Firearm Types and Actions

AR-15

A widely owned type of semi-automatic rifle originally designed by Armalite. The AR designation stands for Armalite Rifle. Since an AR-15 cannot fire fully automatic, it is not an assault rifle.

Autoloader

A firearm that automatically loads the next cartridge to be fired into the chamber without the shooter having to manually work the action.

Bolt Action

A type of firearm that requires the shooter to manually open and close the bolt between each shot.

Bullpup

A rifle configuration with the action and magazine located behind the trigger. This makes the overall length of the firearm shorter than it otherwise would be.

Carbine

A rifle that is shorter than usual to make it easier to carry and handle.

Deringer

A very small break-action single-shot or multi-barreled pocket pistol.

Double-Action Only (DAO)

A type of semiauto firearm action that cannot be fired in single action, but always fires in double action. DAO guns typically do not have external hammers.

Double Barrel

A shotgun with two barrels either side by side or over and under.

Lever-Action

A rifle action operated by the use of a manual lever.

Long Gun

A term to describe a rifle or shotgun.

Machine Gun

A fully automatic rifle-caliber firearm that fires as long as the trigger is held down.

Revolver

A handgun with a multi-chambered cylinder that rotates to align each chamber one at a time with the barrel and firing pin.

Rifle

A firearm designed to fire a single projectile at a time from the shoulder.

Semi-Automatic

A firearm designed to go through one complete firing cycle with each pull of the trigger.

Shotgun

A smooth bore long gun that can shoot shotshells full of pellets or a single slug.

Single-Shot

A gun that does not have either an internal or external magazine. The cartridge for each shot must be loaded into the chamber manually.

Submachine Gun/Machine Pistol

A fully automatic pistol caliber firearm that can be fired either semi or fully automatic.

Ammunition and Ballistics

Ammo/Ammunition

A blanket term for what a gun fires to shoot a bullet. Modern ammunition consists of a case, propellant, primer, and projectile. Most ammunition fires a single bullet, although shot ammunition for shotguns fires multiple pellets.

Armor-Piercing Ammunition (AP)

A type of ammunition designed to penetrate armor or armor-plated targets such as vehicles. AP bullets have a solid penetrator made of steel or other hardened material. AP ammunition for handguns is not legal for civilians to own because of the risk to police officers, but AP ammunition for rifles is legal for civilians to own.

Ball

Old-fashioned muskets shot a ball-shaped projectile. The use of ball for modern ammunition refers to a fully jacketed bullet with a round nose.

Ballistics

Generally refers to the study of a projectile’s flight. Terminal ballistics is the study of the effect of the impact of a projectile.

Blank Cartridge

A cartridge loaded with propellent but no projectile. Used mainly in theatrical productions and training simulations.

Boat Tail

A type of bullet projectile with a tapered base. The shape reduces drag and makes the bullet more aerodynamic to improve performance.

Bottlenecked Cartridge

A type of cartridge where the bullet diameter is substantially less than the body diameter of the casing resulting in a bottlenecked overall shape.

Brass

Slang term for an empty shell casing.

Bullet

The single metal projectile portion of the cartridge and the part that goes out the barrel when the gun is fired.

Caliber

A measurement of the diameter of the bore of a firearm expressed in tenths of an inch (.45 caliber) or millimeters (9mm).

Cartridge

A complete unit or round of ammunition which includes the case, primer, powder, and bullet.

Cartridge Case

The metal, plastic, or paper casing that contains the internal components of a cartridge.

Centerfire

A cartridge ignited by a primer located in the center of the base of the case.

+P Ammunition (+P+)

Ammunition loaded to a higher power than usual. Guns must be specially rated by the manufacturer to safely fire it.

Rimfire

A type of cartridge that has the primer in the rim of the case rather than using a centerfire primer. Normally only used on small calibers like .22.

Sabot

A lightweight collar surrounding a heavy projectile of reduced caliber. Found on some shotgun slug ammunition.

Shotshell

The cartridge for a shotgun containing multiple pellets.

Slug

A heavy single projectile fired from a shotgun.

Safety and Handling

AD/ND (Accidental/Negligent Discharge)

Short for Accidental Discharge or Negligent Discharge, it refers to a gun discharging when it wasn’t supposed to. Accidental implies that the discharge was beyond the control of the person holding the gun, but this is an extremely rare occurrence. More often the person holding the gun has violated a safety rule and negligently caused the gun to fire making it a negligent discharge.

Backstop

Something that will safely stop a bullet and prevent it from hitting anything beyond the intended target. Examples include a bulletproof wall in an indoor range, a berm plowed up around an outdoor range, or a natural embankment.

