Letter Z

The Definition of Zero

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Zero

A firearm is said to be "zeroed in" when its sights have been adjusted so that the bullet will hit the center of the target when the sights are properly aligned upon the center of the target. The farthest distance from a firearm at which the bullet's path and the point of aim coincide. This term is also used to mean the process of insuring that the sights of a firearm are properly aligned so that where they indicate the bullet will strike is in fact where it strikes.


19 Other Firearms Definitions You Need To Know


Firing Pin

A needle like metal part of a modern firearm that gives a vigorous strike to the primer initiating the firing of the cartridge.

Primer

A small metal cup that contains a tiny explosive charge that is sensitive to impact. A primer is placed in the base of a shell casing to ignite the powder of the completed cartridge. It is detonated by the striking of a firing pin in the firearm.

Comb

The top of a gun's stock, where a shooter rests his cheek when mounting a gun. As it is the top of the stock that determines the position of one's eye, and one's eye is the rear sight on a shotgun, the position of the comb is very important in determining the proper fit of a shotgun.

Out of Battery

A semi-automatic is said to be out of battery when the slide fails to come all the way forward again after the gun has fired. This condition can be created by a misfeed, a dirty gun, weak springs, the shooter's thumbs brushing against the slide, riding the slide, or any of several other causes.

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.

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.

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.

Pan

The small dished container located on the side or top of a matchlock, wheel-lock or flintlock forearm used to hold the priming powder charge.

Co-Witness Sighting

Co-Witness Sighting is the use of any iron sight mounted onto a rifle that is fitted with an optical sight as a primary sighting system. They come in two basic configurations, fixed or flip-up. The idea is that if you align your red dot and your iron sights you have a backup aiming system on the gun.

Igniting Charge

The charge used to ignite the propelling charge.

Standing Breech

The face of the action of a break-open firearm which houses the firing pins and receives the direct recoil of the fired round.

Speed Strip

A flat piece of rubber which holds revolver cartridges preparatory to loading them into the revolver's cylinder. Similar to a moon clip

Annulus

A tiny circular recess at the base of a cartridge case surrounding the primer pocket. Recoil from fired cartridges invariably impress a discernable ring on the breech or bolt face of a firearm, providing some evidence of the amount of use it has seen.

Trigger Scale

A specialized type of hanging scale designed to test trigger pull weight.

Shooting Sticks

A pair of slender and easily-carried wooden dowels or sticks, which when held, crossed, in the fingers of the left hand while also supporting the forend of a rifle, usually shooting offhand, provides somewhat enhanced stability for a more accurate shot.

Internal Safety

A safety which is placed within the gun and is not accessible to the user. Internal safeties are generally designed to prevent unintentional discharges when the gun is dropped or mishandled.

VCCLEA

Violent Crime Control and Law Enforcement Act of 1994. It is an act of Congress dealing with crime and law enforcement that became law in 1994. Of the sections of the bill, it included the Federal Assault Weapons Ban.

Erosion

The wearing away of a barrel's metal surface by a bullet or shot charge or by the heat of powder gases.

Snap Cap

An inert ammunition-shaped object, used in practice to simulate misfeeds and other malfunctions. Some folks also use them during dry fire practice to cushion the firing pin as it strikes.