Firearms Glossary

For the most part, this glossary is as provided within the Canadian Firearms Safety Course and the Canadian Restricted Firearms Safety Course. Terms with any legal significance (i.e. “prohibited ammunition”) have been removed. For information regarding firearm laws in Canada, please visit the RCMP’s Canadian Firearms Program. Some additions and revisions will be made.


A Top

The part of a firearm that loads, fires, extracts and ejects ammunition.

Action release
The part of a firearm that unlatches or opens the action to give access to the chamber.

A firearm that uses compressed air or carbon dioxide to propel a projectile.

Aperture sight
A rear sight with a hole for viewing the target. Also known as a peep sight.

An action that fires cartridges in rapid succession during one sustained pressure of the trigger.

B  Top

a) A lead projectile fired by black powder firearms.
b) Full metal jacket ammunition.

The study of projectiles in flight and what affects them. This means the barrel, in flight and within the target, including trajectory, force, impact and penetration.

The metal tube of a firearm. The bullet, shot or projectile accelerates through it when the firearm is fired.

Barrel length
The distance from the muzzle to the chamber, including the chamber itself. This measurement does not include accessories or barrel extensions like flash suppressors or muzzle brakes. The barrel length of a revolver is the distance from the muzzle to the breech end immediately in front of the cylinder.

BB gun
A type of air gun designed to use spherical steel BB pellets.

Big bore
A rifle shooting term which refers to centre-fire firearms or ammunition.

Black powder
A finely-ground powder, mainly used in muzzle-loaders and antique cartridge firearms. The basic ingredients are salt-petre (potassium nitrate), charcoal (carbon) and sulphur.

Blueing or Bluing
An oxidation (rust) process applied to firearm metal parts. Controlled by applying oil which mixes with the nitrates used in the process. The oil prevents further rusting by sealing the metal. This gives the metal a blue/black colour which resulted in the name “bluing”.

Boat tail
The tapered rear end of some bullets, used to increase ballistic efficiency at long range.

A steel rod-like assembly which moves back and forth in an action, sealing the cartridge in the chamber during firing.

Bolt action
For registration purposes, a repeating firearm that has a magazine and in which the breech bolt or closure device operates in line with the bore; manually operated by a permanent projection or handle attached to the bolt or closure device.

Bolt face
The forward end of the bolt which supports the base of the cartridge.

The inside of the barrel of a firearm excluding the chamber. The channel through which the bullet or other projectile is fired from the gun.

Bore diameter
The measurement from one side of the bore to the other. Also, see rifling and calibre.

The rear end of the barrel into which the ammunition is loaded. See chamber.

The part in the breech mechanism that locks the action against the firing of the cartridge.

Breech loader
A firearm loaded through the breech.

Large lead pellets used in shotgun shells.

A projectile designed to be fired from a rifled barrel.

The rear end of a rifle or shotgun (the portion that rests against the shoulder.) In a handgun, the bottom part of the grip.

Butt plate
Plate put on the butt end of a stock. May be used for cosmetic reasons, for cushioning, or for aiding in the duplication of rifle position.

Butt stock
In long guns, the part of the stock which extends from the receiver to the butt.

C  Top

A measurement in metric or imperial units to describe the inside diameter of the barrel of a rifled firearm. Calibre is also used to describe the diameter of a projectile in a cartridge.

See percussion cap.

A light short-barrelled rifle.

A complete unit of ammunition consisting of a case, primer, powder and a projectile. Modern cartridges are generally classified into two categories: centre-fire and rim-fire. Also, see shell.

Cartridge magazine
A device or container from which ammunition may be fed into the firing chamber of a firearm. The Cartridge Magazine Control Regulations set out the limit for the number of cartridges permitted for different types of magazines. The two common types are box-type magazine and tubular magazine.

Also called casing. The container of a cartridge. It is usually of brass or other metal when used for rifles and handguns. When used for shotguns, it is usually of paper or plastic with a metal head, and is more often called a hull.

a) As a verb – the command to stop shooting, unload firearms and step behind the cease-fire line.
b) As a noun – time or period of range inactivity while targets are changed or other activities are conducted.

A cartridge with its primer located in the centre of the base of the case.

