Glossary
Specialized jargon used across the blog — terms of art, project-specific shorthand, and acronyms — each with a short definition and a link to a fuller page.
Use the A–Z jump bar to scan, or click a term for the longer explanation. Posts that use a term link to it from their sidebar.
121 terms · 19 letters
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John Browning's iconic single-action semi-automatic pistol, originally adopted as the M1911 by the US Army.
A
The mechanism that loads, fires, and ejects ammunition in a firearm.
A modular semi-automatic rifle platform; the most common centerfire sport rifle in the US.
The Bureau of Alcohol, Tobacco, Firearms and Explosives — the US federal agency regulating firearms.
B
Material or terrain behind the target that will reliably stop a bullet.
The metal tube through which the projectile travels when fired.
Shotgun ammunition loaded with many small pellets.
The part that locks the cartridge into the chamber and houses the firing pin.
A manually-operated action where the shooter cycles the bolt by hand to load each round.
The assembly that houses the bolt and cycles the action of a semi-auto rifle.
The interior surface of the barrel through which the bullet travels.
An action that hinges open at the breech for loading and unloading.
Shotgun ammunition with fewer, larger pellets.
The projectile component of a cartridge — not the entire round.
C
The bore diameter of a firearm or the diameter of its bullet.
A complete unit of ammunition: case, primer, powder, and bullet.
The metal cylinder that holds the powder and seats the bullet.
A command halting all shooting, with firearms made safe and benched or holstered.
Cartridges with the primer in the center of the case head.
The portion of the firearm that holds the cartridge in firing position.
The control used to manually cycle the action.
To verify a firearm is unloaded by removing the magazine and inspecting the chamber.
A 1911-style pistol carried with a round chambered, hammer cocked, and the manual safety engaged — equivalent to Condition 1.
A range protocol where firearms are unloaded and cased or holstered between strings.
Carrying a firearm in a manner that is not openly visible.
Fully ready to fire: round chambered, hammer cocked, manual safety off.
Cocked and locked: a round chambered, hammer cocked, manual safety engaged.
A 1911-style pistol carried with a round in the chamber and the hammer manually lowered (de-cocked).
Magazine loaded, chamber empty, hammer down — known as Israeli carry.
The rotating part of a revolver that holds individual cartridges.
D
Slang for the trigger-safety blade in the center of a Glock-style striker-fired trigger.
A trigger system where pulling the trigger both cocks and releases the hammer.
The sequence of motions that takes a holstered handgun to a ready-to-fire position on target.
A receiver with threaded holes for mounting accessories — typically scope bases on a rifle.
A firearm designed to not discharge if dropped onto a hard surface.
Practicing trigger press, draw, and manipulation with an unloaded firearm.
An inert cartridge used for safe dry-fire and malfunction practice.
E
The part that throws the spent case out of the firearm after firing.
A claw that pulls the spent case out of the chamber after firing.
F
A malfunction where the firearm fails to chamber a fresh round from the magazine.
Fire Control Unit — the serialized internal trigger group of a modular pistol; legally the firearm.
Federal Firearms License — required to engage in the business of dealing or manufacturing firearms.
The component that strikes the primer to ignite the cartridge.
An internal safety that blocks the firing pin until the trigger is fully pulled.
Pointing the muzzle at a person or thing you do not intend to shoot.
Full Metal Jacket: a bullet with a soft lead core fully encased in a harder metal shell.
Maintaining sight picture and trigger control through the shot and into the next.
The portion of a long gun's stock forward of the trigger guard, gripped by the support hand.
The main body of a handgun that houses the action.
Forced Reset Trigger — a trigger that mechanically resets after each shot using the bolt's cycling motion.
G
Component on the barrel that taps gas to cycle the action of a gas-operated firearm.
Shotgun bore measurement; lower numbers indicate larger bores.
A unit of weight used for bullets and powder; 437.5 grains equals one ounce.
The portion of a firearm held by the shooting hand.
A spring-loaded safety on the rear of the grip that must be depressed (by a firm grip) before the firearm will fire.
H
A spring-loaded part that strikes the firing pin or the cartridge primer.
A perceptible delay between trigger pull and discharge.
A bullet with a cavity in the tip designed to expand on impact.
