Anything that will safely stop a bullet and prevent it from hitting anything else after the target is struck.

Shooting Range Backstop
Shooting Range Backstop





















A handgun term. The rearmost surface of the grip. The rear of two gripstraps on a handgun, which lies beneath the heel of the hand when gripping the gun.

Handgun Backstrap
Handgun Backstrap


















Ball Ammunition

Originally a spherical projectile, now generally a fully jacketed bullet of cylindrical profile capped with a round nose.

Original Ball Ammunition Original Ball Ammunition                                                                  Modern Ball Ammunition Modern Ball Ammunition

Ballistic Fingerprint

A fired case has marks upon it that it picked up from the extractor, ejector, and breechface of the gun when the shot went off. A bullet fired through a rifled barrel also has rifling marks unique to the barrel that launched it. A record of these marks, when stored in a central database, is called a ballistic fingerprint. Some states require this record to be made by law, so that individual guns can be located from bullets or casings found at the scene of a crime.

Ballistic Fingerprint
Ballistic Fingerprint


The science of cartridge discharge and the bullet's flight. Internal ballistics deals with what happens inside of a firearm upon discharge. External ballistics is the study of a projectile's flight, and terminal ballistics is the study of the impact of a projectile.  science of projectiles. Interior ballistics deals with the propulsion and the motion of a projectile within a gun or firing device. Its problems include the ignition and burning of the propellant powder, the pressure produced by the expanding gases, the movement of the projectile through the bore, and the designing of the barrel to resist resulting stresses and strains.

Exterior ballistics is concerned with the motion of a projectile while in flight and includes the study not only of the flight path of bullets but also of bombs, rockets, and missiles. All projectiles traveling through the air are affected by wind, air resistance, and the force of gravity. These forces induce a curved path known as a trajectory. The trajectory varies with the weight and shape of the projectile, with its initial velocity, and with the angle at which it is fired. The general shape of a trajectory is that of a parabola. The total distance traveled by a projectile is known as its range.

Internal Ballistics - Ammunition Internal Ballistics - Ammunition   Terminal Ballistics Terminal Ballistics Bullet Flight Path Bullet Flight Path



The cylindrical metallic part of a gun which controls the initial direction of a projectile. A tube through which a bullet travels when a gun is fired

Gun Barrel (cut away)
Gun Barrel (cut away)



















[bat-uh-ree; French batuh-ree]

(In) Battery - A condition of a firearm where it is loaded, with the action closed, cocked and (with the possible exception of an engaged safety catch) ready to fire.


  1. Two or more pieces of artillery used for combined action.
  2. A tactical unit of artillery, usually consisting of six guns together with the artillerymen, equipment, etc., required to operate them.
  3. A parapet or fortification equipped with artillery.
Bayonet Lug

Bay·o·net Lug

(bā′ə-nĕt′, bā′ə-nĭt, -nĕt′ (lŭg)

A mounting point on a small arm that allows a bayonet or other accessory to be attached. A bayonet lug is a standard feature on most military muskets, rifles, and shotguns, and on some civilian longarms. It is intended for attaching a bayonet, which is typically a long spike or thrusting knife. The bayonet lug is the metal mount that either locks the bayonet onto the weapon or provides a base for the bayonet to rest against, so that when a bayonet thrust is made, the bayonet does not move or slip backwards.

Bayonet Lug
Bayonet Lug




















Beavertail pistol grip: the grip style used on the Colt 1911 handgun. A large piece of curved metal at the top of the grip which protects the user's hand from getting bitten by the hammer. It is nearly always the top part of the grip safety commonly found on many 1911-style pistols.

Beavertail on a 1911 style pistol
Beavertail on a 1911 style pistol


















Benchrest Shooting

noun bench·rest \ˈbench-ˌrest\

Benchrest shooting is a sport in which very accurate and precise rifles are shot at paper targets. The rifles ride on a front and rear rest, the rests may or may not be joined, depending on the rules of a particular competition. The rests sit on a table or bench, hence the name "benchrest. A shooting sport in which the competitors seek to place five or ten consecutive shots into the smallest possible group on a paper target at various ranges. All firing is done from an artificially supported shooting position. It is a severe test of the mechanical precision of both the small arm and its ammunition.

Benchrest Shooting
Benchrest Shooting




















On an outdoor shooting range, a large pile of dirt that functions as a backstop.