The term used to describe the dangerous result of not using grease over the balls used in a black powder revolver. When the primary cylinder is fired, lack of grease on the other cylinders may cause them to discharge before they are lined up with the barrel.

a) The portion at the breech end of the barrel. The cartridge is placed in the chamber ready for firing. A revolver is multi-chambered.
b) To place a cartridge in the barrel.

a) The amount, by weight, of the powder in a cartridge.
b) In the case of black powder, the amount, by volume, of the powder used.
c) To fill a magazine with cartridges.

Cheek Piece
A lateral projection from the comb of the stock. Provides additional support and contact to the cheek when the rifle is shouldered in the firing position.

Chief Firearms Officer
The person in authority in a province or territory responsible for licences, authorizations to transport, authorizations to carry and other functions related to the administration of the Firearms Act and its Regulations.

Narrowing at the muzzle end of a shotgun barrel which determines the shot pattern.

Cleaning kit
A set of specialized accessories used to clean and maintain a firearm.

An incorrect term used to describe a magazine.

CO2 Powered
Carbon dioxide. A propellant in which the energy source is obtained from compressed carbon dioxide gas.

To set the action into position for firing. On some firearms, the action has an intermediate position called half cock.

On muzzle-loading firearms, the cock holds the flint or match.

The burning of black powder residue with much heat and little smoke.

The upper edge of a rifle or shotgun stock where the holder’s cheek rests.

Conical bullet
A cylindrical shaped bullet with a cone shaped tip.

The part of a bullet that is covered by a jacket, i.e. the centre of a bullet.

The gradual eating away of the metal parts of a firearm caused by rust or other chemical reactions.

The portion of a cartridge or shell case that is bent inward to hold the bullet or shot in place.

Cross-bolt safety
A device that blocks the firing mechanism of a firearm.

The sighting lines in a telescopic sight.

The part of a revolver that rotates and in which chambers are bored to hold cartridges. It combines the functions of magazine, feed system and firing chamber.

Cylinder bore
A shotgun barrel having the same diameter throughout, i.e. without choke. It is used to fire solid slugs.

D  Top

Dangerous range
The maximum distance at which a projectile will travel. Also, see range.

Dominant eye
See master eye.

Double action
An action that cocks and fires with a complete pull of the trigger.

Double action only
An action which cannot fire in a single action mode.

Double-action revolver
A revolver that both cocks and fires with a complete pull of the trigger.

A firearm with two barrels, either side-by-side or one over the other.

Down range
The direction from the shooting position towards the target on a range. Also, see range.

Dry firing
Firing of an unloaded firearm to practice handling and shooting techniques. This can damage some types of actions, particularly rim-fire.

Dummy ammunition
Inactive ammunition used for practising handling of firearms. It has no primers or propellants. Also, see live ammunition.

E  Top

Effective range
The maximum distance for a shooter at which he or she can confidently hit the target. Also refers to the useful range of the projectile(s). Also, see range.

Vertical adjustment of the rear sight to change the projectile’s point of impact either up or down.

The mechanism which expels the cartridge or case from the firearm.

The removal of a cartridge or case from the chamber of a firearm.

F  Top

The action of moving a fresh cartridge into the chamber.

Feeding path
The path a cartridge follows within an action.

Field stripping
Taking apart a firearm for regular maintenance and cleaning.

Firing pin
The part of the breech mechanism which strikes the primer of the cartridge.

Flash suppressor
Muzzle attachment designed to cool emergent gases and prevent or reduce muzzle flash.

Flat-nosed bullet
A bullet with a flattened front end. It is used mainly in cartridges designed for rifles with tubular magazines.

A small dart stabilized by fins. It is encased in a discarding sabot (case) and loaded into a shotgun shell. Usually, one shell will contain a number of flechettes. This type of ammunition is prohibited.

The gunlock of early firearms in which flint is struck against steel. This causes sparks to ignite the powder charge.

Floor plate
The metal plate at the bottom of some cartridge magazines. (The floor plate is usually hinged at the front and held by a release spring located just ahead of the trigger guard.)

Staying in the same position after squeezing the trigger or continuing the swing in firing at a moving target. This helps to shoot accurately.

The part of a magazine between the spring and the ammunition. You must be able to see or feel the follower to know the magazine is empty. Also, see magazine follower.

