Glossary of Firearms Terms



Abbreviation for Automatic Colt Pistol.


A firearm's working mechanism (typically the receiver or frame and breech bolt) that facilitates its firing and loading/unloading. There are a variety of actions from single to automatic.

action shooting

A competitive event where participants draw holstered pistols and fire at various shaped, small targets. The winner is the most accurate shooter or fastest shooter.


Refers to any gun that fires projectiles (BBs, pellets) by C02 or compressed air.


Abbreviated form of ammunition.


A complete assembly consisting of a case, a charge (gunpowder) and a projectile. Also known as fixed ammunition.


Refers to any firearm, made before 1899, that is not designed to fire fixed ammunition or for which ammunition is unavailable.

armor-piercing ammunition

The U.S. government defines it as projectiles that are used in handguns and which consist (entirely or primarily) of beryllium copper, brass, bronze, depleted uranium, iron, steel or tungsten alloys.


A government facility that makes, repairs, and stores ammunition and firearms.


Typically refers to firearms with bore diameters of three or more inches. Generally, they fire explosive projectiles and must be operated by a crew.

assault rifle

A selective-fire rifle designed to rapidly fire intermediate power cartridges. This type of firearm originated in early 1940s Germany. Their "storm rifle" was made to spray bullets to maximize the weapon's ability to wound and kill during combat.

assault weapon

Technically, any weapon used in an assault, but usually refers to firearms that are compatible for efficient attacks (see weapon).

auto(matic) loading

See semiautomatic.


Firearm that continuously feeds cartridges, fires their bullets and ejects their empty cases.

automatic pistol

Popular term that is a misnomer (see semiautomatic pistol).



The part of a pistol that is exposed at the rear of the grip.


Typically refers to a cylinder-shaped bullet with either a rounded or pointed nose and is typically used with muzzle-loaded firearms.


The study of projectile motion and effects.


The rifled or smooth tube that a projectile travels after it has been fired.

barrel band

A fixed or adjustable band that holds a gun's barrel and stock together.

barrel liner

A liner made of special material that is inserted into a bore to either protect the bore, correct bore erosion, or to alter the bore so that it can fire smaller caliber ammo.

barrel locks

Devices inserted into a firearm's barrel or barrel and chamber to prevent discharge.

bayonet lug

A mounting on a firearm for attaching a bayonet or accessory.

beavertail forend

A wide-styled forend.

benchrest (shooting)

A competition where participants, firing from a fixed shooting position, attempt to place consecutive shots into the smallest possible grouping on a paper target. Typically, it involves groups of at least 10 shots and at different target distances.

bird shot

Refers to shotgun projectiles that have a diameter less than 24 inches.


The earliest form of firearm propellant. Except for its use in antique guns, it has been replaced by higher pressure, smokeless powder.

blank cartridge

A cartridge containing a charge, but NO projectile, used for starter's guns or for special uses such as in movies or stage productions, etc.

blind box magazine

A magazine that is inserted into a firearm handle and has a permanent closed bottom.


A gun's blue or black metal finish that is the result of an acid bath.


A bullet with a tapered end to improve its long-range efficiency.

body armor

Vest type jacket worn by law enforcement or military personnel. It is usually made of light-weight, bullet-resistive material such as Kevlar.


A firearm with an assembly that requires a user to manually lock a cartridge into firing position in its barrel or chamber.


The interior of a firearm's barrel excluding the chamber.

box magazine

An ammunition holder where the cartridges are vertically stacked.


A slang term for a spent case. It's used because a case is most commonly made out of brass.


The rear part of a gun's bore.


A movable piece of metal used to open and close a gun's breech.

buck shot

Refers to shotgun projectiles that have a diameter 24 inches or greater.

buckhorn sight

An open, metallic rear sight with sides that curl similarly to a buck's horns.

bull barrel

A heavier, thicker than normal barrel with little or no taper.


The projectile expelled from a gun that is distinct from a cartridge. Bullets come in a variety of types and are usually composed of lead or lead that is shielded with a harder metal.

bulletproof jacket or vest

A misnomer (see body armor).


