Dirty Bird’s Gun Glossary: Firearms & Ammunition Terms

A

Accurize:
The process of modifying a firearm to enhance its precision, often involving adjustments to the barrel, trigger, or sights.

Action:
The mechanism that loads, fires, and ejects a cartridge in a firearm. Types include bolt action, lever action, pump action, semi-automatic, and automatic. In pistols, actions can be double-action (DA), where the trigger pull cocks and releases the hammer, or single-action (SA), where the hammer must be manually cocked.

Adjustable Sights:
Sights that can be fine-tuned for windage (left-right) and elevation (up-down) to improve accuracy at various distances.

Ammunition:
The complete cartridge, consisting of a bullet, casing, propellant powder, and primer, used in firearms. Also called “ammo.”

Anti-Glare:
A textured or grooved surface above the barrel to reduce light reflection and improve target visibility.

Armor-Piercing:
Ammunition with a hardened core, designed to penetrate body armor or hard surfaces.

AR-10:
A semi-automatic rifle designed by Eugene Stoner, chambered for larger calibers like 7.62x51mm NATO, valued for its modularity and accuracy.

AR-15:
A lightweight, modular semi-automatic rifle, typically chambered in 5.56x45mm NATO, popular for sport shooting, hunting, and defense.

Automatic:
A firearm that fires more than one round per single function of the trigger, also known as full-auto. Heavily regulated in many regions.

Autoloader:
A firearm that automatically loads the next round into the chamber after firing, synonymous with semi-automatic.

B

Backstrap:
The rear portion of a pistol’s grip frame, sometimes interchangeable to accommodate different hand sizes.

Ballistics:
The science of a projectile’s motion, encompassing internal (in-barrel), external (in-flight), and terminal (on-impact) phases.

Bandolier:
A shoulder-worn belt with pockets for holding ammunition, commonly used for shotgun shells.

Barrel:
The metal tube through which a bullet travels when fired, guiding its path and affecting accuracy.

Barrel Nut:
A component securing the barrel to the receiver or handguard, often allowing quick barrel changes in some designs.

Binary Trigger:
A trigger that fires one round when pulled and another when released, increasing the firing rate in semi-auto firearms.

Bipod:
A two-legged support device attached to a rifle for stability during shooting, often used in long-range applications.

Birdshot:
Small, spherical pellets loaded in shotgun shells, designed for hunting birds or clay target shooting.

Black Powder:
A traditional gunpowder mixture of charcoal, sulfur, and potassium nitrate, used in muzzleloaders and historical firearms.

Blowback:
A semi-automatic or automatic firearm design that uses the pressure of the fired cartridge to cycle the action.

Bolt:
A component that seals the breech, chambers a round, and extracts the spent casing in bolt-action or semi-auto firearms.

Bolt Carrier Group (BCG):
Bolt Carriers are simply housings that carry the bolt of a firearm. Many platforms have bolt carriers, AK, AR-180, HK, etc

Bore:
The interior of a firearm’s barrel, its diameter determining the caliber or gauge.

Boresight:
A preliminary alignment of a firearm’s sights with its barrel to simplify zeroing.

Break Action:
A design where the barrel hinges open to load or unload, common in shotguns and some rifles.

Breech:
The rear of the barrel where a cartridge is loaded and fired.

Buckshot:
Large, spherical pellets, typically .24 inches or larger, loaded in shotgun shells for hunting or self-defense.

Bullet:
The projectile portion of a cartridge, fired from the barrel.

Bull Barrel:
A thick, heavy barrel designed to reduce vibration and improve accuracy, often used in precision shooting.

Bullpup:
A firearm with the action and magazine behind the trigger, allowing a shorter overall length with a standard barrel.

Buttstock:
The part of a rifle or shotgun that rests against the shooter’s shoulder for stability.

C

Caliber:
The diameter of a firearm’s bore or bullet, measured in inches (e.g., .45) or millimeters (e.g., 9mm).

Cant:
Tilting a firearm slightly when aiming, which can disrupt shot accuracy.

