Gun Terms
Glossary

A popular rimfire cartridge known for its low recoil, affordability, and versatility — ideal for target shooting, training, small game hunting, and plinking.

A high-velocity rimfire cartridge offering flatter trajectory and more energy than .22 LR, suitable for small game hunting and varmint control at longer ranges.

A magnum rimfire cartridge providing significantly more power and range than .22 LR, effective for medium-sized game and varmint hunting.

A standardized rifle cartridge commonly used in AR-15 platform rifles. Offers high velocity with moderate recoil, suitable for target shooting, competition, and defensive applications.

A common intermediate rifle cartridge most associated with the AK platform. Known for reliable operation and moderate power at shorter ranges.

The Soviet counterpart to 5.56 NATO, used in AK-74 variants. Features a smaller diameter bullet with higher velocity and flatter trajectory.

A versatile cartridge designed for AR-15 platforms offering excellent performance from short barrels while maintaining compatibility with standard magazines.

A full-power rifle cartridge used in battle rifles and precision rifles. Offers excellent accuracy and power at longer ranges.

A precision rifle cartridge designed for long-range target shooting and hunting. Features excellent ballistic coefficient and minimal recoil for its power class.

A time-tested American cartridge with excellent power and versatility for hunting various game sizes.

A magnum rifle cartridge offering exceptional long-range performance for hunting and precision shooting.

The world's most popular handgun cartridge, offering balanced performance, moderate recoil, and high magazine capacity.

A classic American handgun cartridge known for its larger diameter bullet and subsonic velocity, favored for defensive applications.

An intermediate handgun cartridge developed to offer more power than 9mm with higher capacity than .45 ACP.

A revolver cartridge known for excellent power and accuracy, also available in semi-automatic pistols as .357 SIG.

A high-performance handgun cartridge offering power approaching magnum revolver cartridges in a semi-automatic platform.

The most popular shotgun gauge, offering versatility for hunting, sport shooting, and defensive applications with various load types.

A lighter alternative to 12 gauge, offering reduced recoil while maintaining effectiveness for hunting and sport shooting.

The smallest shotgun gauge, providing low recoil in a compact package suitable for small game and sport shooting.

Automatic Colt Pistol — a designation for several cartridges designed by John Browning for Colt semi-automatic pistols. Examples include .45 ACP and .380 ACP.

The functional components of a firearm that load, fire, and eject a cartridge. Also refers to the method of operation — bolt-action, lever-action, auto-loading, etc.

Stands for Avtomat Kalashnikova, named after designer Mikhail Kalashnikov — "Kalashnikov's Automatic Rifle." The "47" refers to 1947, when the rifle was first developed.

The successor to the AK-47 — Avtomat Kalashnikova Modernizirovannyy. Introduced stamped components for the receiver and is the most common AK variant.

Controls or designs that allow equally easy use by both right- and left-handed shooters, providing flexibility and comfort for all users.

A catch-all term for cartridges or projectiles intended to be launched from a weapon system.

A process in which metal (typically aluminum) is coated with a protective oxide layer through an electrochemical process, enhancing durability, corrosion resistance, and allowing for color customization.

Components designed to prevent trigger and hammer pins in firearms like the AR-15 from shifting out of place during use, ensuring consistent performance under heavy use or recoil.

Stands for ArmaLite Rifle. A lightweight, gas-operated, magazine-fed rifle known for its modularity and customization options, popular in both military and civilian applications.

A semi-automatic, gas-operated rifle chambered in .308 Winchester, designed for long-range precision. The predecessor to the AR-15.

A lightweight, semi-automatic rifle chambered typically in .223 Remington or 5.56 NATO. Known for its modular design and wide range of aftermarket parts and accessories.

Bureau of Alcohol, Tobacco, Firearms and Explosives — the federal agency responsible for regulating firearms, enforcing gun laws, and overseeing the sale and ownership of NFA-regulated items in the United States.

Firearms that automatically chamber the next round after firing. Synonymous with semi-automatic in common usage.

