A long gun is a category of firearms with longer barrels than most other types. In small arms, a long gun is generally designed to be held by both hands and braced against the shoulder, in contrast to a handgun, which can be fired being held with a single hand. In the context of cannons and mounted firearms an artillery long gun would be contrasted with a howitzer or carronade.
Recoil is the backward movement of a gun when it is discharged. In technical terms, the recoil momentum acquired by the gun exactly balances the forward momentum of the projectile and exhaust gases (ejecta), according to Newton's third law, known as conservation of momentum. In hand-held small arms, the recoil momentum is transferred to the ground through the body of the shooter; while in heavier guns such as mounted machine guns or cannons, recoil momentum is transferred to the ground through the mount.
A gun barrel is a crucial part of gun-type ranged 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 introduced behind a projectile in order to propel it out of the front end (muzzle) at a high velocity. The hollow interior of the barrel is called the bore. The measurement of the diameter of the bore is called the caliber. Caliber is usually measured in inches or millimetres.
Mossberg 500 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.
Rate of fire is the frequency at which a specific weapon can fire or launch its projectiles. It is usually measured in rounds per minute, or rounds per second.
Accurizing is the process of improving the accuracy and precision of a 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 first gas-operated rifle was designed in 1883–1884 by Karel Krnka.
The Mark 48, or Mk 48 is a lightweight belt-fed machine gun, firing 7.62×51mm NATO cartridges from a disintegrating belt of ammunition.
The HK33 is a 5.56mm assault rifle developed in the 1960s by West German armament manufacturer Heckler & Koch GmbH (H&K), primarily for export.
The A-91 is a bullpup assault rifle developed during the 1990s by KBP Instrument Design Bureau in Tula, Russia as an offspring of the 9A-91 firearm family. While the A-91 retains the basic gas-operated, rotating bolt action and a trigger unit design from 9A-91, it features a bullpup polymer housing, with an integral 40 mm single-shot grenade launcher mounted under the barrel. The earliest prototypes of the A-91 bullpup were fitted with the grenade launcher above the barrel, and with a front vertical foregrip; current models are fitted with the underbarrel launcher, which also serves as a forearm. The A-91 features a forward ejection system, initially developed in Tula by designers like Afanasiev during the early 1960s. In this system, the ejection port is located above the pistol grip, and points forward. Extracted cases are fed from bolt head through the short ejection tube to the ejection port, and fall out of the gun well clear of the shooter's face, even when firing from the left shoulder. As for now, the A-91 is made in small number and, probably, is used by some elite law enforcement units in Russia; it is also offered for export and domestic military and police sales.
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 top-break actions.
The M6 Air Crew Survival Weapon was a specially-made .22 Hornet over .410 bore combination gun issued to United States Air Force aircrews to help forage for food in the event of a plane crash. It was issued from 1952 until the early 1970s, in conjunction with the M4 Survival Rifle. Plans to replace both with the ArmaLite AR-5 never came to fruition.
A barrel shroud is a covering attached to the barrel of a firearm that partially or completely encircles the barrel, which prevents operators from injuring themselves on a hot barrel. Slides, extensions of the stock that do not fully encircle the barrel, and the receiver of a firearm itself are generally not described as barrel shrouds, though they in fact do act as such. Barrel shrouds are commonly featured on air-cooled machine guns, where sustained rapid or automatic fire leave the barrel extremely hot and dangerous to the operator. However, shrouds can also be utilized on semi-automatic firearms, as even a small number of shots can heat up a barrel enough to injure an operator in certain circumstances.
The Remington Model 504 is a bolt-action rimfire rifle that can chamber .22 LR, .17 HM2 or .17 HMR cartridges. The gun is a replacement of the now obsolete Remington Model 541, and was itself replaced by the Remington Model 547 in 2007. The Model 504T was a target variant built in 2006 that differed from the original 504 in using a laminated wood stock with a raised comb, a target style forearm and a heavier barrel.
The Springfield Armory M6 Scout is a .22 Hornet over .410 bore combination gun that is virtually identical to the original M6 Aircrew Survival Weapon. It is also made in .22 Long Rifle over .410 bore and .22 Magnum over .410 bore. The Scouts were made with 18.25 inches (46.4 cm) barrels, as opposed to the original's 14 inches (36 cm) barrel length, to comply with National Firearms Act. The later models had large over-sized trigger guards and Picatinny rails for mounting a wide range of sights and scopes. They come in stainless steel or with a Parkerized finish.
A gun is a ranged weapon typically designed to pneumatically discharge projectiles that are solid but can also be liquid or even charged particles and may be free-flying or tethered.
The Remington Adaptive Combat Rifle is a modular semi-automatic rifle designed by Magpul Industries of Austin, Texas, and known initially as the Masada.
The Winchester Model 1903 was the first commercially available semi-automatic firearm made by the Winchester Repeating Arms Company.
The Smith & Wesson Model 320 was a revolving rifle produced by Smith & Wesson in the late 19th century.