Berm for Target Shooting
Berm for Target Shooting


















Bevel Base

(bĕv′əl)   (bās)

Any bullet design in which there is a slight bevel (to facilitate cartridge reloading) between the base and the bearing surface proper. (Opposed to Plain Base)

Bevel Base Rifle BulletBevel Base Rifle BulletBevel Base Handgun BulletBevel Base Handgun Bullet


bi·ath·lon (bī-ăth′lən, -lŏn′)

A competition that combines events in cross-country skiing and rifle shooting. A shooting sport that combines both skiing and rifle shooting. It is the only shooting activity in the Winter Olympics. There is also a summer biathlon which involves running and shooting but it is not yet an Olympic event.

Biathlon Shooting
Biathlon Shooting















bi·pod (bī′pŏd′)

A stand having two legs, as for the support of an instrument or a weapon. A two legged support for the front end of a rifle to stabilize the gun while shooting.

Rifle with Bipod
Rifle with Bipod











Bird Shot

bird·shot (bûrd′shŏt′)

(Hunting) small pellets designed for shooting birds. Small lead shot for shotgun shells. A type of shotgun ammunition which uses very small pellets with individual projectiles of less than .24" in diameter designed to be discharged in quantity from the shotgun. The size of the shot is given as a number or letter--with the larger number the smaller the shot size. It is so named because it is most often used for hunting birds. The finest size generally used is #9 which is approximately .08" in diameter and the largest common size is #2 which is approximately .15"



















Black Powder

[¦blak ′pau̇d·ər]

The earliest type of firearms propellant that has generally been replaced by smokeless powder except for use in muzzleloaders and older breechloading guns that demand its lower pressure levels. An explosive mixture of saltpeter, charcoal, and sulfur, formerly used in firearms. An explosive propellant, which is obtained by carefully fragmenting and mixing potassium nitrate, charcoal, and sulfur in the proportions (by percentage weight) of 75:15:10.

Black powder is easily ignited and burns rapidly without air to form gases that are able to perform considerable mechanical work. It is one ofthe oldest explosives. No accurate date has been established for its invention.

Black Powder


















Blank Cartridge

blank′ car′tridge [blaŋk]  (kär′trĭj)

A gun cartridge with a charge of powder but no bullet. Ammunition which contains no projectile but which does contain a charge of low explosive, such as black powder, to produce a noise.

Blank Cartridge Blank Cartridge



A semi-automatic firearm whose breechblock and barrel are not mechanically locked together when fired. In such case the breechblock immediately begins to separate from the barrel upon firing. Blowback is used in comparatively low powered weapons, in which inertia of the breechblock, and cartridge wall adhesion against the chamber, are sufficient enough to retard opening until breech gas pressures have fallen to a safe level.

A type of action in an autoloading firearm where the breech is not locked. Rather, the recoil of the firing cartridge overcomes the inertia of a spring-loaded breechblock, forcing it back to cycle the action. A simple design, but limited to relatively low powered firearms---typically pistols of calibre .380ACP or less---or an impractically heavy breechblock would be required.

Gas BlowbackGas Blowback

blu·ing ˈblo͞oiNG/
  1. The chemical process of artificial oxidation (rusting) applied to gun parts so that the metal attains a dark blue or nearly black appearance.
  2. A controlled chemical rust process that produces a very dark, almost black, blue finish to the steel parts of a firearm which enhances the appearance and provides some protection from unwanted rust. Sometimes it can have a slight brownish undertone. The percentage of blue finish remaining on a gun can be a proxy for describing its condition.

Boat Tail


  1. A type of bullet, tapered at the rear in order to decrease turbulence in flight and increase accuracy. More prevalent in target rather than hunting bullets.
  2. A type of projectile that has a tapered base (rear end) that reduces the drag from the air as it travels to its target.


  1. The mechanism of some firearms that holds the cartridge in place during the firing process. It must be moved out of the way to load and unload the gun; this action may be manually performed by the shooter pulling back on an exterior knob called the bolt handle and then sending it forward again, or the action may be performed by other moving parts within the firearm. When the user must move the bolt manually, the firearm is called a bolt-action firearm.

2. A cylindrical shaft, controlled by an attached lever, which rotates a partial revolution engaging locking lugs in complementary recesses, contains an internal spring-loaded firing pin, and becomes the breech-block of a bolt-action firearm.