Describes the bottom part of a pistol grip and the rear or shoulder portion of a rifle or shotgun stock.

butt plate

A covering that protects the butt of a firearm. The cover may be metal, plastic, rubber or some other material.

butt stock

Similar to butt, but more accurately applied to separate attachment at the end of a gun stock. It is designed to absorb recoil and is contoured for comfortable placement upon the shoulder.



The diameter of a projectile for a rifled firearm or the interior diameter of a rifled barrel. In the U.S., the diameter is expressed in hundredths of an inch.


This name applies to any short-barreled rifle (designed for easier use and concealment).


A single, complete round of ammunition consisting of a case, charge (propellant) and projectile (bullet).

case, casing

The material that surrounds and holds the charge and/or projectile and which is typically made of brass.

caseless ammunition

Ammo that includes a propellant charge in its base rather than a separate case.


A cartridge with a primer placed at the center of its casing's base.


The area of a firearm that holds a cartridge immediately prior to its being fired.

charcoal color case-hardening

A method of hardening gun metal by subjecting it to high heat and plunging it into cold water.

charging handle

A handle that cycles a semi or fully automatic firearm without discharging.


The diamond-shaped tool patterns that are cut into firearm grips.

cheek piece

A raised portion on the side of the gun's stock where a user rests his or her cheek while operating a gun.


A constriction at or near a shotgun muzzle. It is designed to control shot dispersion.


Popularly refers to a container that holds a group of cartridges, which may either be transferred or inserted into a firearm.


The hammerlike device on early firearms that set the weapon into "firing" position.

cocking (a gun)

Pulling back a gun's hammer into position for firing it.

cocking handle

See charging handle.


The portion of the stock where a shooter rests his or her cheek.

combination gun

Typically refers to a shotgun-style base, supporting both a rifle and a shotgun barrel, and capable of using several different calibers of ammo.


See muzzle brake.

cop-killer bullet

An inflammatory phrase typically used to refer to ammunition capable of piercing body armor (bulletproof jackets).


A U-shaped yoke that supports and facilitates the operation of a cylinder.

cross hairs

The sighting lines in a telescopic sight.


The process of rounding and countersinking a barrel muzzle.


A drum-shaped component of a revolver that houses its ammunition.



Decorating one metal by inlaying or attaching another metal.

Damascus barrel

A barrel made by welding thin strips of metal that have been twisted around a metal rod (called a mandrel).


A very short-barreled (one or two shot) pocket pistol named after its inventor, Henry Derringer.


To ignite (initiate) an explosive device.


To fire a weapon.


Travel pattern of bullets fired from a single source.


A firearm that is fired either by manually cocking the weapon and then pulling the trigger or by using trigger action to both cock and fire the weapon.

double-barreled shotgun

A shot gun with two separate barrels, allowing for two discharges before reloading.


A German term, referring to a gun with three barrels.

drum magazine

Refers to an ammunition holder where cartridges are stored in a circular fashion.

dry firing

Discharging an unloaded firearm in order to become familiar with its operation.


A popular term for a cartridge that fails to fire after its primer is struck by the firearm's firing pin (see hangfire).

dum-dum bullet

A lead-core, shielded bullet with an open nose that was developed by the British in the late 19th Century. It was outlawed by the 1899 Hague Convention.



A mechanism that throws cases free of a firearm.

English stock

A straight stock with a slender grip.


(NRA Condition Standard) All original parts; over 80% original finish; sharp lettering, numeral and design on metal and wood; unmarred wood; fine bore.

expanding bullet

Any bullet that is designed to expand upon striking. This action increases the bullet's stopping power (and lethality).

expert marksman

A highly skilled shooter, capable of hitting any target falling within weapon range.

exploding bullet

A bullet with an explosive component that explodes under striking. (Ironically, this feature severely reduces its ability to penetrate a target.)


A device that pulls spent cases out of a chamber.

extrinsic safety

An external component that is attached to a gun to avoid unintended discharge, such as a separate trigger lock.


Factory New

(NRA Condition Standard) All original parts; 100% original finish; in perfect condition in every respect, inside and out.


(NRA Condition Standard) Some major parts replaced; minor replacement parts may be required; metal rusted, may be lightly pitted all over, vigorously cleaned or reblued; rounded edges of metal and wood; principal lettering, numerals and design on metal partly obliterated; wood scratched, bruised, cracked or repaired where broken; in fair working order or can be easily repaired and placed in working order.