Carbine:
A short-barreled rifle designed for maneuverability, often used in close-quarters scenarios.

Cartridge:
A single unit of ammunition, including the case, primer, propellant, and bullet or shot.

Carry Handle:
A detachable handle on rifles like the AR-15, often incorporating a rear sight.

Centerfire:
Ammunition with a primer in the center of the cartridge base, used in most modern firearms.

Chamber:
The part of the barrel that holds the cartridge before firing.

Charging Handle:
A component that manually cycles the action, typically on semi-auto rifles like the AR-15 or AR-10.

Choke:
A constriction at a shotgun’s muzzle to control the spread of shot, optimizing range or pattern.

Clip:
A device that holds cartridges together for quick loading into a magazine or firearm, often confused with a magazine.

Cock:
Manually drawing back the hammer or striker to prepare a firearm for firing.

Compensator:
A muzzle device that redirects gases to reduce recoil and muzzle rise.

Concealed Carry:
Carrying a hidden firearm on one’s person. It fires more than one round per single function of the trigger.

Crosshair:
A reticle pattern in an optic, typically intersecting lines forming a cross, used for precise aiming.

Cylinder:
The rotating component in a revolver that holds multiple cartridges, aligning each with the barrel for firing.

D

DA/SA (Double Action/Single Action):
A pistol trigger system where the first shot is double-action (longer pull cocks and fires) and subsequent shots are single-action (shorter pull).

Decocker:
A mechanism that safely lowers a cocked hammer without firing, found on some DA/SA pistols.

Defensive Ammunition:
Rounds designed for self-defense, typically hollowpoints that expand to maximize stopping power.

Derringer:
A small, concealable pistol with one or two barrels, historically used for self-defense.

Double Tap:
Firing two shots in quick succession at the same target, often without re-aiming.

Drop Safety:
A feature preventing a firearm from discharging if accidentally dropped.

Drum Magazine:
A cylindrical, high-capacity magazine that stores rounds in a spiral for rapid feeding.

Dry Fire:
Practicing trigger pull without live ammunition to improve technique, requiring a verified unloaded firearm.

Dud:
A cartridge that fails to fire after the primer is struck, also called a misfire.

Duty Pistol:
A handgun built for reliability and durability, often used by law enforcement or military personnel.

E

Ejection Port:
The opening where spent casings are expelled from a firearm after firing.

Ejector:
A part that pushes the spent casing out of the ejection port.

Extractor:
A component that pulls the spent casing or live round from the chamber.

Eye Protection:
Safety glasses or goggles worn to shield eyes from ricochet or debris during shooting.

Eye Relief:
The distance from the shooter’s eye to an optic’s lens for a clear, full sight picture.

F

Firearm:
A rifle, shotgun, or handgun that uses gunpowder as a propellant, per federal definition.

Firing Pin:
The part that strikes the primer to ignite the cartridge’s propellant powder.

Flash Hider:
A muzzle device that reduces visible muzzle flash by dispersing gases, aiding low-light shooting and concealing the shooter’s position.

Flip-Up Sights:
Backup iron sights that fold down when not in use, often paired with optics.

FMJ (Full Metal Jacket):
A bullet with a lead core encased in a metal jacket, designed for penetration with minimal expansion.

Foregrip:
A handle mounted under the barrel to improve control, available in vertical or angled designs.

Frangible:
Ammunition that breaks apart on impact, reducing over-penetration, often used in training or close-quarters scenarios.

Free-Float Handguard:
A handguard not in contact with the barrel, enhancing accuracy by minimizing vibration.

Front Sight:
The sight at the muzzle end of the barrel, used with a rear sight for alignment.

Full-Auto:
A firearm that fires continuously while the trigger is held, synonymous with automatic.

FFL (Federal Firearms License):
A U.S. license required to manufacture, sell, import or transfer firearms commercially.

G

Gas Block:
A component in gas-operated firearms that directs propellant gases to cycle the action.