In modern parlance, automatic firearms are functionally machineguns — they continue firing as long as the trigger is held and ammunition is available. Historically the term referred to auto-loading semi-automatic handguns.

A measure of a projectile's ability to overcome air resistance in flight, directly influencing speed, trajectory, and retained energy. A higher BC indicates better aerodynamic efficiency for long-range performance.

The study of the motion, behavior, and effects of projectiles in flight — encompassing internal, external, and terminal ballistics from ignition to impact.

A curved, detachable magazine typically used in AK-47-platform rifles. The distinctive curved shape allows for higher capacity while facilitating smoother feeding of rounds.

The cylindrical component of a firearm through which a bullet is fired, featuring spiral grooves (rifling) that impart spin to stabilize the projectile. Barrel length directly affects velocity and range.

A metal clamp or ring that secures the barrel of a rifle to the stock, found in older or military-style firearms. Maintains structural alignment and contributes to overall stability.

A fastening component that secures the barrel to the upper receiver (particularly in AR-15 rifles) and provides a mounting point for handguards and accessories.

A small, spherical sight at the front of a shotgun barrel serving as a visual aid for aiming — ideal for fast-moving shots in hunting or trap shooting.

A solid block of metal (typically aluminum or steel) that is machined into a specific component. Billet construction is known for strength and precision — carved from a single piece rather than forged or cast.

A specialized trigger that fires a round on both the pull and release, effectively doubling the rate of fire without converting the firearm to fully automatic.

A traditional firearm propellant composed of potassium nitrate, charcoal, and sulfur. Produces significant smoke and residue — less efficient and dirtier than modern smokeless powder.

A simple operating mechanism where expanding gas pushes the slide or bolt rearward to cycle the action. Common in semi-automatic pistols and submachine guns.

A metal treatment process providing a thin protective layer against rust and corrosion while giving the metal a dark blue-black finish, through controlled oxidation of the steel surface.

A bullet design where the rear tapers to a point, resembling a boat hull. The aerodynamic shape reduces drag and improves accuracy at long distances.

The mechanical component that moves back and forth to load, chamber, and eject cartridges. Locks the cartridge in place for proper ignition and cycling.

A firearm where the shooter manually operates a bolt to chamber a round, eject the spent casing, and reset the firing mechanism. Known for reliability and precision in hunting, long-range shooting, and sniper applications.

A critical assembly in AR-style rifles responsible for cycling the action, chambering rounds, and ejecting spent casings. Includes the bolt, firing pin, and extractor.

A mechanism that locks the bolt in the rear position after the last round is fired, allowing the shooter to quickly reload and confirm an empty magazine.

The interior of a firearm's barrel through which the bullet travels. Can be smooth or rifled — rifling consists of spiral grooves that impart spin for improved accuracy and stability.

A flexible, pull-through cleaning tool that quickly cleans the inside of a firearm's barrel. Features integrated brushes and cloth to remove residue and fouling without traditional rods and patches.

A tool or method used to align a firearm's barrel with its sights or optic before live firing, reducing the amount of ammunition needed to zero the firearm.

The outer shell of a cartridge housing the primer, powder, and bullet. Known for durability and corrosion resistance, brass casings can be reloaded and reused multiple times.

A firearm where the barrel is hinged and can be "broken" open to expose the chamber for manual loading and unloading. Common in shotguns and some rifles and pistols.

The rear part of a firearm's barrel where ammunition is loaded and fired. Modern breech mechanisms securely close to contain the pressure from a fired cartridge.

Shotgun ammunition containing multiple large pellets, used for hunting larger game like deer or for self-defense. Pellets spread out in a pattern increasing hit probability at close to medium range.

A component in semi-automatic and automatic rifles (like the AR-15) that absorbs recoil and controls cycling of the bolt carrier group, working with the buffer spring to manage rearward motion after firing.

Also called a receiver extension — a cylindrical housing in AR-style rifles containing the buffer and buffer spring. Also provides a mounting point for the rifle's stock.

