Glossary Of Firearms Terminology

  • Action - The moving parts of a firearm.
  • Ammunition - Cartridges.
  • Arm- A weapon of any sort.
  • Automatic - A firearm which continues to fire as long as the trigger is held down.
  • Ball - A spherical projectile for use in antique firearms. Also military ammunition is often referred to as ball ammo, hard ball, pistol ball etc. even though it is not spherical.
  • Barrel - The tube down which the bullet is driven by the propellant.
  • Black Powder - A mixture of sulpher, charcoal and saltpeter. Also known as gunpowder.
  • Bore - The hole down the center of a barrel through which the projectile passes.
  • Break Action - A type of firearm having a hinged barrel which when folded or "broken" at the hinge exposes the chamber for loading and unloading.
  • Breech - The back end of the barrel where the bullets go in, as opposed to the muzzle where the bullets come out.
  • Bullet - A projectile. Sometimes a cartridge is called a bullet, but this is incorrect.
  • Burst - Two or more (often three) rounds fired from an automatic or select-fire weapon with a single pull of the trigger.
  • Cannon - Originally a large tube, now a large mounted gun. An artillery piece.
  • Cartridge - A round of assembled ammunition. The case, primer, powder, and bullet.
  • Cartridge Case - The major component of a cartridge. It holds the primer, powder and bullet together.
  • Case - Short for cartridge case.
  • Centerfire - A cartridge with the primer in the center of the base of the cartridge case. Also a firearm chambered for centerfire ammunition.
  • Chamber - The location in the breech of a firearm where the cartridge is loaded in order to be fired.
  • Cock - Put the firing mechanism under spring tension in preparation of it being released by the trigger to fire the gun.
  • Cocked - When the hammer or striker is under spring tension and ready to fire.
  • Detachable Magazine - A magazine which can be easily removed and replaced for the purpose of unloading, reloading, or replacement with a full magazine.
  • Discharge - Shoot. Fire.
  • Double Action - A firearm that can be cocked and fired with the trigger, as opposed to a single action which must be cocked independently of the trigger. Many double actions can also be fired in single action mode. Typically this term is only applied to handguns.
  • Double Action Only (DAO) - A double action firearm that must be cocked and fired with the trigger and can not be fired in single action mode.
  • Double Feed - A case where the action is trying to chamber more than one round at the same time.
  • Downrange - In the direction of intended fire. Toward the target.
  • Drum Magazine - A typically detachable magazine wherein the cartridges wrap around in a circle or a spiral. Drum Magazines usually hold many rounds, often 100 or more.
  • Fire - Discharge. Shoot.
  • Firearm - A gun. Note: Massachusetts defines firearm as a handgun.
  • Firing Pin - The component that strikes the primer on a chambered cartridge.
  • Fixed Magazine - A magazine which is not normally removed from the firearm.
  • Flint - A mineral that creates sparks when struck against steel.
  • Flintlock - A lock which uses flint on steel ignition. A firearm with such a lock.
  • Gun - For the purposes of this site, a firearm. Generally speaking a device that shoots any kind of projectile. Pellet gun, BB gun, nail gun, dart gun, staple gun, electron gun, ray gun, etc.
  • Gunpowder - A mixture of sulpher, charcoal and saltpeter. Also known as black powder.
  • Hammer - The part of a firearm that is driven by spring tension when released by the trigger and provides the energy to detonate the primer. A hammer pivots as opposed to a striker, which moves axially. Some firearms have external hammers, some have internal hammers and some have strikers instead of hammers.
  • Half Cock - A hammer position between un-cocked (hammer down) and cocked (full cock). The trigger will not release the hammer from this position. Half Cock is used to get the hammer out of the way while performing some operation (loading a single action revolver, for example), but without the danger of accidentally releasing the hammer with the trigger. Some firearms have more than one "half cock" position, others have none.
  • Lock - The firing mechanism. Not usually applied to modern firearms.
  • Lock Time - The time between pulling the trigger and the ignition of the main powder charge.