To move a live cartridge from a firearm's magazine to its chamber.

field load

A shotshell load designed for hunting small bird and game.


(NRA Condition Standard) All original parts; over 30% original finish; sharp lettering and numerals on metal and wood, minor marring on wood; good bore.


Technically, any pistol, rifle or shotgun that uses gunpowder to launch projectiles.


A generic reference to how heavily or seriously armed a party is.

firing pin

The breech component that strikes the primer, igniting the cartridge.

fit and finish

Refers to a firearm's overall workmanship.

fixed ammunition

See ammunition.


The light emitted from a weapon's muzzle when it is discharged.

flash hider/flash suppressor

An accessory that is attached to a muzzle. It is designed to minimize any visible muzzle flash during discharge.


An antique gun that has a firing mechanism consisting of flint striking steel to create sparks, which ignites a primer.

floor plate

The removable bottom plate of a cartridge magazine.

floating barrel

A barrel bedded to avoid contact with a gun's stock.


See full metal jacket.

forcing cone

The tapered front section of a revolver or shotgun chamber that reduces in size to match the barrel's bore (diameter).


The front portion of a rifle or shotgun stock.


See receiver.

frangible bullet

A projectile designed to minimize ricochets by disintegrating when a hard surface is struck.

free rifle

A rifle, having to weigh less than 17.6 pounds, that is designed for international-type target shooting.

front strap

The forward facing portion of a pistol or revolver that is joined with the trigger guard.

full metal jacket

A bullet that is fully encased with a layer of hard metal jacket, which maximizes its ability to penetrate a target.



An automatic or semiautomatic firearm that uses propellant gases to operate its case ejections.


Refers to a shotgun barrel's bore size.

Geneva Convention(s)

A set of international agreements regarding the behavior of warring nations. It is frequently noted for its ban on the use of ammunition designed to expand upon impact.

ghost ring sight

A sight with a large opening and a thin rim that is positioned on the rear of a rifle or a shotgun. It is used in conjunction with a front-mounted sight and results in the ability to quickly find a target.


(NRA Condition Standard) Some minor replacement parts; metal smoothly rusted or slightly pitted in places, cleaned or reblued (metal re-colored); principal lettering, numerals and design on metal legible; wood refinished; scratched, bruised, or minor cracks repaired; in good working order.

grip safety

A locking device located on the grip, which prevents a discharge unless depressed.


See rifling.


In the U.S., term may be applied to airguns, cannons, pistols, rifles and shotguns.

gun control

Typically refers to either existing or proposed laws involving firearm sales and ownership.


The firearm mechanism responsible for exploding the primer (charge).


The art/practice of building and operating large bore guns.

gun nut

A pejorative label for a gun enthusiast.


Any powdered substance that can be ignited and is suited for propelling projectiles.

gun safe

See lock box.


A person skilled in making and repairing guns.



The firearm component that causes the firing pin to ignite a cartridge primer.

hammer block

A safety device that separates the hammer from the firing pin until discharged.


A firearm with a frame design that conceals its firing pin and hammer.


See pistol.


A cartridge that has a delayed discharge due either to defective primer or a defective blow from a firing pin.


See base.

high-capacity magazine

An informal reference to a magazine holding a high number of cartridges.

hinged frame action

A firearm design where the action may be opened to pivot down, sideways or up to allow for loading and unloading.

hollow-point bullet

A bullet with a concave nose that maximizes its ability to expand after it penetrates a target.


A fairly recently coined term for persons with an irrational fear of weapons. Apparently pejorative, it comes from the Greek words for tool or weapon and fear.


Abbreviation for a hollow-point bullet.


intrinsic safety device

Any permanently installed firearm component that is designed to minimize the chance of an unintended discharge.

iron sights

A nontelescopic firearm sight.



A layer of material, metal or synthetic (typically lead) that encloses the core of a bullet.


Abbreviation for a (jacketed) hollow-point bullet.


Abbreviation for a jacketed soft point bullet.



The elongated hole caused when an unstable projectile strikes a target sideways.


laminated stock

A warp-resistant stock that is made of layers of wood that have been glued together under pressure.

land and groove impression

The rifling marks left on a discharged bullet.