A firearm chosen specifically for emergency evacuation, survival, or self-defense situations — typically reliable, lightweight, and versatile.

Large quantities of ammunition sold together at lower cost per round. Popular among shooters for range practice, training, or stockpiling.

The projectile fired from a firearm — a component of an ammunition cartridge. Traditionally made of lead, but can be built from any suitably dense or durable material.

The bottom portion of a bullet, opposite the tip. Design — flat, boat-tail, or hollow — affects aerodynamics, stability, and performance in flight.

The mass of a bullet, measured in grains, affecting velocity, trajectory, and impact. Heavier bullets retain energy at longer distances; lighter bullets travel faster but lose energy more quickly.

The rear part of the stock that rests against the shooter's shoulder when firing. Provides stability and helps absorb recoil.

A protective cover at the rear end of a rifle or shotgun stock providing a shoulder contact surface. Absorbs recoil and can be made of rubber, metal, or plastic for enhanced comfort during firing.

The internal diameter of a firearm's barrel or the diameter of the bullet it fires, measured in inches or millimeters. Determines size, power, and ammunition compatibility.

A precision measuring tool used to gauge distances between objects. Especially useful for measuring small dimensions like barrel inner diameters, case lengths, and bullet diameters.

Slang term for a sound suppressor, based on the cylindrical, can-like appearance of most suppressors.

A groove or series of grooves around the bullet or case of a cartridge, used to crimp the bullet securely in place or reduce friction when fired. Can also control bullet expansion or fragmentation on impact.

The tilt or angle of a firearm away from perfectly vertical when aiming or shooting. Improper cant can cause the bullet's trajectory to deviate from the intended target, especially at long range.

A mounting system where an accessory (like a scope) is supported by a bracket extending forward from its attachment point, allowing better weight distribution and flexibility in optic positioning.

A lightweight, compact rifle with a shorter barrel than a standard rifle, designed for improved handling and maneuverability. Popular for tactical use, home defense, and some hunting applications.

A shorter barrel length (typically around 16 inches) and corresponding gas system configuration in the AR-15 platform. Gas port positioned closer to the chamber for faster cycling — ideal for close-quarters applications.

Shortening a brass casing to a uniform length after firing and resizing. Ensures consistent chambering and safety when reloading, as repeated firings can stretch brass.

The cylindrical shell holding the bullet, gunpowder, and primer together as a complete cartridge. After firing, the casing is ejected from the firearm.

A type of ammunition with the primer located in the center of the cartridge base. Used in most modern rifle and handgun cartridges — more reliable and capable of handling higher pressures than rimfire.

The part of the barrel or frame where a cartridge is loaded and held in place before firing. Precisely machined to match specific cartridge dimensions for proper fit and safe operation.

The process of cutting or beveling sharp edges at a 45-degree angle to create a smoother transition between surfaces. Applied to barrel edges, chambers, and cylinders to ease reloading and reduce wear.

A manual device on a firearm (commonly the AR-15) used to pull the bolt carrier group rearward to chamber a round or clear the chamber. Critical for loading, resetting after firing, or handling malfunctions.

A pattern of small, raised ridges carved into a firearm's grip, stock, or forearm. Enhances grip and control, preventing slippage during shooting — especially in adverse conditions.

A constriction at the end of a shotgun barrel controlling the spread of the shot pattern. Types include full, modified, and improved cylinder — adjusting tightness for various ranges and applications.

A firearm is "clear" when the action is locked open, safety selector engaged, magazine emptied and removed, chamber is empty, and no ammunition is in the immediate vicinity. Designates the firearm as safe to handle.

Stands for Chief Law Enforcement Officer. A CLEO must be notified when purchasing a suppressor or other NFA-regulated item.

Often incorrectly used interchangeably with "magazine." A clip holds ammunition rounds together to be loaded into a magazine or cylinder — unlike a magazine, it is not spring-loaded.