Gas System:
The mechanism in semi-auto or automatic firearms that uses gas from a fired round to cycle the action.

Gauge:
A shotgun’s bore measurement, based on the number of lead balls of bore diameter equaling one pound (e.g., 12-gauge).

Ghost Ring Sights:
Iron sights with a large, circular rear aperture and a front post, designed for fast target acquisition, common on shotguns and tactical rifles.

Glock:
A brand of polymer-framed, striker-fired semi-automatic pistols known for reliability, simplicity, and widespread use in law enforcement and civilian defense.

Grain:
A unit of weight for bullets and powder, where 1 grain equals 1/7,000 of a pound.

Grip:
The part of a firearm held by the hand, designed for control and comfort, often textured or ergonomic.

Grooves:
Spiral cuts in a rifled barrel that spin a bullet for stability and accuracy.

Gunsmith:
A professional skilled in repairing, modifying, or building firearms.

Gun Safe:
A secure storage unit to prevent unauthorized access to firearms.

H

Hair Trigger:
A trigger with an extremely light pull weight, requiring minimal pressure to fire, often used in precision shooting.

Hammer:
A component in some firearms that strikes the firing pin or primer to initiate firing.

Handguard:
A cover around the barrel to protect the shooter’s hand and mount accessories like rails or grips.

Headspace:
The distance from a cartridge’s base to the point it contacts the chamber, critical for safe and reliable firing.

Hollowpoint:
A bullet with a hollowed tip that expands on impact, increasing stopping power and reducing over-penetration, ideal for self-defense.

Hop-Up:
An airsoft term for a system that adds backspin to BBs, improving range and accuracy.

Hunting Rifle
A rifle optimized for hunting, typically with a scoped, high-accuracy design and calibers suited for game.

I

Iron Sights:
Non-optical metal sights, typically a front post and rear notch, used for aiming.

Isosceles Stance:
A shooting stance with both arms extended and feet shoulder-width apart, resembling an isosceles triangle.

Internal Lock:
A built-in safety mechanism to prevent unauthorized firing, often key-operated.

J

Jacketed Hollow Point (JHP):
A hollowpoint bullet with a metal jacket, balancing expansion and penetration for self-defense.

Jam:
A malfunction where a firearm fails to cycle, feed, or eject properly, requiring clearing.

Jerking the Trigger:
Pulling the trigger abruptly, which can disrupt aim and reduce accuracy.

K

KAK (Knight’s Armament Company):
A U.S. manufacturer known for high-quality AR-style rifles, suppressors, and accessories like the SR-15 and SR-25.

KeyMod:
A modular rail system for attaching accessories, lighter than Picatinny but less common today.

Kick:
Informal term for recoil, the backward force felt when firing a firearm.

Kryptek Camo:
A modern camouflage pattern designed for tactical and hunting environments.

L

Lands and Grooves:
The raised (lands) and recessed (grooves) areas in a rifled barrel that impart spin to a bullet.

Lever Action:
A firearm where a lever cycles the action to load and eject rounds, iconic in Western rifles.

LMT (Lewis Machine & Tool):
A U.S. company producing precision AR-style rifles, like the MWS, known for reliability and modularity.

Loaded Chamber Indicator:
A feature showing whether a round is in the chamber, enhancing safety.

Long Gun:
A firearm with a long barrel, such as a rifle or shotgun, distinct from handguns.

Lower Receiver:
The part of an AR-style firearm housing the trigger group, magazine well, and fire control. It is legally considered a firearm in the US.

Luger:
A semi-automatic pistol (e.g., German P08) or its 9mm Parabellum cartridge, historically significant.

M

Magazine:
A device that stores and feeds cartridges into a firearm’s chamber, detachable or fixed.

Magwell:
The opening where a magazine is inserted, sometimes flared for faster reloads.

Mil-Spec:
A military specification standard ensuring components meet rigorous performance criteria.

M-Lok:
A modular rail system for mounting accessories, using slots for lightweight, secure attachments.

Muzzle:
The front end of a barrel where the bullet exits.