Bolt Action

[bohlt-ak-shuh n]

  • An action type, most frequently used on rifles, perfected by Peter Paul Mauser in 1898, whereby a cylindrical shaft, controlled by an attached lever, manually feeds a cartridge into the chamber, rotates a partial revolution engaging locking lugs in complementary recesses in the front receiver ring, allows firing by the fall of an internal spring-loaded pin, opening, extraction, re-cocking and ejection with the same lever in preparation for the next shot.
  • A type of firearm, almost always a rifle, in which an empty shell casing is removed from the firing chamber by the turning and retraction of a metal cylinder shaped mechanism called a bolt. A new, un-fired, cartridge is inserted and secured into the chamber by reversing the action of the bolt.
Bolt Stop
  • A displace-able flange, usually towards the rear of a bolt action firearm which in normal position, either detented or under spring tension, prevents the bolt from falling completely out the rear when cycling the action. It is readily moved aside by the bolt stop release to allow removal of the bolt for cleaning or disassembly.
Bolted Safety
  • A secondary catch on the safety, often seen on big-bore double rifles, designed to prevent its inadvertent disengagement by a careless gunbearer

[bawr, bohr]

  • The inside surface of a firearm's barrel. British term for Gauge
  • The hollow portion of a barrel through which the bullet travels during it's acceleration phase.
  • A smooth-bore firearm is one that does not have rifling on the barrel's internal surface.
  • A big-bore firearm is one that fires a large caliber.
  • A small-bore firearm is one that fires a small caliber.
Bore Diameter

[bawr, bohr]    [dahy-am-i-ter]

  • The diameter of the inside of the barrel after boring, but before rifling.
Bore Sight

[bawr-sahyt, bohr-]

  • A process by which sights are adjusted to converge on the same line as the bore. Accomplished by placing a rifle in a rest, sighting down the open bore on a prominent distant point at an appropriate range, then aligning the sights to superimpose on the same point. Alternatively, may be accomplished with a device known as a collimator. The process should conserve ammunition when sighting-in a rifle by approaching proper sight adjustment before actually firing the rifle with live ammunition.


  • A type of cartridge with a pronounced shoulder between the body of the case and the mouth---where the bullet diameter is noticeably less than the case diameter, allowing a larger powder capacity than would otherwise be possible in an altogether more cylindrical case, and to provide a datum point to establish correct headspace.


  • A cartridge case having a primer pocket with one central touchhole at the center bottom. A tiny anvil is built into the primer to provide a surface against which the detonating compound may be sharply pinched by the action of the firing pin. Most commonly used in the USA today. It is simple to remove the spent Boxer primer for re-loading the shell casing with a single, central, pin-shaped decapping punch.
  • A type of action (receiver) for a break-open gun where the lockwork is contained within a box-shaped housing. (see also: Sidelock). A boxlock is superior to a sidelock because although more metal needs to be removed from the action body, less wood needs be removed from the head of the stock---and wood is generally more vulnerable than metal. The Anson & Deeley boxlock, patented in 1875, the simplest, most reliable and most successful action design, is identified by two pins spanning the width of the action, one at the bottom rear and one slightly forward and higher, upon which the sears and hammers, respectively, rotate.
  • Black Powder Express. A cartridge "as powerful as an express train."

[bras, brahs]

  • An alloy of approximately 2 parts copper and 1 part zinc, which because of its combination of strength and ductility, is commonly used for making cartridge cases, which fit easily into the chamber of a firearm and then when discharged, expand to seal the breech. Also, slang for cartridge cases.
  • A slang term for an empty shell casing. Most shell casings are made of the metal alloy known as brass.

[noun breech; verb breech, brich]

  • The end of a barrel where the powder charge is ignited; the end closest to the shooter
  • That portion of the gun that contains the rear chamber portion of the barrel. The rearmost end of a barrel, closest to the shooter.
Breech Block


  • A moveable block of steel, sliding in a mortised raceway, or rotating on a hingepin, that seals the breech of a cartridge firearm and through which the firing pin passes to detonate the primer.
Breech Face
  • The flat, normally-vertically-oriented steel wall through which the firing pin passes and which supports the base of a cartridge when it is fired
  • That portion of the breech block which touches the cartridge when the breech is closed.
Breech Loading Gun Breechloader


  • A firearm that is loaded from the breech end of the barrel, usually with a cartridge (as opposed to a muzzle-loader).
  • A firearm in which the cartridge or shell is inserted or loaded into a chamber to the rear portion of a barrel.
Breech Opening
  • The open rear of the barrel through which cartridges are inserted into the chamber.  


  • A box of ammunition roughly equal in size and weight to a brick. Most often used to describe a 500-round container of 22 Long Rifle ammunition.


  • A small secondary plate, mounted behind and parallel to a sidelock gun's lockplate which supports the inside ends of the pins about which the moving parts rotate
Broadway Rib

[brawd-wey]   [rib]

  • Browning term for a particularly wide rib for their over & under target guns.