Cleaner, Lubricant, and Protectant — a multi-purpose solution for firearm maintenance. Cleans fouling, lubricates moving parts, and provides a protective coating against rust and corrosion.

The alignment of a firearm's iron sights with an attached optic (like a red dot sight), allowing both sighting systems to be used simultaneously. Provides redundancy if the optic fails.

The act of pulling back the hammer to its locked rearward position, readying it to be dropped on the firing pin to detonate a cartridge.

Short for Communist Bloc — Eastern European and Soviet-aligned countries that produced standardized military firearms like the AK-47 and SKS. Characterized by rugged design, reliability, and common calibers like 7.62x39mm.

A muzzle device that reduces muzzle rise by redirecting propellant gas upward when a shot is fired, allowing better control and faster follow-up shots.

The act of lawfully carrying a firearm on one's person, hidden from plain sight. Also refers to firearms or tools specifically designed for easy concealment on a person's body.

A precision tool measuring the uniformity of a cartridge's alignment — specifically whether the bullet is seated evenly within the case — to improve accuracy, particularly in long-range shooting.

The rotating component of a revolver that holds multiple chambers for cartridges. As it rotates, each chamber aligns with the barrel and firing mechanism, allowing successive shots without reloading.

The process of removing sharp edges, rough spots, or excess material left behind after machining. Essential in firearms manufacturing for smooth operation and improved fit of components.

The process of removing the spent primer from a used cartridge case during reloading — an essential first step before inserting a new primer.

A reloading tool designed to push spent primers out through the primer pocket of cartridge cases — used in the initial stage of the reloading process.

A mechanism that safely lowers the hammer or firing pin from a cocked position without firing. Commonly found in double-action pistols to reduce the risk of accidental discharge.

A suppressor attachment method that screws directly onto a firearm's threaded barrel, providing a secure and stable fit for sound suppression.

A small device that breaks the mechanical connection between the trigger and the hammer/striker after firing, preventing the firearm from firing again until the trigger is fully released and pulled again.

A distinctive wooden foregrip on some AK-47 variants, characterized by its curved downward extension. Provides better control and stability — commonly seen on Eastern European or Vietnamese AK variants.

A trigger mechanism performing two functions in a single pull — cocking the hammer and releasing it to fire. Common in revolvers and some semi-automatic pistols.

A firearm malfunction where two cartridges attempt to enter the chamber simultaneously, causing a jam. Usually caused by issues with the magazine or extractor.

A magazine design with ammunition staggered in two vertical columns, allowing higher capacity than single-stack magazines without significantly increasing magazine length.

The technique of quickly firing two consecutive shots at a target with minimal time between them. Practiced in defensive shooting and competition to improve accuracy and speed under pressure.

The unintentional discharge of two rounds with a single trigger pull, caused by a malfunction or mechanical failure when the trigger mechanism or sear fails to reset properly between shots.

A machined, angled groove used to securely mount components like sights or scope bases onto a firearm. Provides a tight, friction-based fit that remains stable under recoil and use.

A measurement used in shotgun ammunition representing the power of modern smokeless powder loads compared to older black powder loads, giving shooters a way to gauge relative performance.

How far a round falls vertically due to gravity during flight. Higher velocity rounds experience less drop and require less vertical adjustment to hit an intended target.

A cylindrical-shaped magazine storing rounds in a spiral around the center, facing the barrel. Used in light machine guns and submachine guns for high-capacity operation.

Pulling the trigger on an unloaded firearm for training and practice to improve trigger control. Note: can cause wear on some rimfire designs over time.

A cartridge that fails to fire when the primer is struck, often due to a defective primer or improper storage. Requires the shooter to safely clear the misfired round before continuing.

A non-functional replica cartridge used for training, practice, or testing firearm mechanics without risk of firing. Lacks gunpowder and an active primer.

A protective component (commonly on AR-15s) that shields the ejection port from dirt, dust, and debris when not in use. Automatically opens when the firearm is fired.

The maximum distance at which a firearm can accurately and reliably hit a target while maintaining sufficient power for the intended result. Varies based on firearm, ammunition, and environmental conditions.