See rifling.


A gun mechanism that is operated (loaded, fired, unloaded) by a lever, typically located below the receiver.


A firearm with a cartridge in its firing chamber.

loading gate

A hinged or spring-loaded cover that, when opened, allows a firearm to be loaded.

loading port

A receiver opening that facilitates a cartridge.


Typically refers to securing the bolt of a firearm before firing it.

lock box

A heavy, metal storage box with either a key or combination lock that is used for a pistol, ammunition and accessories storage.


machine gun

A rifled firearm capable of automatically feeding, firing and ejecting high-powered cartridges. Typically only military ownership and use is permitted.

machine pistol

See submachine gun.


Refers to either a permanent or detachable, spring-loaded container for cartridges. It is often considered the same as a clip. One distinction is that, externally, a magazine appears to complete the firearm's form, while a clip is an ammunition insert (or transfer device) that does not affect external appearance.

magazine floorplate

The bottom of a fixed magazine.

magazine follower

A spring-actuated device to push cartridges in a magazine to the feeding position.

magazine release

A device that retains or releases a detachable magazine in a firearm.

magazine safety

A device that prevents the full insertion of a magazine into a pistol, preventing it from being fired until it is disengaged.

magazine well

The opening in a firearm that receives the detachable magazine.


Refers to a gun designed to fire heavy-load metal cartridges or shells.


A strong spring, a.k.a an energy storage device, that operates the striker or hammer of a firearm.

Mannlicher stock

A slender forend that extends to the muzzle.


A treated cord (cotton or hemp) used for ignition in matchlock firearms.


An early firearm with a firing mechanism that held a smoldering, treated cord (match), which would burn until it reached a barrel opening (touch hole), explode the powder, and discharge a bullet.

metallic sights

See iron sights.

micrometer sight

A sight that is finely adjustable.

Monte Carlo stock

A stock with an elevated comb that is typically used with rifles equipped with telescopic sights.

military firearm

An informal term, generally implying a pistol with accessories that is suited for military rather than civilian use.


When cartridge fails to fire due to it or a firearm being defective.


A gun with more than one barrel (example, double-barreled shotgun or derringer).

mushroomed bullet

Describes a bullet's nose which has expanded after striking a target.


A smoothbore shoulder-held gun with a long barrel and elongated stock.


A barrel's open end that is a projectile's exit.

muzzle brake

A muzzle with an accessory or a modification that acts to control gas expansion which, in turn, reduces the amount of gun recoil.


The earliest forerunner of modern firearms. Such guns require powder and projectiles to be separately loaded through either the muzzle or, with revolvers, through cylinder chambers.


National Firearms Act of 1934

The federal act that regulates firearm ownership and sales and registration of certain classes of firearms.

negligent discharge

A term that is used to refer to unintended discharge of a firearm that causes bodily injury, property damage, etc. Gun advocates and proponents debate whether it should be synonymous with accidental discharge.

NRA (National Rifle Association)

This organization is an advocate of the public's right to own guns, provides training related to safe gun use, and sponsors firearm competitions on a national basis.



The curved nose of a missile, rocket or projectile.

open sight

A commonly used sight that is located at the rear of pistols, rifles and shotguns, and has an open notch at its top.

operating handle

See charging handle.

optical sight

Generic reference for laser and telescopic sights.

out of battery

Describes a breeching mechanism that is properly aligned for firing.


See spray.


A two-barrel gun in which the barrels are vertically stacked.



A small, side-mounted container found in early firearms that held priming powder.


A gray or green rust-resistant, matted finish used on military guns.

partition bullet

A two-chambered, jacketed bullet. The front portion expands on impact and the rear piece remains intact to ensure penetration.


Refers either to cloth used to clean a gun's bore or a piece of leather or cloth that is wrapped around a bullet (round ball) before a ram rod is used to load it into a muzzle-loaded gun.

patch box

A covered compartment in the butt stock of a muzzle-loading rifle that stores, primarily, patches.


Small round projectiles loaded in cartridge shells and/or the skirted projectiles used in pellet guns.

pellet gun

A rifle or pistol that fires pellets using compressed air or CO2.