  • An oxidation process applied to the surface of raw steel, undertaken with acids, to produce a finish that resists further rusting, providing as you might expect a brownish color, allowing the pattern of damascus barrels to show through. Popular in the 19th century and with people today desirous of evoking that time.
Browning John Moses
  • The world's greatest firearms inventor. Born in Ogden, Utah. While he made some guns himself, normally, he licensed his designs to prominent manufacturers such as Colt, Fabrique National and Winchester. While Samuel Colt and Paul Mauser achieved fame basically as a result of one idea, John M. Browning produced dozens of the most successful firearms designs, including the Winchester 1885, 1886, 1892, 1894 and 1895 rifles; The Colt 1903, 1908, 1911 and Woodsman pistols; the Browning Auto-5 and Superposed shotguns; as well as the BAR, 1917 and M2 .50 calibre machine guns.
BT or Beavertail Forend
  • A broad forend, wrapping partially around the barrel(s) to give a more positive grip and to better protect the hand from hot barrels than does a splinter forend.
Buckhorn Sight

/ˈbʌkˌhɔːn/   [sahyt]  

  • A rear barrel iron sight, normally used on rifles, where the open-topped viewport is formed by a pair of symmetrical crescents. Rocky Mountain sight.
Bulino Engraving


  • Shallow, pictorial engraving designs, often of photographic quality, executed directly by hand onto the steel with a fine-pointed scribe called a burin, without the use of a chasing hammer. Also called banknote engraving. Often seen on high-grade, contemporary Italian shotguns.
Bull Barrel

[boo l]  [bar-uh l]

  • A general term for a large-diameter, heavy, rifle barrel, used for target or varmint shooting.
  • "Bull barrels" are barrels that are not tapered at all. These very heavy barrels, designed for extreme accuracy, are usually seen on target rifles.

noun, bul·let often attributive  (bo͝ol′ĭt)

A small piece of metal or another material that is shot out of a gun. A usually metal projectile in the shape of a pointed cylinder or a ball that is expelled from a firearm, especially a rifle or handgun.

Diagram of a Cartridge Diagram of a Cartridge                                                      Bullets Bullets

Bullet Mold
  • A hand tool, in the general shape of a pair of pliers, with a two-part cavity of specific dimension at the working end, into which is poured molten lead in order to cast a bullet for a specific firearm. Normally affixed with a sprue-cutter to trim the excess lead from the bullet.
Bullet Proof Vest
  • A popular but incorrect term for bullet resistant clothing.
Bullet Starter
  • A tool fitted with a concentric plunger used for starting a bullet on a balanced path into the bore of a rifle from the muzzle. Often used in conjunction with a false muzzle built for the specific rifle.
Bullet Trap
  • A type of backstop that catches the fired bullet and prevents it from exiting the area. Bullet traps are most commonly used on indoor ranges.
  • A rifle configuration in which the action and magazine are located behind the trigger. This makes the overall length of the firearm shorter than it otherwise would be.
Burgess Front Sight
  • An excellent easily retractable front sight blade, designed and built by gunsmith Tom Burgess.
Burgess Mounts
  • An excellent quick-detachable scope mounting system, designed and built by gunsmith Tom Burgess. Operated by turning locking levers a detented 90 degrees.


  • Burnish (v) - To smooth a (steel) surface to a mirror finish by firmly rubbing with a hard, polished steel tool, compressing unevenness in the surface.

Bushed Firing Pins
  • Circular steel fittings, about 1/2 inch in diameter, screwed into the breech face of a gun and through which the firing pins pass. Firing pin bushings allow the convenient replacement of broken firing pins. They also allow the renewal of an older gun where, over the decades, leakage of high-pressure gas from corrosive primers has eroded the breech face around the firing pins. In British: Disk-set strikers


  • The end of a gun stock; the part that rests on the shoulder when the gun is mounted.
  • A fixed-position shooting station for British-style driven bird shooting, often rock-lined and partially underground, providing some effect of a blind for the shooter (the Gun) and his loader.
  • The base of the grip on a handgun and the rearmost portion of the stock on a long gun that braces against the shoulder.


  • A plate made usually of metal and attached to the butt end of a gun stock

  • A plate made of some material harder than the wood of the buttstock, fitted to the end of same to protect it. It may be made of hardrubber, horn, plastic or steel. It may be shaped relatively flat like a Winchester "Shotgun" butt on a rifle, like a crescent, or with all manner of protruding appendages in the interest of achieving consistency of mounting position as in a Swiss or scheutzen buttplate. It may be finished smooth, checkered, striated or engraved.