Glossary of Firearms Terminology

• Action
  Working mechanism of a firearm.  There are various types. Bolt
  Action, Lever Action, Single Action, Double Action, etc.
• Automatic
  A machine gun.  Any repeating firearm that automatically
  ejects, chambers and
  fires rounds repeatedly, usually at high speed,  with a
  single, steady pull of the trigger. Also
  called Fully Automatic.
• Backstrap
  The back of a pistol’s frame, the back of the grip.
• Ball
  A type of bullet or projectile.  Usually used in older
  firearms such as a flintlock, musket-type weapons.
• Barrel
  The strong metal tube of a firearm through which the bullet
  passes.
• Barrel-Cylinder Gap
  The clearance between the sides of a bullet and the bore of the barrel
  as the bullet travels down it when fired.  In the US, the
  industry-standard tolerance of the Barrel-Cylinder Gap is from 0.0001
  to 0.012 inches.  A gap any larger will cause problems with
  firing and accuracy.
• Black Powder
  Gunpowder.  Explosive mixture
  consisting of charcoal, sulfur and saltpeter (nitrate).
  Invented by the
  Chinese in ancient times.
• Blank or Blank Cartridge
  A cartridge that has the explosive powder charge but no projectile.
• Blowback (Blowback-Operated)
  Utilization of the force of hot, expanding
  gases released from firing the firearm.  In modern firearms,
  the
  strong force of the blowback is used to eject spent cartridges and a
  spring recoil replaces them with new ones in the
  chamber.  Also called “gas operated.”
• Blued or Blueing
  The treatment of metal on firearms that results in a black or
  bluish-black finish, usually done with chemicals.
• Blunderbuss
  Precursor to the shotgun.  Usually a flintlock weapon, shorter
  than a
  rifle or a carbine, longer than a pistol, that is identifiable by a
  large, flared funnel-like barrel.  Used for short-range
  close-in fighting, often used on ships as well as by mail and
  stagecoach drivers.  Also called a naval or pirate
  blunderbuss.  Used from late 1600s to mid 1800s.
• Bolt
  Metal bar or rod that slides and seats and/or removes a cartridge.
• Bolt-Action
  Firearm’s action, using a manual sliding and/or rotating bolt to
  operate.
• Bore
  The inside of the barrel, or other part that needs to be hollowed out.
• Breech
  The rear of the barrel.
• Breech Loader
  A firearm that is loaded at the rear of the barrel.
• Buckhorn Sight
  An open-top sight with curved sides.  Probably so-named
  because the shape  resembles antlers on a buck.
• Bullet
  Technically, the projectile portion of a cartridge that is blown off by
  detonation of the powder charge, and flies through the air toward the
  target, leaving the shell or casing behind to be ejected.
  People often refer to the entire cartridge as a
  “bullet.”  On older black powder or percussion firearms, the
  bullet was just a shaped piece of lead.
• Butt
  The very rear end of a rifle stock or the bottom of a pistol grip.
  In the Old West, the butt of a rifle or pistol was used as a
  secondary weapon by lawmen to  subdue troublemakers.
  Very handy for cracking skulls!  Sometimes referred
  to as “pistol whipping.”
• Buttplate
  On a rifle, a covering of metal, wood, plastic or other material fitted
  onto the very rear end of a rifle butt.
• Caliber
  Interior diameter of the barrel, or the bore.  Also
  corresponds to the size of ammunition that will fit in it.
• Carbine
  A rifle or musket with a short barrel, usually a military version.
• Cartridge
  A modern “bullet” or metal casing, which is an entirely self-contained
  piece of ammunition, with projectile, powder charge and ignition
  primer, all in one unit.  Nowadays, there are mainly only
  three
  kinds of cartridge: rimfire, centerfire and shotgun.
• Centerfire
  A cartridge that is detonated by striking a primer button centered in
  its base by the firing pin.  If a cartridge has what appears
  to
  be a “button” in its base end, it’s a centerfire cartridge.
• Chamber
  The rear of the barrel, or part of the gun where the ammunition is
  placed, in position, ready to fire.
