Letter B

The Definition of Birdshot

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Birdshot

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"


19 Other Firearms Definitions You Need To Know


Buckshot

A type of shotgun ammunition that uses medium-sized to large-sized pellets of .24" in diameter or greater, designed to be discharged in quantity from a shotgun. Generally the larger the pellets, the fewer of them there are in casing.

Boresight (Bore Sight)

Crude adjustments made to an optical firearm sight, or iron sights, to align the firearm barrel and sights. This method is usually used to pre-align the sights, which makes zeroing (zero drop at XX distance) much faster.

Ghost-Ring Sight

A type of aperture rear sight with a large opening and a thin rim that seems to fade out when the shooter looks through it. Sometimes installed on rifles and shotguns intended for home defense or police use.

Drop Safety

A mechanical safety that prevents a gun from firing when it is unintentionally dropped.

Automatic

A type of firearm which, utilizing some of the recoil or some of the expanding-gas energy from the firing cartridge, cycles the action to eject the spent shell, to chamber a fresh one from a magazine, to cock the mainspring and to fire again. Such a firearm will fire continuously as long as the trigger is held back, until the magazine is empty. A machine gun. A firearm thus activated, but which shoots only one bullet with each separate pull of the trigger, while often erroneously referred to as "automatic" is properly termed Semi-Automatic.

Brass

The term used for the casing on modern rifle and pistol ammunition. It is usually made out of brass but can also be aluminum or steel. The casing on a shotgun shell is usually refered to as a hull

Single Action

An action type that when the trigger is pulled, the only thing the trigger does is drop the hammer (or striker). This applies to both revolvers, semi-automatic and automatic guns. On a single action revolver, the gun must be manually cocked before it can be fired. With semi-automatic and automatic guns that are single action, the only thing the trigger does is drop the hammer, striker or firing pin onto the cartridge. Then the firearm is cocked again when from the recoil of the fired round. A firearm that the gun is cocked and the hammer drops when the trigger is pulled is a double action gun.

Failure To Feed

A semi-automatic firearm malfunction in which the slide passes entirely over the fresh round, failing to pick it up to insert into the chamber as the slide returns to battery.

Direct Impingement

A type of gas operation for a firearm that directs gas from a fired cartridge directly to the bolt carrier or slide assembly to cycle the action.

Pellet (air gun)

Skirted projectiles used in pellet guns

Internal Trigger Lock

A internal locking device built into a firearm, usually operated with a key, to render it unable to be fired. A good example of a internal trigger lock are the ones found on the semi-automatic pistols manufactured by Bersa.

Machine Gun

A fully automatic firearm that rapidly fires multiple rifle-caliber shots with a single pull of the trigger.

Needle Gun

A needle gun is a bolt-action firearm (the first known type of bolt action rifle) that has a needle-like firing pin, which can pass through fully self-contained (paper) cartridge case to strike a percussion cap at the bullet base. The first experimental needle gun was designed by Jean Samuel Pauly, a Swiss gunsmith, in 1812. The first mass-produced needle gun was invented by the German gunsmith Johann Nicolaus von Dreyse, who, beginning in 1824, had conducted multiple experiments, and in 1836 produced the first viable breech loading gun model using a complete cartridge .

Soft Point

A metal jacketed bullet design in which the nose of the core of the bullet is exposed to ensure the expansion of the bullet upon impact. Often abbreviated "JSP" or "SP." They tend to expand more slowly than a Hollow Point bullet and are used where deeper penetration and expansion are needed.

Follower

A smooth, sometimes contoured plate, within a magazine, at the top of a spring, across which cartridges slide when being loaded into a chamber.

Sling

A strap, usually of leather or sturdy webbing, fitted to the fore and aft (usually) of a rifle as an aid to carrying over the shoulder and as an aid to holding the rifle steadily while aiming.

Trace

Visible disturbance in the air by a bullet. Typically this takes the form of image distortion that persists for a fraction of a second in the shape of an inverted V similar to that of a boat wake.

Twilight Sight

A rifle front sight with a extra-large, folding bead. Typically, in addition to the normal fine bead (which allows for more precision) the larger bead, while at a cost of potential accuracy, is more readily acquired in marginal light. Also called a Gloaming sight

Aperture Sight

Also known as peep sights, range from the ghost ring sight, whose thin ring blurs to near invisibility (hence ghost), to target aperture sights that use large disks or other occluders with pinhole-sized apertures. In general, the thicker the ring, the more precise the sight, and the thinner the ring, the faster the sight.