Muzzle Brake:
A device that redirects gases to reduce recoil, often increasing noise.

Muzzle Device:
Any attachment at the muzzle, such as a flash hider, brake, or suppressor.

Muzzle Flash:
The visible light emitted when a firearm is fired, caused by burning gases.

Muzzleloader:
A firearm loaded through the muzzle with loose powder and a projectile, common in historical or black powder shooting.

N

NFA (National Firearms Act):
A U.S. law regulating items like suppressors, short-barreled rifles, and automatic firearms.

Night Sights:
Sights with tritium or luminescent inserts for aiming in low-light conditions.

Non-Corrosive Ammo:
Ammunition with primers that don’t leave corrosive residue. Essentially all modern ammo is non-corrosive, simplifying maintenance.

Neck (of Cartridge):
The tapered section of a cartridge case that secures the bullet.

O

Optics:
Sighting devices like scopes, red dots, or holographic sights for enhanced accuracy.

Over-Under:
A double-barreled shotgun or rifle with barrels stacked vertically, popular for sporting clays.

Open Carry:
Carrying a firearm visibly in public, subject to local laws.

O-Ring:
A rubber seal used in some firearms to ensure gas-tight connections in the action.

P

Parallax:
An optical error where the reticle appears to shift against the target if the shooter’s eye moves off-center.

Pistol:
A handgun designed for one- or two-handed firing, including semi-auto and revolver types.

Pistol Caliber Carbine (PCC):
A carbine chambered for pistol rounds, like 9mm, for easier handling.

Picatinny Rail:
A standardized rail system for mounting optics, lights, and other accessories.

Plinking:
Informal shooting at improvised targets, like cans, for fun and practice.

Ported Barrel:
A barrel with vents to reduce recoil or muzzle rise, common in competition firearms.

PPK:
A compact semi-automatic pistol designed by Walther, chambered in .380 ACP or .32 ACP, known for its sleek design and use in espionage contexts.

Primer:
A small, shock-sensitive component in a cartridge that ignites the propellant powder.

Propellant:
The chemical composition (e.g., gunpowder) that burns to propel a projectile when ignited.

Pump Action:
A firearm where a sliding forend cycles the action, common in shotguns and some rifles.

Q

Quad Rail:
A handguard with four Picatinny rails for mounting multiple accessories.

Quick Detach (QD):
A system for rapidly attaching or removing accessories, like slings or suppressors.

R

Rail Panels:
Covers or grips attached to Picatinny, M-Lok, or KeyMod rails to improve handling, protect hands, or reduce weight.

Rail System:
A mounting platform, like Picatinny or M-Lok, for attaching firearm accessories.

Receiver:
The main body of a firearm that houses the action, trigger, and other components.

Recoil Pad:
A cushioned attachment on a stock to absorb recoil and improve shooter comfort.

Red Dot Sight:
An optic projecting a red (or other color) dot for fast, intuitive aiming.

Recoil:
The backward force generated when a firearm is fired, felt by the shooter.

Reloading:
Assembling ammunition from components (cases, primers, powder, bullets) or preparing a firearm to fire again.

Reticle:
The aiming pattern in an optic, such as a crosshair, dot, or mil-dot, used to align the shot with the target.

Rimfire:
Ammunition with a primer in the rim of the cartridge base, like .22 Long Rifle.

Rifling:
Spiral grooves in a barrel that spin a bullet for improved accuracy and stability.

Rifle:
A long gun with a rifled barrel, designed for precision shooting at longer ranges.

RMR (Ruggedized Miniature Reflex):
A compact, durable red dot sight, often used on pistols or rifles.

Round:
A single cartridge of ammunition, ready to be fired.

S

Safety:
A mechanism to prevent accidental firing, such as a manual switch, trigger safety, or grip safety.

Scope:
An optical device that magnifies a target for precise long-range aiming.

Sear:
A component that holds and releases the hammer or striker to fire a round.

Semi-Auto:
A firearm that fires one round per single function of the trigger pull and automatically reloads.