Forcing cone
In smooth bore and revolver barrels, a cone which joins the chamber to the bore. It assists the passage of the projectile(s) into the bore. Also called a throat.

The forward part of a one or two piece stock. It is sometimes called a slide on pump action firearms.

The front portion of a one-piece or two-piece shoulder arm stock. Located under the barrel, the fore-stock serves as a hand-hold. It is also called a fore-end.

Feet per second. A unit of measurement to express how fast a projectile is travelling (velocity.)

The metal arm of a flint-lock mechanism. The flint strikes the frizzen to create sparks in the flash pan. It is also called a battery.

Full cock
The position of the hammer or striker when the firearm is ready to fire.

Full metal jacket
A bullet with a jacket, usually of harder metal, encasing the core. It is also called a hard-point bullet. Used in ball ammunition

G  Top

The measurement of the diameter of a shotgun bore.

A unit of weight (7,000 grains equal one pound) commonly used to measure the weight of ammunition components.

Black powder and its substitutes are measured in grains by volume. Modern powders are measured by weight.

The small portion of the stock gripped by the trigger hand.

See rifling.

H  Top

Half cock
A safety feature on some firearms. When the hammer is pulled back half-way, it cannot be fired by squeezing the trigger.

The part of the action that drives the firing pin forward.

A malfunction causing a delay in firing a cartridge after the firing pin has struck the primer.

High power
A term applied to the first smokeless powder cartridges with velocities of approximately 609.6 metres per second (2,000 feet per second).

High power rifle
Generally, a firearm that uses centre-fire ammunition.

The action of keeping the sights on the target while squeezing the trigger.

Hollow point
A bullet with a hollow at the tip (nose) that makes it expand more on impact.

The outer covering or casing of a shotgun shell.

I  Top

J  Top

The outer covering over the inner metal core of a bullet.

K  Top

See recoil.

L  Top

See rifling.

Particles from shot or bullets that stick to the metal surface of the bore. This is due to heat or friction.

Lever action
a) An action operated by a lever located underneath it. (A secondary purpose of the lever is to serve as a trigger guard).
b) For registration purposes, a repeating firearm that has a magazine and a breech mechanism cycled by an external lever, usually below the receiver or frame.

Line of sight
An imaginary straight line from the shooter’s eye to the target; usually through the sights.

Live ammunition
Ammunition containing primers and propellants capable of firing bullets or other projectiles.

To prepare a firearm for firing by inserting ammunition into it.

Loading gate
The hinged cover over the opening through which cartridges are inserted into the magazine or chamber on a revolver.

Loading port
The opening through which cartridges are inserted into the magazine or chamber on a revolver.

The firing mechanism of a muzzle-loader.

In firearms that are loaded through the breech, the lock is both the firing mechanism and breech-sealing assembly.

Long gun
Generic term used to describe rifles and shotguns.

M  Top

See cartridge magazine.

Magazine cut off
Disengages magazine feed from firearm.

Magazine follower
Spring-loaded platform in a magazine. It pushes cartridges or shells to the feeding position.

When checking that a firearm is completely unloaded, the magazine follower should be clearly in view. This is especially important with tubular magazines.

Magazine release
A button or switch which allows for the removal of a magazine from the firearm.

a) A cartridge or shell with a larger capacity or with a higher velocity than average (e.g. 3.5 inch Magnum shot shell, .300 Winchester Magnum rifle, .44 Remington Magnum handgun). Firearms that use magnum ammunition may also be called magnum.
b) A marketing term used by manufacturers which may or may not indicate greater power or range.

A strong spring which activates the striker or hammer of a firearm.

The failure of a firearm to work properly. This can be caused by a jam or stoppage, or a mechanical or structural failure.

Master eye
The stronger eye; the eye through which a person usually views an object as when sighting a firearm.

A long cord soaked in saltpetre, which burns slowly. Used to ignite powder in early firearms.

A firearm action which uses a serpentine or S-shaped piece of metal to hold a smouldering match. The burning match contacts the priming powder in the pan to ignite the charge.

Metallic cartridge
A cartridge with a metallic case. In contrast, early cartridge cases were made of linen, paper, etc.

The point in the trajectory halfway between the muzzle and the target.