The process of expelling a spent cartridge casing from the chamber after firing. Performed by the ejector mechanism and critical for proper cycling of semi-automatic and automatic firearms.

The process of manually inserting a cartridge directly into the chamber through the ejection port, bypassing the magazine. Used when a quick reload is needed in semi-automatic firearms.

A component that grips the rim of a spent cartridge and pulls it out of the chamber after firing. Works with the ejector to remove the spent casing and prepare the firearm for the next round.

The maximum distance a bullet can travel under ideal conditions, beyond which accuracy, energy, and control are severely diminished. Typically much farther than effective range.

The distance between a shooter's eye and an optic's eyepiece at which a full, clear image is visible. Proper eye relief ensures comfort and safety, preventing injury from recoil while maintaining a clear sight picture.

The collection of internal components — typically trigger, hammer, and sear — that work together to initiate the firing sequence and control whether the firearm operates in semi-automatic, burst, or fully automatic modes.

A small, rod-like component that strikes the primer when the trigger is pulled, igniting the gunpowder and firing the round. Converts the mechanical action of the trigger into energy needed to discharge the bullet.

A specific muted brown or tan color finish used on firearms and tactical gear to blend with desert or arid environments. Popular for its camouflage properties and non-reflective matte appearance.

A trigger whose face — the forward surface the index finger applies pressure to — is flat or perpendicular to the receiver, as opposed to a curved trigger face.

The bottom portion of a magazine that retains the magazine spring and follower. Also called a baseplate — often the point where basepads or extensions attach.

The portion of a magazine that rests on the magazine spring and directly contacts the ammunition. Ensures consistent spring tension for reliable feeding into the action.

An accessory attached to the underside of a rifle's handguard, providing a more secure and comfortable grip for the support hand. Improves control and stability during rapid or sustained fire.

Also known as the forearm or handguard — the part of a firearm beneath the barrel providing a gripping surface for the support hand. Protects against barrel heat and may feature rails for accessories.

A small button on a firearm (most commonly the AR-15/M-16) allowing a shooter to manually push the bolt forward into the locked position. Developed in the 1960s in response to early M-16 reliability issues in Vietnam.

The buildup of residue — carbon, lead, copper, or powder — inside a firearm's barrel and action from firing. Reduces accuracy, reliability, and performance over time without regular cleaning.

Ammunition designed to break apart upon impact with a hard surface, reducing the risk of ricochets or over-penetration. Used in training and close-quarter environments for safety.

A bullet with a soft lead core encased in a harder metal shell (typically copper). Maintains shape upon impact, improving penetration and reducing barrel fouling compared to unjacketed bullets.

The buttstock, forearm (handguard), or pistol grip of a firearm — the external components a shooter handles and holds.

The first semi-automatic firearm adopted by the US Military. Chambered in .30-06, renowned for its power and reliability during World War II and the Korean War.

Controls gas flow from the barrel to cycle the action in a direct impingement AR-15. Affects recoil, reliability, and compatibility with suppressors or specific ammunition.

A small hole in the barrel of an AR-15 that directs propellant gas into the gas system, enabling cycling of the action for reliable semi-automatic fire.

A critical component in a direct impingement AR-15 that channels gas from the gas block to the bolt carrier group to cycle the action.

A measurement describing the bore size of a shotgun, based on how many lead balls of that diameter would weigh one pound. Smaller numbers indicate larger bores — a 12-gauge is larger than a 20-gauge.

The unit of measurement for bullet weight (abbreviated gr). Affects velocity, recoil, and performance for different shooting applications.

The pattern of bullet impacts on a target, indicating accuracy and consistency based on shooter skill, firearm precision, and ammunition quality.

In modern parlance, smokeless powder — powdered nitrocellulose with additives to reduce flash and increase stability. Rapidly oxidizes when ignited by a primer, and expanding gases propel a bullet down the barrel.