• Checkering
  The crosshatched pattern or texture on a metal, wood or plastic surface
  of a firearm, usually used to improve grip, or for decoration.
  Especially used on hammers and slides and grips.
• Choke
  The shaping or an attachment at the muzzle of a shotgun that directs
  the spray or  pattern of shot as it is fired
  out.
• Clip
  A container or feeding system, usually spring-loaded, that holds
  cartridges in place, so that it can be inserted into a firearm’s
  magazine.  Sometimes, the clip is called a “magazine” or a
  removable magazine.
• Compensator
  A variation of muzzle brake that diverts escaping high-pressure gases
  upwards at the muzzle, reducing the general upward kick caused by
  recoil to compensate for it, and improve accuracy.
• Crowning
  The rounded or beveled end surfacing of the barrel opening, (muzzle)
  used to
  protect the opening and edges.
• Cylinder
  On a revolver, the rotating “wheel” that holds the cartridges, and
  allows them to rotate into position with the chamber for
  firing.
• Damascus Barrel
  On old black powder firearms, a type of barrel made usually of separate
  bands of twisted iron. If you have a firearm with a Damascus barrel, it
  is not considered safe to shoot due to age, and the fact that such
  construction will not withstand the stresses and pressures created by
  today’s ammunition.
• Deringer, Derringer
  Originally a brand of very small pocket pistol made for easy
  concealment.  Today, the term Deringer or Derringer (2 R’s) is
  used to
  refer to just about any brand of very small and concealable pocket
  pistol.
• Double Action
  A pistol or revolver that allows the hammer to be cocked and released
  by pulling the trigger.
• Dry Fire, Dry Firing
  Pulling the trigger and sending the firing pin and other parts into
  their full range of motion and impact without using
  ammunition.  Usually considered a bad thing to do,
  placing undue stress on the parts.
• Extractor
  Mechanism that removes empty ammunition casings from the chamber so
  they can be ejected clear of the firearm.
• Firing Pin
  A strong metal rod or pin that forcefully strikes the primer of a
  cartridge, firing the firearm.
• Flash Suppressor
  Attachment (or integral part of the muzzle) that covers the end of the
  muzzle, hiding the flash created by firing a firearm.
• Flintlock
  Old form of ignition for firearms in the days before fully
  self-contained cartridges.  A locking mechanism with a metal
  part that strikes a flint, producing a spark, firing the weapon.
• Frizzen
  On a flintlock firearm, a curved metal plate, usually
  hinged, which is struck
  by the hammer, which contains
  a flint. When the flint strikes the frizzen, it creates a shower of
  sparks, while springing open to expose them to the powder in the pan to
  ignite it.
• Fully Automatic or Full Automatic
  A machine gun.  Any repeating firearm that automatically
  chambers and fires rounds repeatedly with a single, steady pull of the
  trigger.  Also called Fully Automatic.
• Gas-Operated
  Utilization of the force of hot, expanding
  gases released from firing the firearm.  In modern firearms,
  the
  strong force of the blowback is used to eject spent cartridges and a
  spring recoil replaces them with new ones in the
  chamber.   Also
  called
  “blowback-operated.”
• Gauge
  The inside diameter or bore of a shotgun barrel.  A shotgun’s
  gauge is determined by a formula of how many balls of shot taken from a
  pound of metal will fit in a certain bore size.
• Grain
  Measurement unit of a powder charge.  One pound is equivalent
  to 7,000 grains of powder.  437.5 grains is equivalent to one
  ounce.
• Grip
  The handle of a revolver or pistol.  Sometimes fully
  integrated, or mounted in pieces.  Can be wood, metal,
  plastic, etc.
• Grooves
  Spiraled channels cut into the inside of a firearm’s barrel, that cause
  a bullet to spin upon firing, stabilizing its trajectory and improving
  accuracy.
• Half-Cock
  Partially cocking a firearm’s hammer so that it does not fall and set
  off the firearm.  If you slip and let the hammer fall while a
  round is chambered, you
  will discharge the firearm.