Shotgun:
A long gun firing shot (pellets) or slugs, typically with a smooth bore, used for hunting or defense.

Shotgun Slug:
A single, heavy projectile fired from a shotgun, designed for accuracy and impact over longer ranges than shot.

Short-Barreled Rifle (SBR):
A rifle with a barrel under 16 inches, regulated under the NFA in the U.S.

Silencer:
A device that reduces a firearm’s noise and muzzle flash, also called a suppressor.

Single Action:
A trigger system requiring the hammer to be manually cocked before firing.

Slide:
The reciprocating part of a semi-auto pistol that cycles the action and houses the barrel.

Sling:
A strap for carrying or stabilizing a firearm during shooting.

Smithing:
The craft of repairing, modifying, or building firearms by a gunsmith.

Suppressor:
A device that muffles a firearm’s sound and reduces recoil, synonymous with silencer.

Stippling:
Texturing a grip, often on polymer firearms, to improve handling and control.

Striker-Fired:
pistol design using a spring-loaded striker instead of a hammer, common in modern handguns like Glocks.

Stock:
The part of a rifle or shotgun that provides shoulder support, available in fixed, folding, or adjustable designs.

T

Tactical:
Firearms or gear designed for military, law enforcement, or defensive applications, emphasizing functionality.

Take Down:
Disassembling a firearm for cleaning or transport, or a design that facilitates easy breakdown.

Tap Rack Bang:
A drill to clear malfunctions by tapping the magazine, racking the slide, and attempting to fire.

Telescopic Sight:
A scope with magnifying lenses for long-range precision shooting.

Threaded Barrel:
A barrel with external threads for attaching muzzle devices like suppressors or flash hiders.

Trajectory:
The curved path a projectile follows from muzzle to impact, influenced by gravity and air resistance.

Trigger:
The component squeezed to fire a firearm, initiating the firing sequence.

Trigger Guard:
A protective loop around the trigger to prevent accidental activation.

Two-Stage Trigger:
A trigger with an initial light take-up followed by a crisp break, common in precision rifles.

U

Underfolder:
A folding stock that tucks under the firearm, reducing length for storage or transport.

Unloaded:
A firearm with no ammunition in the chamber or magazine, verified for safety.

Upper Receiver:
The part of an AR-style firearm housing the barrel, bolt, and charging handle, detachable from the lower receiver.

V

Velocity:
The speed of a bullet, measured in feet per second (fps) or meters per second, affecting range and impact.

Vent Rib:
A raised rib on a shotgun barrel that aids heat dissipation and sight alignment.

Vertical Foregrip:
A grip mounted under the barrel, positioned at 90° to the bore axis, to enhance control, especially during rapid fire.

W

Wadcutter:
A flat-nosed bullet designed to cut clean holes in paper targets, often used in competitive shooting.

Weaver Rail:
A mounting system for optics and accessories, narrower than Picatinny but compatible with many devices.

Weapon Light:
A firearm-mounted light for illuminating targets in low-light conditions.

Windage:
The horizontal adjustment of a sight to compensate for wind or misalignment.

Winchester:
A renowned firearms and ammunition brand, or specific cartridges like .308 Winchester.

Wrist Brace:
A stabilizing device for pistol-like firearms, often used with AR pistols to enhance control.

X

X-Ray Sights:
Informal term for high-visibility sights, often with fiber optics or tritium for enhanced aiming.

X-Ring:
The precise center of a target, used in competitive shooting to denote perfect accuracy.

Y

Yaw:
The side-to-side wobble of a bullet in flight, which can affect stability and accuracy.

YHM (Yankee Hill Machine):
A manufacturer of firearm accessories, including muzzle devices, rails, and suppressors.

Z

Zeroing:
Adjusting a firearm’s sights or optics to align the point of aim with the point of impact at a specific distance.

Zinc Alloy:
A material used in some firearm components for cost-effective durability, though less robust than steel.

Zombie Ammo:
A marketing term for novelty or high-performance ammunition, often with unique aesthetics.