Mini-ball or Minie ball
A cylindrical shaped bullet used in muzzle-loaders. It has a pointed tip and a hollow base which spreads as it is fired.

The failure of a cartridge to fire after the firing pin has struck the primer. Do not confuse with hangfire, which is a delay in firing.

Monte Carlo stock
A stock with a raised comb. Provides elevated eye alignment when using a telescopic sight.

The shape many soft-point bullets become when they expand upon impact.

An early smoothbore shoulder firearm.

The opening at the end of the barrel from which the projectile exits.

Muzzle brake
A device attached to the muzzle which softens the recoil of the firearm. Also known as a compensator.

A firearm that is loaded through the muzzle.

N  Top

O  Top

An object which is not transparent.

Open sight
A type of firearm sight, usually with a “V” or “U” notch in the rear sight. Also, see sight.

A firearm, usually a shotgun, with two barrels placed one over the other.

P  Top

The small container located on the side or top of a matchlock, wheel-lock or flint-lock firearm used to hold the priming powder.

a) A small piece of leather or cloth that is greased and placed around a bullet before ramming it down the barrel of a muzzle-loader.
b) Also a piece of cloth drawn through the bore of a firearm to clean it.

Patch box
A small compartment in the butt of a muzzle-loader used to store patches or other small items.

Distribution of the shot in a shotgun charge. This is measured at a standard distance of 40 yards and in a 30 inch circle.

Peep sight
A rear sight with a hole through which the target is viewed. Also known as an aperture sight.

Small round projectiles loaded into shotgun shells. Usually referred to as shot. Also a lead projectile used in some air guns.

The depth that a projectile travels into a target before it stops.

Percussion cap
A small metal explosive filled cup which is placed over the nipple of a percussion firearm.

A small hand-held firearm.

Pneumatic Power
A propulsion system in which compressed air is stored under pressure and when released provides the energy to propel the projectile. A pneumatic gun normally has either a pump system or oxygen cylinder to provide the compressed air.

The general term for any propellant used in firearms which burns upon ignition. The two major types are black powder (an explosive) and smokeless powder (a propellant).

Powder burn
Charring caused by gunshot residue.

Powder charge
The amount of powder by weight in the case of smokeless powder, and by volume, in the case of black powder.

In the case of a black powder firearm, to place powder on the pan or percussion cap on the nipple. Also, to place a primer in a cartridge case.

The overall term for the priming compound, cup and anvil which, when struck, ignites the powder charge.

Primer Pop
The term to describe when a cartridge does not contain the correct amount of gunpowder.

A bullet or shot in flight after firing from a firearm.

The chemical substance which, when ignited, propels the projectile. Also called powder.

The cord used to pull a bore brush or cleaning patch through the bore of a firearm.

Pump action
For registration purposes, a repeating firearm that has a magazine and is manually set in motion usually parallel to the barrel; also called slide action or trombone action.

Q  Top

R  Top

A wood or metal rod used to push the patch and bullet down the barrel of a muzzle-loader.

Range has the following meanings:
a) the distance travelled by a projectile from firearm to target;
b) a projectile’s maximum travelling distance;
c) an area or facility designed for the safe shooting of firearms;
d) dangerous range: the maximum distance at which a projectile will travel; and
e) effective range: the greatest distance a projectile will travel with accuracy.

A firearm’s metal frame that generally contains the of breech, locking and loading mechanisms. Normally the serial number is on the receiver. Also called frame.

The backward movement of a firearm when it is fired. Also called kick.

a) A repeating handgun that has a revolving cylinder with a series of chambers. The cylinder may revolve in either direction, depending on the manufacturer.
b) For registration purposes, a firearm, usually a handgun, that has a revolving cylinder with a series of chambers, and is discharged successively by the same firing mechanism. The chamber may revolve in either direction depending on the manufacturer.

Revolving action
An action with a revolving cylinder containing a number of cartridge chambers. One chamber at a time lines up with the barrel.

The redirection of a projectile after impact, usually with a hard surface. For example, a bullet bouncing off a rock.

A shoulder firearm with a rifled bore. Designed to fire one projectile at a time. Also, see rifling.

Rifled barrel
A barrel with a spiral pattern of grooves cut into its bore for the purpose of imparting a spin on the projectile as it is forced through it.