• Hammer
  Moving part that hinges up on rear (on hammer-equipped firearms), and
  snaps back into place with force, detonating the cartridge.
  Flint-tipped hammers are also used on flintlocks, to strike
  the frizzen to ignite powder.
• Hangfire
  A malfunction in the primer of a cartridge that causes a delay in
  firing after the trigger is pulled.  Obviously, if you have a
  long or ongoing hangfire or misfire, DO NOT look into the barrel to see
  what’s
  going
  on.  Some people have actually (stupidly?) died doing this!
• Hollowpoint
  Bullet with a hollow area in the nose, that causes it to expand on
  impact, increasing its destructive force.
• Jam
  Misfire, caused by a mechanical part malfunction, or by a cartridge
  being stuck midway in the magazine or chamber. Also, almost any other
  kind of mechanical blockage in the firearm.
• Lands
  Inside the barrel of a riflled firearm, the raised areas of the metal
  surface,
  that remain above the cut rifling grooves.
• Magazine
  Spring-loaded container that feeds cartridges into the firing
  chamber.  Detachable or non-detachable. Sometimes
  called a “clip.”
• Magnum
  A longer version of a cartridge of the same
  caliber.  The increased length is to accommodate more powder
  for
  increased velocity, power and range.
• Mainspring
  On a flintlock musket or rifle, a strong spring that holds the hammer
  back in the cocked position until released by pulling the trigger.
• Misfire
  When a cartridge fails to discharge, or to discharge properly.
• Musket
  A smoothbore barrel (no rifling) firearm.  Usually an old
  firearm with a flintlock firing system.
• Musketoon
  Short barrel, smoothbore, muzzle-loading carbine.  A
  short-barrel version of a musket.  Similar to a carbine.
• Muzzle
  The end of the barrel, the  opening where the bullet exits.
• Muzzle Brake
  Attachment or shaping at the muzzle to dissipate or reduce gas pressure
  in order to reduce recoil.
• Muzzle Energy
  The force (measured in foot-pounds) of a bullet exiting the muzzle.
  Similar to recoil.
• Muzzle Loader
  Firearm that is loaded through the muzzle, with a solid
  breech.  Old smoothbores are muzzle loaders.
• Pan
  On a flintlock musket or rifle, a small bowl-shaped pan that holds a
  small
  charge of powder. When
  ignited by the flint striking the frizzen, it flashes down a drilled
  hole in barrel, igniting the main charge in the barrel.
• Parabellum
  General name given to cartridges measuring 9 X 19mm.  Also the
  popular nickname  of a famous German Pistol in that same
  caliber, made by
  Deutsche Munitions Fabrik (DWF) beginning in the early 1900s.
  Parabellum is a latin word (si vis pacem, para bellum) meaning: “If you
  wish for peace, prepare for war”
• Parkerizing
  A dull gray or greenish finish on a firearm to prevent rust.
• Patchbox
  On a musket or flintlock rifle, a small compartment in the stock,
  usually with a door or lid, used
  for storing patches of greased or oiled cloth, which is rammed down
  the barrel, and used to wad or pack the
  lead ball or bullet against the powder, providing a seal for better
  compression upon firing.
• Peep Sight
  Rear sight with a small hole, which one peeps through to line up on the
  front sight and the target.
• Percussion Cap
  On older “Cap and Ball” or percussion revolvers, a small, explosive
  cap, usually placed on a “percussion nipple” that, when struck by the
  hammer, ignites the powder charge through a small hole, firing the
  weapon.
• Percussion Revolver
  An older black powder revolver, in which the hammer strikes a
  percussion cap, igniting the main powder charge.
• Pinfire
  Old, obsolete cartridge with a small
  pin protruding from the side, near the base, that when struck by the
  firing pin, ignites the main powder charge.
• Plinking
  Old and obsolete type of cartridge
  that had a small metal pin sticking out of the side, at the base, which
  when struck, would ignite the charge, firing the bullet.
• Primer
  Small charge in a cartridge that ignites the powder when struck by the
  firing pin, discharging it.