The craft and practice of repairing, modifying, customizing, and maintaining firearms. Gunsmiths perform tasks such as barrel threading, trigger adjustments, stock refinishing, and creating custom builds.

The metal part that strikes the firing pin or percussion cap to ignite the propellant and fire the bullet.

Firearms with a concealed hammer. The term is normally reserved for revolvers designed for concealed carry, where a protruding hammer can snag on clothing when drawing from a holster.

A protective component surrounding the barrel providing a safe gripping surface for the support hand. Shields from barrel heat and often features rails or mounting points for accessories.

The precise distance between a firearm's breech face and a cartridge's shoulder or base when fully chambered. Proper headspace is critical for safe and reliable operation — incorrect spacing can cause dangerous pressure issues.

Ammunition featuring bullets with a hollowed-out tip designed to expand on impact, delivering maximum stopping power and controlled penetration for self-defense and hunting.

A sound suppression system permanently built into a firearm's barrel, offering enhanced noise reduction, improved balance, and a streamlined design compared to detachable suppressors.

Analog aiming devices on a firearm. Traditionally constructed from metal — though some modern firearms like the Glock have polymer iron sights. Provide backup or primary aiming without batteries or optics.

A shooting technique where the shooter's arms and chest form an isosceles triangle — both arms extended equally toward the target. One of the two primary two-handed pistol stances alongside the Weaver stance.

A holster style worn inside the waistband of pants, keeping the gun closer to the body and less visible under clothing. Favored for concealed carry.

A hollow-tipped bullet covered by a metal jacket designed to expand upon impact. Expansion increases stopping power while reducing the risk of over-penetration — ideal for self-defense and hunting.

A bullet with a soft lead tip exposed at the nose and encased in a harder metal jacket. Allows controlled expansion on impact, balancing deep penetration and stopping power.

A lightweight, modular rail system using a keyhole-shaped slot design to attach accessories like grips, lights, and bipods securely and in a customizable setup.

A compact, short-barreled variant of the AK-series rifles — commonly referring to the AKS-74U. Known for its lightweight design and maneuverability in military and law enforcement applications.

A firearm using a lever near the trigger guard to cycle the action, chamber a round, and eject the spent casing. Iconic design associated with the Old West; still popular for hunting and sport shooting.

The straight, unobstructed path between an observer's eye and a specific object or point. Used in optics and navigation to ensure clear visual alignment.

A firearm with an extended barrel — such as a rifle or shotgun — designed to be fired from the shoulder for greater accuracy and range compared to handguns.

A group of parts necessary to complete a stripped AR-15 lower receiver. Includes a lower parts kit, pistol grip, receiver extension (buffer tube), and buttstock.

All the small parts necessary to render a stripped AR-15 lower receiver functional — excluding the pistol grip, stock, buffer tube, buffer spring, and buffer.

A rifle scope with variable magnification, typically 1x to 6x or 10x. Ideal for both close-quarters and mid-range shooting, offering quick target acquisition and enhanced precision at higher magnifications.

.22 LR (Long Rifle) — a popular rimfire cartridge known for low recoil, affordability, and versatility. Ideal for target shooting, training, small game hunting, and plinking.

A modular firearm rail system developed by Magpul, featuring direct-attachment slots for a secure, lightweight, and customizable mounting solution for accessories.

A U.S. military battle rifle introduced in the 1950s, chambered in 7.62x51mm NATO. Capable of semi-automatic and fully automatic fire. Replaced by the M16 as standard issue, but still used in designated marksman roles.

The civilian version of the military M14 rifle — semi-automatic and chambered in 7.62x51mm NATO (.308 Winchester). Popular for its reliability, accuracy, and classic design in target shooting, hunting, and competition.

A spring-loaded container that holds ammunition and feeds it into the receiver. Often incorrectly called a "clip" — the key distinction is that a magazine is spring-loaded.

Derived from the French term for extra-large wine bottles — magnum rounds are extra-powerful cartridges offering increased velocity, energy, or both compared to standard loadings.