Early form of a repeating pistol consisting of several barrels bored in a circle in a metal cylinder.

percussion cap

A small metal explosive-filled cup that is placed over the nipple of a percussion firearm.

percussion lock

An early firearm, such as a flintlock, that is operated via a gunlock that strikes a percussion cap.

personalized gun

A pistol that has been specially customized so that it may only be fired by an authorized user. A magnetic or electronic system is used so that only the authorized person can release the firing mechanism.


Any type of gun including a revolver that may be readily held and fired in one hand.

pistol grip

The protrusion on the handgun, or on the buttstock or front portion of a shoulder-operated gun, that allows the weapon to be comfortably held by a hand.


Describes the very common practice of firing at various inanimate targets.


(NRA Condition Standard) Major and minor parts replaced; major replacement parts required and extensive restoration needed; metal deeply pitted; principal lettering, numerals and design obliterated; wood badly scratched, bruised, cracked or broken; mechanically inoperative; generally undesired as a collector's firearm.

pope rib

A ribbed barrel designed to facilitate a forward-mounted scope.

practical shooting

A sporting activity involving the simulation of the environment in which small arms are used.


The part of a cartridge that is ignited to propel a bullet.

proof mark

A stamp applied to a firearm to indicate its passage of a proof test.

proof test

Testing a firearm's barrel and action strength by firing overloaded ammunition.


Refers to the source that propels a projectile such as ignited powder charge in a firearm or, in pellet guns, compressed air or CO2.

pump action

A mechanism attached to the front end of a rifle or shotgun stock. When slid forward it ejects a spent case and when slid back, a new round of ammo is loaded.

pumpkin balls

Larger bore projectiles that are fired by shotguns.


Quaker gun

Refers to a fake, usually wooden gun, used as a prop.



A wood or metal rod for loading a wad and bullet into the barrel of a muzzleloader.


See action.

receiver ring

The part of the receiver that is threaded to allow attachment of a barrel.


The reactive, often violent, force that occurs after a firearm has been fired.


Refers to a firearm (usually a rifle) designed or modified to fire with minimum recoil (kickback action).

recoil shield

Refers to metal extensions on the frame of a gun that prevents cartridges from sliding off of a cylinder as well as protect exposed cartridge primers.

recoil spring

A spring that repositions a gun slide back into firing alignment (battery).


A previously used cartridge that has been reassembled with a new charge and projectile.

repeating firearm

A firearm capable of being fired repeatedly without manual effort by its user.


Typically, a pistol with a multichambered cylinder that rotates to lineup each chamber with a single barrel and firing pin.


A raised surface that is located along the top of a gun barrel and is used as a sight.


A projectile that's diverted in another direction after initial impact.


A shoulder gun having a barrel with a rifled bore.

rifled slug

A cylinder-shaped projectile designed to be fired by a shotgun.


Refers to cutting spiral grooves into a gun's bore. This results in a projectile being spun when shot, creating a more accurate (stable) flight.


A cartridge with a rim that contains primer.

riot gun

A term for a short-barreled repeating shotgun.


See cartridge.



A smaller caliber cartridge encased in a larger bore carrier. This modified cartridge allows a larger caliber firearm to shoot smaller caliber ammunition.


A firearm accessory designed to prevent discharge by locking the firing mechanism.

Saturday night special

A pejorative term that originated as a catchall reference to very inexpensive handguns that were used in weekend crimes and violent altercations.

sawed off

Generally refers to a short-barreled rifle or shotgun; implying a firearm that's been illegally altered for concealment.

sawed-off rifle

Refers to a rifle with a barrel length of less than 16 inches.

sawed-off shotgun

Refers to a shotgun with a barrel length of less than 18 inches.

Schnabel forend

A beaklike curved or carved shape at the forend.


See telescopic sight.


The part of a firearm that keeps a hammer cocked until the trigger is pulled.


A firearm that can be fired automatically, semiautomatically or, sometimes, in rapid bursts, at the user's option.


Depending upon the firearm, it is a device that allows the user to choose among barrels or among types and rate of firing actions.


A firearm that, with each pull of a trigger, fires, ejects and reloads a single cartridge.

semi-pistol grip

A smaller version of a pistol grip.


A bullet with cone-shaped nose and a sharp edge meant for carving full holes in targets.


