running United States Army program to develop, in part, a flechette-firing "rifle", though other concepts were also involved. The concepts continued to be tested under the Future Rifle Program and again in the 1980s under the Advanced Combat Rifle program, but neither program resulted in a system useful enough to warrant replacing the M16.
The USP is a semi-automatic pistol developed in Germany by Heckler & Koch GmbH (H&K) as a replacement for the P7 series of handguns.
The Heckler & KochP7 is a German 9×19mm semi-automatic pistol designed by Helmut Weldle and produced from 1979 to 2008 by Heckler & Koch GmbH (H&K). The P7M13, a variant of the P7 with a double-stack magazine, was produced until 2000.
The Heckler & Koch HK33 is a 5.56mm assault rifle developed in the 1960s by West German armament manufacturer Heckler & Koch GmbH (H&K), primarily for export.
A trigger is a mechanism that actuates the function of a ranged weapon such as a firearm, airgun, crossbow, or speargun. The word may also be used to describe a switch that initiates the operation of other non-shooting devices such as a trap, a power tool, or a quick release. A small amount of energy applied to the trigger leads to the release of much more energy.
The Heckler & KochG41 is a German 5.56×45mm NATO assault rifle introduced in 1981 and produced in limited quantities by Heckler & Koch. It was designed to replace the 7.62×51mm NATO chambered Heckler & Koch G3 and the G3 based .223 Remington/5.56×45mm and later 5.56×45mm NATO chambered Heckler & Koch HK33 service rifles providing a more modern weapon compatible with then recently introduced NATO standards. It can use both the then new STANAG 4172 compliant 5.56×45mm NATO SS109, SS110, and SS111 ammunition and older .223 Remington/5.56×45mm M193 ammunition and was the last Heckler & Koch service rifle designed around the roller-delayed blowback mechanism.
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.