The spring that powers the hammer or striker in a firearm to strike the primer and detonate a round.

Firearms, components, or ammunition manufactured to the highest precision and quality standards for superior accuracy and performance — designed for competitive shooting under demanding conditions.

A precision measuring tool used to accurately measure small dimensions such as barrel thickness, chamber dimensions, or bullet diameter. Essential for gunsmithing and reloading to ensure precise tolerances.

Short for military specification — standards set by the U.S. military for design, performance, and durability. In firearms, mil-spec indicates a product meets rigorous military criteria for reliability and compatibility.

A unit of angular measurement equal to 1/60th of a degree. In shooting, 1 MOA ≈ 1 inch at 100 yards — growing proportionally with distance. A "1 MOA rifle" shoots within a 1-inch group at 100 yards. Also used for scope adjustments.

A line of lightweight, durable firearm accessories from Magpul offering enhanced ergonomics and modularity for grips, stocks, handguards, and more.

Anything mounted on the end of a barrel that affects the firearm's performance or signature. Includes flash hiders, compensators, muzzle brakes, thread protectors, and sound suppressors.

Also called muzzle flip — the upward movement of a firearm's barrel when a shot is fired, caused by recoil forces. Affects accuracy during rapid fire by moving sights off target, requiring realignment for follow-up shots.

NATO ammunition refers to standardized cartridges used by NATO member countries to ensure cross-compatibility across firearms and military equipment. Common rounds include 5.56x45mm and 9x19mm.

A gear color known for its earthy green tone, offering effective camouflage and a classic military-inspired aesthetic.

Projectiles with a small opening at the tip created during manufacturing to ensure uniform distribution of core material for improved accuracy. Despite the hollow tip, designed for precision shooting rather than expansion — popular in long-range and sniper applications.

A holster style worn on the outside of a belt or pants, allowing easier access and quicker draw. Popular for open carry or range use.

A firearm combining the compactness of a carbine with pistol-caliber ammunition like 9mm or .45 ACP. Popular for home defense, competition, and training — offering reduced recoil and pistol magazine compatibility.

A standardized mounting platform with ridges and slots used to attach accessories like optics, lights, and grips. Allows secure, adjustable placement for versatile and modular setups.

The compact barrel length and gas system of an AR-style firearm, typically under 10.5 inches. Designed for AR pistols or short-barreled rifles (SBRs) to enhance maneuverability.

A pointed-nose bullet with a soft, exposed lead core at the tip. Offers better aerodynamics for accuracy and range — upon impact the soft tip expands for controlled penetration and stopping power. Useful for hunting.

A small, sensitive component in a firearm cartridge that ignites the gunpowder when struck by the firing pin. Located at the base of the cartridge — comes in boxer or berdan designs.

The process of preparing a cartridge by adding a primer — the component responsible for igniting the gunpowder when struck by the firing pin. A crucial step in ammunition manufacturing and reloading.

The part of a cartridge fired from a firearm — typically a bullet or shot — designed to travel toward a target with precision and velocity.

A firearm mechanism where the shooter manually slides the forend back and forth to eject a spent cartridge and chamber a new one. Found mainly in shotguns — known for reliability and ability to handle a wide variety of ammunition.

A system allowing accessories like slings, optics, or suppressors to be easily attached and removed from a firearm without tools. Enhances versatility and convenience for adapting setups to different applications.

Often called "kick" — the backward force exerted on a firearm when discharged, caused by propellant gases propelling the projectile forward. Managing recoil is essential for maintaining accuracy and shooter comfort.

A precision tool used to reshape, resize, and prepare spent cartridge cases for reloading. Types include resizing, decapping, and seating dies — each performing a specific function.

A type of ammunition where the primer compound is located within the rim of the cartridge base. When struck by the firing pin, the rim ignites the primer. Common in .22 LR — ideal for smaller calibers due to lightweight, low cost, and simplicity.

Firearm safeties prevent a gun from firing while engaged — a critical feature for safe handling, storage, and transport.