Rifled slug
A large, single projectile with spiral grooves used in shotguns.

Spiral grooves inside the barrel. Rifling causes the bullet to spin, increasing its accuracy and range. The depressed portions of the rifling are called grooves and the raised portions are called lands.

The edge on the base of a cartridge case. The rim is the part of the case that the extractor grips to remove the cartridge from the chamber.

A cartridge that has its primer located inside the rim of the case. Also, see cartridge.

A rod used for cleaning a firearm. It is used to check for obstructions prior to loading the firearm. It may also be referred to as a ramrod, proving stick or dummy rod.

One shot fired by a firearm. It is also a complete item of ammunition or a cartridge which has all the components needed to fire one shot.

Round nose bullet
A bullet with a rounded nose.

S  Top

A plastic sleeve that holds a slug which is smaller than the bore diameter of a firearm. It is used mainly in shotguns and muzzle loading firearms.

A device that blocks the firing mechanism of a firearm.

See sight.

Part of the firing mechanism linked to the trigger. The sear holds the hammer, firing pin or striker in the cocked position until the trigger is squeezed.

a) An action which fires, extracts, ejects, chambers and cocks with each separate pull of the trigger.
b) For registration purposes, a repeating firearm requiring that the trigger be pulled for each shot fired and which uses the energy of the discharge to perform part of the operating cycle; sometimes called auto-loading or self-loading actions.

Semi-wad cutter
A cylindrical bullet with a short truncated cone at the nose. Often used for paper target shooting.

A complete unit of ammunition consisting of a hull, primer, powder, wad and projectile(s) for use in shotguns.

A shoulder firearm with a smooth bore designed to fire multiple pellets called shot, or a single projectile called a slug.

Shot shell
A cartridge used in a shotgun. It contains multiple shot pellets or a single projectile called a slug.

Side by side
A firearm, usually a shotgun, with two barrels placed side by side.

A firearm device, either mechanical or optical, that helps the shooter aim accurately.

Single action
An action which releases the hammer from a cocked position when the trigger is pulled. Usually found on handguns.

Single action revolver
A revolver which requires the hammer to be cocked manually. Pressing the trigger will not cause it to fire until this is done.

Single shot
A single-barrel firearm that is manually loaded and has no magazine-feed device.

Single stroke pneumatic
Only one stroke is needed to power the gun.

Slide safety
A device that blocks the firing mechanism of a firearm.

A strap used to carry and aid in aiming a rifle.

A large single projectile used in shotguns. Also, see rifled slug.

Small bore
Generally refers to a .22 calibre firearm or rim-fire ammunition.

Smokeless powder
Propellant powder used in modern firearms.

Smooth bore
A firearm with a bore that is not rifled, such as a shotgun.

Soft point bullet
A bullet with a partial jacket exposing a portion of the lead core at the nose.

Spire point bullet
A bullet with a cone-shaped nose.

Spent bullet
A bullet near the end of its flight which has lost nearly all its energy. Despite a loss in energy, spent bullets can still penetrate targets.

Spring Pistol
Also known as spring-air or adiabatic system. A system in which the projectile is propelled by air pressure which is created by a piston moved by a spring.

The part of a rifle or shotgun used in holding the firearm against the shoulder when firing.

T  Top

Tang safety
A device that blocks the firing mechanism of a firearm.

Telescopic sight
See sight.

The path a projectile takes during flight.

The part of the firearm mechanism which releases the part of the action that fires the cartridge.

Trigger guard
The metal loop around the trigger made to protect it and prevent accidentally touching the trigger.

U  Top

V  Top

The speed at which a projectile travels in a given direction.

W  Top

A paper fibre or plastic disc used to separate the powder charge from the shot or slug, to seal propellant gases behind the charge, and to hold the shot together in the barrel.

A cylindrical bullet with a sharp, shouldered, nearly flat nose. It is designed to cut paper targets cleanly so they can be scored accurately.

An early firearm mechanism. A wheel with serrated edges is spun against a piece of iron pyrite. This sends sparks into the pan to ignite the charge.

The adjustment or adjusting mechanism that moves the projectile’s point of impact along the horizontal plane.

Wing safety
A device that blocks the firing mechanism of a firearm.

X  Top

Y  Top

Z  Top