• Receiver
  The part of a firearm that contains the moving parts, or the action. In
  modern firearms, the mechanical area that loads and ejects a cartridge.
• Recoil
  The energy created by the explosive release of discharging a firearm,
  that pushes it back against the person shooting it. It can range from a
  gentle bump to a smashing, bone-jarring experience, depending on the
  firearm.  Remember what physicist Albert Einstein
  said?  “For every action, there is an equal and opposite
  reaction.”
• Revolver
  A firearm with a rotating cylinder that holds cartridges, and aligns
  them for loading, unloading and firing.
• Rifle
  Long-Barreled firearm with a rifled groove cut into the bore of the
  barrel.
• Rifling
  The grooves cut into the bore of a barrel, to cause the bullet to
  rotate when fired, improving stability and accuracy in flight.
• Rimfire
  A cartridge that has its primer in the base, and is ignited by having
  the firing pin strike the edge (rim) of the casing, crushing the rim to
  ignite it.  Modern rimfire cartridges are mainly found only in
  small calibers, such as .22 caliber.
• Round
  Informal way of saying “cartridge” or a shot.  Example; “I
  fired a couple of rounds at them.”
• Sabot or Sabot Bullet
  In firearms, sabots are
  only known to be used in old black powder guns.  A sabot is
  basically an adaptor that fits onto the back end of a bullet, to help
  trap in gases for more compression, enabling a smaller bullet to be
  used in a firearm with a larger bore or caliber.
• Safety
  A locking catch or mechanism that prevents the trigger from being
  pulled, or
  otherwise prevents the firearm from being discharged.
• Sear
  Pivoting part of the action of a firearm connecting the trigger to the
  hammer and holding it in place until released by the trigger.
• Selective Fire
  Feature of a firearm that allows firing either on full-automatic, or
  semi-automatic mode, usually with the use of a switch or
  lever.
• Semi-Automatic
  A firearm that automatically extracts and ejects spent cartridges upon
  firing, then
  re-chambers a new one to be fired, and can repeat this action, one
  trigger
  pull at a time, until the magazine or clip is empty.  This
  action takes place very rapidly.
• Shot
  Small metal balls, grapeshot or buckshot, used in shotgun
  cartridges.  Shot comes in different sizes.
• Shotgun
  Firearm with a smoothbore barrel, used to fire buckhot or shot.
  Modern shotguns use brass-based plastic cartridges filled
  with shot.
• Single Action
  Firearm that requires the hammer to be manually cocked before pulling
  the trigger. On a single-action semi-automatic, you only need to cock
  the hammer before firing it for the first round, until it’s reloaded.
• Sight
  Blade or protusion with a notch in it, usually on both the rear of the
  firearm and on the front, above the muzzle, to allow the shooter to
  line them up with the target.  There are many different types
  of sights.
• Silencer or Silenced
  Device attached to the muzzle of a firearm to muffle or reduce the
  sound of firing.
• Slide
  On firearms (usually semi-automatic pistols) the top part of the action
  (usually the entire top of the pistol) that ejects and loads the
  chamber by pulling it back, sliding it back
  along the frame.
• Spitzer
  A bullet with a pointed nose
• Stock
  The long part of a firearm (usually a rifle or musket) held by the
  shooter, or braced against the shooter’s hip or shoulder, to stabilize
  during firing.  Can be wood, polymer, metal etc.
• Submachine Gun
  Automatic firearm that uses pistol ammunition.  Usually a
  smaller version of a full-size machine gun.  Used for
  close-range firing.
• Take Down
  Button, lever or other device that allows for quick disassembly of a
  firearm for cleaning, oiling and maintenance, transportation etc.
• Tang
  Protusions on the frame or receiver that connect it to the stock or the
  grip.
• Top Strap
  Top part of the frame on a revolver.
• Wildcat Cartridge
  Non-standard cartridge.

The Glossary Above is Proprietary and is Protected by United States Copyright Laws. Copyright © 2009 4G Company

I have added an expanded version of this glossary at Gun Classics.com.