Cold Range

A range where your gun must be unloaded until it is your turn to shoot.

Decocker

A lever on a pistol that allows you to safely drop the hammer on a loaded chamber without engaging the firing pin.

Dry Firing

Operating an unloaded gun as a means of practicing trigger pull. It can be performed on modern centerfire guns but should not be used with rimfire guns.

Four Rules of Gun Safety

The four universal rules of firearms safety: Treat all guns as if they are loaded; Never point your firearm at anything you are not willing to destroy; Never put your finger on the trigger unless you are ready to fire; Be sure of your target and what is behind it.

Hot Range

A range where the range master has given the order to commence fire.

Loaded Chamber Indicator

A device usually providing both visual and tactile indication that there is a live round in the chamber.

Muzzle Control

Being aware of and responsible to keep your muzzle pointed in a safe direction at all times.

Safe Direction

Ensuring that the firearm is always pointed in a direction that would safely contain the bullet should it discharge.

Trigger Control

Keeping your finger off the trigger until you are ready to fire, then smoothly squeezing the trigger.

Gun Parts and Mechanics

Action

The action is the internal working mechanism of any gun. It loads the cartridge, fires it, and then removes the spent cartridge.

Adjustable Stock

This means that the stock can be easily adjusted to fit the shooter. The most common form of adjustable stock is the telescoping stock.

Adjustable Trigger

A trigger can be adjusted for the length and weight of the pull.

Barrel

The hollow metal tube the projectile travels through before leaving the muzzle.

Battery

A basic term describing the relationship of the breech or bolt to the chamber. A gun is in battery when the breech is closed and locked. A gun is out of battery when the breech is open and unlocked. This can occasionally occur accidentally with semiautomatic firearms. It is dangerous for a gun to fire when it is out of battery.

Beavertail

A piece of curved metal at the top of the back of the grip of a handgun to protect the shooter’s hand from being bitten by the hammer or slide.

Bipod

A two-legged support for the front end of a rifle or machine gun. It provides stability while shooting.

Blowback

A type of internal action used in low-powered semiautomatic weapons. The breechblock and barrel are not mechanically locked together when the cartridge is fired.

Bore

The hollow portion of a barrel through which the bullet travels.

Butt

The base of a handgun grip and the portion of a long gun stock that goes against the shoulder.

Chamber

The rearmost portion of the barrel where the cartridge rests when it is fired.

Charging Handle/Stripper Clip

A device made from stamped metal that holds a line of cartridges for fast loading into the fixed or detachable magazine of a firearm.

Choke

An insert that screws into a shotgun barrel to adjust the diameter to improve the pattern of shot.

Cylinder

The rotating cartridge holder of a revolver that also serves as the chamber for each round.

Decocker

A lever on a pistol that allows you to safely drop the hammer on a loaded chamber without engaging the firing pin.

Ejector

A device in a firearm action that ejects spent and unfired cartridges.

Extractor

A device in a firearm action that extracts spent or unfired cartridges from the chamber.

Firing Pin

The thin metal rod that strikes the cartridge primer when the trigger is pulled.

Firing Pin Block

A passive internal safety that stops the firing pin from striking the cartridge primer unless the trigger is pulled.

Flash Hider/Flash Suppressor

A device on the muzzle that reduces the flash when the gun is fired.

Folding Stock

A type of long gun stack that folds over to make the gun more compact.

Forend

The part of a long gun stock forward of the action where you hold the gun to fire it.

Frame

The part of a handgun to which everything else is attached.

Grip/Grip Panels

The handle of a handgun and the panels that make up the gripping surfaces.

Hammer

The component of the action that strikes the firing pin to drive it forward into the primer. Hammers can be external or internal.

Magazine

A box-like container for cartridges that can be either fixed or removable and feeds ammunition to the firearm.

Muzzle

The open front end of the barrel.

Rail

An adapter that allows accessories like lights and optics to be mounted on a firearm.

Receiver

The portion of a gun that houses the action. Also the portion of a firearm regulated by firearms laws.

Recoil Spring

A powerful spring that cushions the slide as it travels to the rear and then sends it forward again to drive a fresh round into the chamber.

Slide

The upper portion of a semi-automatic pistol that houses the barrel and bolt assembly of the firing mechanism. The slide moves back and forth on rails with each shot to eject the spent case, load a new cartridge, and cock the action for the next shot.

Stock

The rear portion of a rifle or shotgun that includes the part that rests against the shoulder. It can be made of wood, metal, or plastic.

