Submachine gunA submachine gun (SMG) is a magazine-fed automatic carbine designed to fire handgun cartridges. The term "submachine gun" was coined by John T. Thompson, the inventor of the Thompson submachine gun, to describe its design concept as an automatic firearm with notably less firepower than a machine gun (hence the prefix "sub-"). As a machine gun must fire rifle cartridges to be classified as such, submachine guns are not considered machine guns. The submachine gun was developed during World War I (1914–1918) as a close quarter offensive weapon, mainly for trench raiding.
Bolt actionBolt-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 firearm (as most users are right-handed). Most bolt-action firearms use a rotating bolt design, where the handle must first be rotated upward to unlock the bolt from the receiver, then pulled back to open the breech and allowing any spent cartridge case to be extracted and ejected.
Magazine (firearms)A magazine, or simply called mag, is an ammunition storage and feeding device for a repeating firearm, either integral within the gun (internal/fixed magazine) or externally attached (detachable magazine). The magazine functions by holding several cartridges within itself and sequentially pushing each one into a position where it may be readily loaded into the barrel chamber by the firearm's moving action.
Armour-piercing ammunitionArmour-piercing ammunition (AP) is a type of projectile designed to penetrate either body armour or vehicle armour. The first major application of armour-piercing projectiles was to defeat the thick armour carried on many warships and cause damage to their lightly armoured interiors. From the 1920s onwards, armour-piercing weapons were required for anti-tank warfare. AP rounds smaller than 20 mm are intended for lightly armoured targets such as body armour, bulletproof glass, and lightly armoured vehicles.
AK-47The AK-47, officially known as the Avtomat Kalashnikova (Автомат Калашникова; also known as the Kalashnikov or just AK), is a gas-operated assault rifle that is chambered for the 7.62×39mm cartridge. Developed in the Soviet Union by Russian small-arms designer Mikhail Kalashnikov, it is the originating firearm of the Kalashnikov (or "AK") family of rifles. After more than seven decades since its creation, the AK-47 model and its variants remain one of the most popular and widely used firearms in the world.
Single-shotIn 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.
Primer (firearms)In firearms and artillery, the primer (ˈpraɪmər) is the chemical and/or device responsible for initiating the propellant combustion that will propel the projectiles out of the gun barrel. In early black powder guns such as muzzleloaders, the primer was essentially the same chemical as the main propellant (albeit usually in a finer-powdered form), but poured into an external flash pan, where it could be ignited by an ignition source such as a slow match or a flintlock, though some muzzleloaders have primers like cap gun caps.
RiflingIn firearms, rifling is machining helical grooves into the internal (bore) surface of a gun's barrel for the purpose of exerting torque and thus imparting a spin to a projectile around its longitudinal axis during shooting to stabilize the projectile longitudinally by conservation of angular momentum, improving its aerodynamic stability and accuracy over smoothbore designs. Rifling is characterized by its twist rate, which indicates the distance the rifling takes to complete one full revolution, such as "1 turn in 10 inches" (1:10 inches), "1 turn in 254 mm" ("1:254 mm" or "1:25.
RecoilRecoil (often called knockback, kickback or simply kick) is the rearward thrust generated when a gun is being discharged. In technical terms, the recoil is a result of conservation of momentum, as according to Newton's third law the force required to accelerate something will evoke an equal but opposite reactional force, which means the forward momentum gained by the projectile and exhaust gases (ejectae) will be mathematically balanced out by an equal and opposite momentum exerted back upon the gun.
Centerfire ammunitionA centerfire cartridge is a firearm metallic cartridge whose primer is located at the center of the base of its casing (i.e. "case head"). Unlike rimfire cartridges, the centerfire primer is typically a separate component seated into a recessed cavity (known as the primer pocket) in the case head and is replaceable by reloading. Centerfire cartridges have supplanted the rimfire variety in all but the smallest cartridge sizes. The majority of today's handguns, rifles, and shotguns use centerfire ammunition, with the exception of some .