The material that surrounds and holds the charge and/or projectile and which is typically made of paper or plastic with a metal head. Also the exploding projectiles fired by cannons.


See pellets.

shot dispersion

See dispersion.


A shoulder gun with smooth-bored barrel(s) that is designed to fire shells filled with multiple projectiles which vary in size. The projectiles spray out when shot, resulting in a weapon that is effective at close range.


See shell.

side-by-side shotgun

See double-barreled shotgun.

short action

A rifle designed to use shorter cartridges.

side plates

Ornamental metal plates that simulate a side lock gun.


A misnomer for an illegal firearm accessory that, when attached to a muzzle, substantially reduces the noise made by the discharge.

silhouette shooting

A competition where participants fire at (usually animal-shaped) metal targets that are placed at different distances. May involve either pistols or rifles.


See single-shot.


A gun mechanism that requires ammunition to be manually loaded in the gun's chamber before each discharge.


A competition where participants, armed with shotguns, test their ability to hit fragile clay targets that are launched into the air at different angles, planes and heights.


See barrel liner.

slide action

See pump action.


See rifled slug.

small arms

Firearms designed for use by an individual or individuals.

smokeless powder

See gunpowder.

small bore

Another name for a .22 caliber firearm.


The interior of a barrel without rifling.


Typically refers to a revolver with an unusually short barrel.

soft point

A bullet with a metal jacket but an exposed nose that allows it to expand upon hitting a target.


Abbreviation for a soft point bullet.

spitzer bullet

A sharp-pointed, long ogived bullet.

sporting clays

A shotgun firing competition that simulates field conditions. It is a combination of skeet and trap shooting.

spray (aka spray and pray)

Attempting to hit a target by rapidly firing a large amount of ammunition.

staggered column magazine

A magazine consisting of two staggered columns of cartridges that increases a magazine's capacity but not its length.


The firearm component to which a barreled action is attached. It allows a firearm to be held and used.

stripper clip

See clip.

submachine gun

A firearm that automatically fires pistol ammunition and that is designed for close combat.


See firing pin.


Abbreviation for semi-wadcutter.



A gun which can be easily taken apart for carrying or shipping.


The portion of a receiver that extends and fits into a stock.


Refers to metal bullets that are coated with this trade name synthetic or similar materials. The coating is merely to protect a firearm's rifling rather than affecting the efficiency of the bullets.

telescopic sight

A small arms sight that uses optical lenses to provide a magnified view.


The bottom of a rifle or shotgun butt.

top strap

The exposed upper part of a revolver or pistol frame.


The curved, aerial path traveled by a projectile.


An event where shotgun-armed participants fire at fragile targets that are launched away from them at different angles and heights.

trap stock

A heavier, elongated shotgun stock designed for trap shooting.


The manually operated firearm component that causes its discharge.

trigger locks

Devices such as blocks or covers that deny access to a pistol's trigger.


A measurement of a barrel's rifling (in inches) referring to the length of barrel it takes before the rifle spiral forms a complete turn.

tube or tubular magazine

A tube-shaped magazine (ammunition holder) where cartridges are stored end to end.


No Entries


vertical pistol grip

A larger, more pronounced version of a regular pistol grip.

Very Good

(NRA Condition Standard) All original parts; none to 30% original finish; original metal surfaces smooth with all edges sharp; clear lettering and numerals on metal; wood slightly scratched or bruised; bore disregarded for collectors firearms.



A flat-headed bullet designed to "punch" out holes in paper targets, making it easier to score target efficiency.


Abbreviation for wadcutter


Refers to an object's use, rather than nature; so a weapon is any item that is used in offensive or defensive combat.

weaver stance

A special shooting style where pistols are gripped with both hands to minimize the effects of recoil, increasing accuracy.

wheel lock

An early firearm mechanism where a spring-actuated wheel with serrated edges is spun against a piece of iron pyrite. The resultant sparks then ignites the charge held in the firearm's pan.

wildcat cartridges

Cartridges that are made and used by private parties.


No Entries


youth dimensions

A firearm that is lighter or smaller to accommodate its use by women or youth.



The farthest distance at which a projectile accurately hits its target or the practice of properly aligning a firearm's sights.