Trigger

The small lever the shooter pulls or presses to fire the gun. Pulling the trigger releases the hammer or striker which goes forward and ignites the primer in the base of the cartridge. In double-action guns, the trigger also re-cocks the hammer for the next shot.

Trigger Guard

A band of metal or plastic running around the trigger to protect it and prevent it from being pulled by accident.

Shooting Techniques and Practices

Benchrest (Shooting)

Shooting performed from a solid mechanical rest to eliminate variables in aiming due to being held by a person. It is a form of competition shooting but is also used to accurately sight in optics and scopes.

Controlled Pair vs. Double Tap

A controlled pair is two shots fired in rapid succession when a sight picture is obtained before each shot. A double tap is two shots fired in rapid succession only using the sight picture from the first shot.

Cross-Dominant

A shooter whose dominant eye is the opposite of his/her dominant hand, such as right-handed but left-eyed.

Follow Through

Holding the trigger to the rear after the shot has been fired until the sights are back on target.

Limp Wristing

Failure to keep the wrist locked while firing a handgun. It frequently causes malfunctions in semiautomatic pistols.

Point Shooting

Shooting without using the sights. The shooter uses arm and body position to “aim” the gun at the target.

Practical Shooting

A tactical shooting sport that simulates the use of a firearm in practical situations such as self-defense.

Sight Alignment/Sight Picture

The manner in which the sights are lined up properly in front of the shooter’s eye to form a straight path to the target and the image the shooter sees when doing so.

Stance (Weaver, Isosceles)

Methods of positioning the body when shooting. Examples of stances are Weaver and Isosceles.

Tap, Rack, Bang

The procedure to clear a misfeed; tap the base of the magazine firmly to be sure it is properly seated, rack the slide to eject an empty case/feed a new round, and pull the trigger.

Optics and Sights

Aperture Sight

Sometimes referred to as a peep sight, it refers to a rear sight, usually on a rifle or shotgun, that consists of a tang with a hole in it through which the shooter sights on the front sight.

Ghost-Ring Sight

A type of aperture rear sight with a thin rim around the opening that highlights the opening but fades out when the shooter looks through it.

Iron Sights

The standard mechanical sighting system of any gun.

Laser

A sighting device that uses a laser to create a dot on the target.

Night Sights

A type of iron sights that glow or shine in the dark.

Optics

A blanket term for optical sights such as red dot, reflex sights, and scopes.

Peep Sight

A slang term for an Aperture Sight.

Red Dot Sight

An optical sight that provides fast target acquisition by using an internal illuminated dot as an aiming point.

Scope/Telescopic Sight

An optical sight that magnifies the target to bring it closer at long range.

Miscellaneous Terms

Antique

A firearm manufactured before 1900.

ACP (Automatic Colt Pistol)

An abbreviation for Automatic Colt Pistol. The acronym denotes a specific set of calibers that include .45ACP, .380ACP, and .32ACP designed by John Moses Browning for the Colt Firearms Company for a specific set of handguns.

Bayonet Lug

A lug on a rifle or shotgun barrel intended for use in mounting a bayonet or other accessory.

Black Powder

The firearms propellant originally used in antique muzzleloaders and older breechloading guns. It has been replaced by modern smokeless powder except in antique and reproduction muzzleloaders and breechloading guns. It is unstable and highly explosive as compared to modern smokeless powder.

CAN (Slang for Sound Suppressor)

Slang term for a sound suppressor.

Cover/Cover Garment

Anything someone can hide behind that will probably stop a bullet. A piece of clothing that covers a concealed firearm.

Ear Protection

Hearing protection for use when shooting. Can be earplugs, earmuffs, or electronic hearing protection.

Fouling

Black residue in a gun after prolonged firing.

Gauge

The term that designates the size of a shotgun bore. It is determined by the number of round lead balls of bore diameter that equals a pound.

Grains

A unit of weight measurement for bullets and gunpowder.

High-Capacity Magazine

A vague term to describe a magazine holding more rounds than the speaker might consider “average.” Generally, a politicized term used in the anti-gun community.

Hollow-Point Bullet

A bullet with a cavity in its nose to increase expansion on penetration of a solid target.

NFA 34 (National Firearms Act of 1934)

The set of federal regulations that govern the sale and possession of certain types of firearms.

Silhouette Shooting

Shooting heavy metallic targets with a handgun or long gun.

Suppressor (Silencer)

A device that reduces the sound of a gun firing at the muzzle. It does not silence a shot and is significantly louder than often portrayed in movies.

Conclusion

Those are just a few of the more common terms used in shooting sports. There are plenty more specific to various activities and firearms, but that should get most new shooters started.