Glossary of Firearm Terms

If you’re new to the shooting sports, hunting or firearm ownership, there can be a lot to learn, especially when it
comes to all the terminology whether we’re talking parts of a firearm, ammunition or types of shooting sports. To
help you begin building your basic firearms knowledge, we defined the following common terms, including parts
of the firearm and some associated elements. Check back for additional glossaries that will explain elements of
shooting such as ballistics, cartridges, gear and more.

Action: The part of the firearm that works to feed a round into the chamber, facilitates firing the round, and
ejects the spent shell or cartridge after the round is fired. There are a number of different actions, especially
when it comes to long guns such as rifles or shotguns. These include lever-actions, semi-autos, single shots and

Backstrap: This is the back part of the grip of a handgun.

Barrel: The barrel is the metal tube-like part of the gun, either rifled or smooth, the bullet travels through when
first fired.

Bolt-Action: A rifle or shotgun that has a protruding handle (bolt) that the shooter uses to feed and lock a cartridge into the chamber so the gun can be fired. It is then used to eject and remove the spent casing and load another.

Bore: Inside of the barrel and often affects the size of bullet or cartridge that can be fired from the gun.

Butt: The rear portion of the stock on a rifle or shotgun or the bottom part of a pistol grip.

Butt Plate: A covering that protects the butt of a firearm. It can be made of rubber, plastic, metal or other materials.

Caliber: This is the diameter of a bullet fired from a barrel with rifling such as a rifle or handgun. It must match the diameter of the interior of the barrel. It is typically expressed in hundreds of an inch.

Choke: This is a tightening, or more commonly constriction, of a shotgun’s muzzle that determines how tightly or loosely the shot fired from a shotshell will disperse after being fired. Common choke constrictions from loosest to tightest is cylinder, improved cylinder, modified, full and extra full.

Comb: The part of a rifle or shotgun’s stock where the shooter’s check rests as they aim and prepare to fire.

Cylinder: The drum-shaped part of a revolver where cartridges are loaded. The cylinder rotates as each round is fired or as the revolver is cocked.

Forearm or Forend: The part of the stock located under a firearm’s barrel where the shooter’s forward hand holds the firearm steady.

Gauge: Like caliber, this is how the size of the barrel’s bore is expressed. The smaller the number, the larger the bore (i.e., a 10-gauge shotgun’s bore is twice the size in diameter of a 20-gauge’s bore).

Note: Originally, gauge was measured by determining the number of lead balls that fit in the diameter of the bore and the portion of a pound it weighed.

Grip: The part of the gun’s handle held by the shooter’s hand on a handgun as well as the part where the rear hand grips on the narrow part of the stock on a rifle or shotgun.

Hammer: The part of the firearm that slams forward upon depression of the trigger, striking the cartridge’s primer or a firing pin.

Lever-Action: A type of rifle whereby a lever is worked to feed new cartridges and expel fired shells from the chamber.

Magazine or Mag: Can be either a permanent part of the firearm, but most often is detachable, and holds the cartridges to be fired. Magazines are typically spring loaded to feed a new cartridge into the chamber after the previous round has been fired and is being unloaded.

Magazine Well: For a detachable magazine, this is the opening in a firearm where the magazine is inserted.

Muzzle: A gun barrel’s open end where a bullet exits when fired.

Pump-Action: Most often found on a modern shotgun more so than rifles. It is an action type that feeds new cartridges and expels spent ones via a slide located on the forend of the firearm.

Revolver: This is a pistol with a rotating cylinder that holds cartridges and rotates to line up each chamber with a barrel and firing pin.

Rifling: Refers to spiral grooves cut into a gun’s bore that cause the bullet to spin for better downrange accuracy when it is fired.

Safety: Designed to prevent the trigger from being pulled or the gun fired when not intended.

Note: Even with a safety engaged, the finger should stay off the trigger, outside the trigger guard, until the sights are on the target and the person is ready to shoot.

Shotgun: A long gun typically with a smooth-bored barrel that is held to the shoulder to be fired and holds shotshells instead of cartridges in order to send multiple projectiles (shot) downrange. For this reason, shotguns do not possess the long-range capabilities of a rifle.

Single Shot: A type of gun where only a single cartridge or shotshell can be loaded and fired at a time and then manually removed after firing.

Sling: A strap often attached to a rifle or shotgun so the firearm can be slung over a person’s shoulder, making it easier to carry.

Sling Swivel: These provide the spot — on or near the forend and on the stock — where the sling attaches.

Stock: The part of the firearm the action and barrel fit into, which the shooter holds and/or shoulders in order to shoot the firearm. Most often, firearms that have a stock are long guns (rifles or shotguns), but a pistol could have a wooden stock and grip (these are usually for hunting, often used by hunters with physical restrictions).

Trigger: The manually operated part of the firearm that when squeezed trips the hammer and initiates firing of the gun.