A mechanism allowing the user to engage or disengage the safety, preventing accidental discharge by blocking the trigger or firing mechanism. Toggles between "safe" and "fire" modes — may include burst or automatic settings.

A rifle with a barrel length under 16 inches, regulated by the ATF under the National Firearms Act (NFA). Requires a tax stamp for legal civilian ownership.

Firearms that automatically load the next round into the chamber after a shot is fired. Differ from fully automatic weapons in that the trigger must be pulled each time to fire.

A small, curved retaining spring in AK-style firearms that secures the hammer and trigger pins within the receiver, preventing shifting during operation and ensuring reliable fire control group functionality.

A trigger mechanism performing only one function — releasing the hammer or striker. In non-semi-automatic models, requires manually cocking the hammer before each shot.

A trigger mechanism with a consistent, smooth pull and no noticeable take-up or slack before the break. The shot releases immediately when the required pressure is applied. Favored for precision shooting and tactical applications.

The upper portion of an automatic pistol that moves back and forth during recoil. Houses the barrel, firing pin, extractor, and guide rod.

A handgun with a short barrel (typically 2 inches or less), designed for concealment and close-range use. Compact size makes it ideal for concealed carry, though shorter barrel results in lower accuracy and muzzle velocity.

Traditionally, the part of a firearm that the barrel and lock are attached to. In modern terms, it refers to the rear portion a shooter stabilizes against their shoulder when firing.

A firearm ignition system using an internal striker rather than a hammer to strike the primer. Provides a consistent trigger pull and enhanced reliability — common in modern handguns like Glocks.

The portion of an AR-15 that the barrel attaches to. A stripped upper lacks any functional components — no barrel, bolt carrier group, dust cover, or sights.

Ammunition designed to travel below the speed of sound (typically under 1,125 fps). Reduces the loud sonic crack associated with supersonic rounds — ideal for use with suppressors for quieter operation.

A brand of binary explosive targets made from ammonium nitrate and aluminum powder that detonates upon impact from a high-velocity bullet. Used in shooting sports for long-range target practice, creating a visible explosion when hit.

Federally required approval and fee issued by the ATF for purchasing and owning NFA-regulated items such as suppressors, short-barreled rifles, and machine guns. As of January 1, 2026, the $200 tax on suppressors has been eliminated — though the ATF Form 4 approval process remains required.

The mechanism a shooter actuates to drop the hammer or striker onto a cartridge's primer to fire the weapon.

A small but essential component in a firearm's lower receiver that secures the trigger assembly in place, ensuring proper function and stability during operation.

A firearm component (especially in AK-style rifles) that reinforces the receiver and provides a mounting point for the barrel and other essential parts.

A trigger system featuring a light initial take-up phase followed by a distinct second stage, allowing for greater control and precision before the shot breaks. Popular in precision and competition rifles.

An AR-15 Upper Parts Kit includes a charging handle, dust cover, and forward assist — the components needed to complete a stripped upper receiver's external functionality.

The top half of an AR-15 rifle that houses the barrel, bolt carrier group, charging handle, gas block, and handguard. The upper and lower receivers together form the complete rifle.

An accessory attached to the underside of a firearm's forend, providing a perpendicular handle for the support hand. Enhances control, stability, and maneuverability — especially during rapid firing or with heavier firearms.

A bullet with a flat nose designed for target shooting, creating clean, round holes in paper targets for easier scoring. Commonly used in revolvers — typically soft lead for lower recoil and accuracy at short ranges.

An alternative optics mounting rail system visually similar to the standard Picatinny rail, but not compatible with it. Generally considered obsolete, having been largely replaced by the Picatinny standard.

A two-handed pistol shooting stance where the shooter slightly blades themselves to the target, pushing outward with a straight shooting arm while pulling rearward with a bent support arm. Still used today but largely overshadowed by the Isosceles stance.

The horizontal adjustment of a firearm's sights to compensate for wind or other factors causing the bullet to drift left or right during flight. Also describes the lateral deviation of a projectile due to wind.