  • Long Gun - A rifle, musket or shotgun. A shoulder fired gun as opposed to a handgun.
  • Magazine - The part of a firearm intended to store cartridges to be fed into the chamber by the action.
  • Match - A smouldering piece of cord used to fire a matchlock firearm.
  • Matchlock - A firing system that uses a match to ignite the priming powder. Also a firearm with such a system.
  • Muzzle - The end of the barrel where the bullet comes out.
  • Nipple - A hollow tube projecting from the barrel on which is placed a percussion cap.
  • Percussion Cap - A small metal cup containing an impact-sensitive explosive. When placed over the nipple and struck by the hammer it lights the main powder charge.
  • Pistol - A handgun. Sometimes a handgun that is not a revolver.
  • Prime - Place powder in the priming pan, or place a percussion cap on the nipple, or insert a primer into a cartridge case.
  • Primer - An impact sensitive explosive used to ignite the main powder charge in a firearm. Also such an explosive together with its metal cup and anvil.
  • Priming Pan - A small shelf next to the touch hole where priming powder is placed.
  • Projectile - A ball, bullet, or shot.
  • Propellant - Gunpowder, Black Powder, or Smokeless Powder
  • Pump Action - A firearm action worked by pulling the fore grip back to open the bolt and eject any chambered rounds or cases, and pushing it forward again to chamber a round and make the gun ready to shoot.
  • Range - A place where shooting is taking place. Also the maximum distance a gun can shoot. Also the distance to a target.
  • Repeater - A firearm with a magazine, from which a new round is loaded when the action is worked, as opposed to a single shot.
  • Revolver - A handgun with a rotating cylinder that holds cartridges to be fired. Cocking the gun rotates the next cartridge into position, usually at the top, where it aligns with the barrel.
  • Rifle - A long gun with a rifled barrel
  • Rifling - Spiral grooves cut in the bore of a barrel in order to impart spin on the bullet.
  • Rimfire - A cartridge whose primer is in the rim of the case as opposed to the center of the case.
  • Round - An assembled cartridge. Example: "Use a 20 round magazine." Also a projectile. Example: "Did you put all 20 rounds on target?"
  • Sear - The component that holds the hammer or striker in the ready to fire position. In its most basic form the sear is part of the trigger.
  • Select Fire - A firearm with a mechanism which can be set to fire in one of two or three modes: Semi-Auto, Full Auto, or Burst.
  • Semi-Automatic - A firearm that uses part of the energy of the fired round to eject the empty cartridge case and load a new one from the magazine, usually cocking the firing mechanism as well.
  • Serpentine - The hammer-like arm on a matchlock that holds the match.
  • Shotgun - A typically smooth-bore gun designed to fire many small pellets at one time as opposed to a single bullet.
  • Single Action - A firearm whose trigger is used only to fire the gun and must be cocked by some other means. Typically this term is only applied to handguns, although most long guns also work this way.
  • Single Shot - A firearm with no magazine and thus requiring each round to be loaded by hand, as opposed to a repeater.
  • Smooth-bore - An un-rifled barrel. A firearm with an un-rifled barrel.
  • Stock - The part of a firearm intended as a means of holding on to said firearm. Often made of wood but increasingly synthetic. 
  • Stove Pipe - A case where an empty case or a live round is stuck in the action at a right angle to the bore.
  • Striker - The part of a firearm that is driven by spring tension when released by the trigger and provides the mechanical energy to detonate the primer. A striker moves axially as opposed to a hammer which pivots.
  • Touch-hole - The hole in the side of a barrel to allow the ignition of the main powder charge.
  • Trigger - The part of a firearm that is manipulated in order to discharge said firearm.
  • Tubular Magazine - A fixed magazine in the shape of a tube typically attached below the barrel.
  • Weapon - A tool used to inflict bodily harm on an enemy.
  • Wheel-lock - A firing device that uses a spinning disk to generate sparks to ignite the priming powder.