A device that retains and protects a firearm while carried, covering the trigger guard.
A range protocol where shooters carry loaded, holstered firearms throughout the relay.
I
Non-optical sights — a front sight and a rear sight aligned by eye.
A square shooting stance with both arms equally extended toward the target, forming a triangle with the chest.
L
Loaded Chamber Indicator — a visual or tactile feature that signals whether a round is in the chamber.
A manually-operated action cycled by a lever beneath the receiver.
M
Firing every round in a magazine as fast as the trigger can be pressed.
The control that drops the magazine out of the firearm for removal or reload.
A spring-loaded ammunition feeding device that holds rounds for cycling into the chamber.
Any failure of a firearm to fire, feed, extract, or eject as intended.
Failure of a cartridge to fire when the primer is struck.
The forward-most opening of a firearm's barrel, where the bullet exits.
Always keeping the muzzle pointed in a safe direction.
N
An unintentional discharge caused by violation of one of the safety rules.
The National Firearms Act of 1934 — regulates suppressors, short-barreled rifles and shotguns, machine guns, and other items.
National Instant Criminal Background Check System — used by FFLs to clear retail firearm sales.
O
Carrying a firearm in a manner that is openly visible.
A handgun sold with a slide cut and adapter plates ready to mount a red-dot optic.
P
A standardized accessory mounting rail with crosswise slots.
A grip extending vertically from the receiver, gripped like a pistol.
The propellant inside a cartridge that burns to drive the bullet.
Personal protective equipment — eye and ear protection at minimum.
Confirming whether the chamber is loaded by partially retracting the slide or bolt.
A small impact-sensitive cap at the base of the cartridge that ignites the powder.
A manually-operated action cycled by sliding a forend back and forth.
R
The serialized portion of a firearm that holds the action; legally the firearm itself.
The rearward force experienced when firing, equal-and-opposite to the bullet's forward momentum.
A non-magnifying optic projecting an illuminated reticle onto a lens.
A handgun with a rotating cylinder of multiple chambers.
Spiral grooves cut into the bore that spin the bullet for stability.
Cartridges with the primer compound spread inside the rim of the case.
Casual synonym for cartridge.
S
A direction in which an unintentional discharge would not cause harm or property damage.
A mechanical device intended to prevent unintentional discharge.
A magnifying optic mounted on a rifle for medium-to-long-range shooting.
An internal part that holds the hammer or striker until the trigger is pulled.
A firearm that fires one round per trigger pull and uses recoil or gas to chamber the next.
Centering the front sight in the rear sight notch with equal light on both sides.
The visual relationship of front sight, rear sight, and target as seen by the shooter.
Aiming devices on top of the firearm — front sight, rear sight, or optic.
A trigger system where the trigger only releases the hammer; the hammer must be cocked separately.
The reciprocating top half of a semi-automatic pistol that cycles the action.
A milled cutout on a pistol slide for mounting a red-dot optic.
A lever that holds the slide to the rear when the magazine is empty, and that some shooters use to release it.
A strap that lets the shooter carry a long gun and stabilize it while shooting.
A single solid projectile loaded into a shotgun shell.
An inert dummy cartridge used for safe dry-fire practice and function checks.
A round that fires with insufficient power to push the bullet out of the bore — extremely dangerous.
The portion of a long gun braced against the shoulder.
A malfunction where a spent case is caught in the ejection port, sticking up like a stovepipe.
A spring-loaded firing pin used in place of a hammer in many modern pistols.
A device that reduces the audible report and muzzle flash of a firearm.
T
A lever or pin used to release a pistol's slide for disassembly.
The standard immediate-action drill for clearing many semi-auto malfunctions.
The four foundational firearms safety rules — the rules that prevent every accidental injury.
A barrel with threads cut at the muzzle for attaching a suppressor or muzzle device.
The lever the shooter presses to release the sear and fire the firearm.
Keeping the finger off the trigger and outside the trigger guard until ready to fire.
The protective loop around the trigger that prevents accidental contact.
The deliberate, smooth rearward movement of the trigger to fire the shot.
The forward release of the trigger after firing to the point where it can be pressed again.
W
A flashlight mounted to a firearm to identify targets in low light.
A shooting stance with the support-side foot back, support hand pulling, strong hand pushing.