Firearms Glossary

By + John P. Silvaggio

• Action - All moving parts that involve the loading, unloading, and firing of the gun.


• Autoloader - The name given to handguns without a revolving cylinder.


• Automatic - A firearm that will continue to shoot while the trigger is depressed and ammunitiion is available.


• Backstop - The barrier behind the target at the range that stops the bullets. This area should be free from debris to prevent ricochets.


• Barrel - The metal tube which applies a spiral to the bullet to stablize it's flight.


• Bullet - One cart of a cartridge


• Butt - The part of the firearm located on the rear end of the frame which is grasped by the hand.


• Caliber - The diameter measure from the bore of the gun barrel, cartridge case, or bullet measured in hundredths or thousandths of an inch or in millimeters.


• Cartridge - The complete capsule composed of a case, gun powder, primer, and bullet.


• Case - The metallic body of a cartridge.


• Centerfire - A cartridge which has the primer located in the center of the case's rear


• Chamber - In revolvers, the portion of the handgun where the cartridge is placed when loaded. In semi-automatics, the interior of the barrel's rear where the cartridge is seated.


• Clip - A device used to store multiple cartridges. This is also referred to as a magazine.


• Cocking - The act of forcing the hammer against the mainspring.


• Cylinder - The magazine of a revolver which holds the cartridges.


• Double-action - Describes the type of action of a firearm where the hammer can be cocked and released in a single squeeze of the trigger.


• Ejector Rod - The rod that is used to unload the cartridges and/or cases from a firearm.


• Ejector - In a semi-automatic, it is a stationary pin that pushes cartridges cases out of and away from the pistol during the recoil process. In a revoler, the device often a star in shape connected to the Ejector Rod to assist in cartridge removal.


• Extractor - A device to remove the fired cartridge cases from the chamber in revolvers or to pull the empty case clear of the barrel in sem-automatics.


• Firearm - A device that utilizes internal combustion to induse the flight of a bullet. It is a general term that includes handguns, pistols, revolvers, rifles, or shotguns.


• Firing Pin - The part of a firearm's action assembly that is driven by the force of the hammer into the primer causing the primer to to detonate and ignite the powder.


• Frame - The metal housing of a handgun. This is the root of a handgun which all parts stem.


• Full-Cock - The condition of a firearm when the mainspring is completely compressed.


• Grip - The act of placing ones hand(s) on the firearm. It is also used to reference the butt of a firearm.


• Gun - A general term for firearm.


• Half-cock - The condition of a handgun when the hammer is pulled only partition against the mainspring and is caught by a retaining notch.


• Hammer - The part of an action assembly that is driven by the mainspring that strikes the Firing Pin.


• Handgun - A firearm designed to be fired by either one or two hands.


• Load - the act of putting a complete cartridge into the chamber. In a semi-automatic this is accomplished by cycling the action.


• Machine Gun - the term given to a firearm which will continuously load and fire while the trigger is depressed.


• Magazine - the part of the firearm where the cartridges are stored. On a semi-automatic the magazine is usually removable.


• Magnum - A term used to indicate a cartridge/firearm is designed for a higher muzzle velocity. NOTE: do not load magnum rounds in a non-magnum firearm e.g. loading a .44 magnum in a .44 special may cause injury.


• Mainstring - the spring which drives the firing pin of the handgun. This is part of the action assembly.


• Muzzel - The front end of the bore, where the bullet exits the barrel.


• Patridge Sight - a type of handgun sight with a semi-rectangular shape.


• Pistol - a general term for any type of handgun. This is more commonly used for semi-automatic's


• Primer - The part of a cartridge that when struck ignites the gunpowder.


• Range - the term used to determine the absolute distance a bullet will travel before losing all of its momentum.


• Recoil - the reverse motion of a firearm caused by the detonation of cartridges.


• Revolver - A handgun which using a revolving cylinder. This term was developed by Samuel Colt when he called his invention a 'revolving pistol'


• Rifling - The Spiral grooves cut into the bore which applies a spin to the bullet to help stabilize it's flight.


• Rim - The flanged ridge around the cartridge's base which gives the extractor hook a hold on the case.


• Rimfire - a type of cartridge where the primer is placed in a ring within the cartridge rather than located in the center.


• Round - Commonly used in reference to a cartridge.


• Safety - A movable part on some handguns that permits or prevents the weapon from firing.


• Sear - The part of a semi-automatic which prevents more then one shot from being fired.


• Semi-Automatic - A term given to a handgun that will fire one round for every time the trigger is depressed.


• Sight - The device of the firearm used to aim the firearm.


• Sight Radius - The distance between the front and rear sights. NOTE: The longer the radius the more accurate it will be.


• Single-Action - A type of firearm where the pulling of the trigger will only release the hammer. The hammer must be manually cocked.


• Slide - The part of the action on a semi-automatic which moves back and forth to eject an empty case and reload a loaded cartridge from the magazine.


• Spur - The projection on the hammer during the pull of the cock