Letter B

The Definition of Ballistic Fingerprint

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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.


19 Other Firearms Definitions You Need To Know


Sight Alignment

The manner in which the sights are lined up properly in front of the shooter's eye, to form a straight path to the target.

Slug

More correctly a "rifled slug" or "shotgun slug." An individual cylindrical projectile designed to be discharged from a shotgun. The term is often incorrectly used to mean a Bullet.

Pitch

The angle of the butt of a gun in relation to the line of sight. Pitch is measured by resting the gun with its butt flat on a floor, the top of the receiver against a wall and its muzzle pointing up. The distance of the muzzle from the wall is the gun's pitch down.

Trigger Guard

Usually a circular or oval band of metal, horn or plastic that goes around the trigger to provide both protection and safety in shooting circumstances. The shooter's finger should never be within the trigger guard unless the sights are on target and the shooter has made the decision to fire.

BB

A type of steel round shot fired from air rifles. The name originated from the size of steel balls used in a shotgun of the same size (.177 caliber). In a 12 guage shotgun shell using BB size shot, there will be typically 90 BBs in a shell

FOPA

Firearm Owners' Protection Act of 1986. It is a United States federal law that revised many provisions of the Gun Control Act of 1968. It bans civilian ownership of machine guns manufactured after May 19, 1986. Firearms made and registered before that date are not affected. The law limits the Bureau of Alcohol, Tobacco and Firearms from inspecting gun dealers more than once a year, with follow-up inspections allowed only The law also specifically forbids the government from creating a national registry of gun ownership.

Shell Casing

A hollow, piece of metal (or plastic in the case of a shotgun shell) that is closed on one end except for a small hole which holds a primer. The open end holds the bullet. The hollow portion holds the powder. Together the assembled unit is called a cartridge.

Wad

A felt, paper, cardboard or plastic disk that is used in a shotshell. Also in muzzle loading, a piece of cloth used to seal the bullet in the barrel. It's purpose and function is the same as a shotgun wad.

Sling

A long strip of leather, plastic, or nylon which is fastened at the fore and rear of the gun for the easy carry of long guns.

Glock Auto Pistol

A type of .45 caliber ammunition designed in 2002 by Ernest Durham for use in the Glock Model 37.

Slide Lock

A slang term for slide catch.

Bluing

Also spelled blueing. A passivation process in which steel is partially protected against rust, and is named after the blue-black appearance of the resulting protective finish. True gun bluing is an electrochemical conversion coating resulting from an oxidizing chemical reaction with iron on the surface selectively forming magnetite (Fe3O4), the black oxide of iron, which occupies the same volume as metallic iron. Bluing is most commonly used by gun manufacturers, gunsmiths and gun owners to improve the cosmetic appearance of, and provide a measure of corrosion resistance to, their firearms.

Holdopen Toplever

A catch built into the receiver of a break-open gun to keep the toplever in its extreme right position when the barrels are removed. This device makes it slightly easier to remount the barrels. As the barrels are mounted and the breech closed, the barrels contact some kind of release pin (marked with the arrow) and the toplever automatically returns to the center locked position. Because, however, it requires a separate act to find and to depress this tiny tab to re-center the toplever on a broken-down gun, this feature may be irritating when trying to put a gun away in its case.

Trigger Pull Weight

The ammount pressure needed (measured in pounds) for the trigger finger must put on the trigger before the gun will fire. Trigger pull weight is measured by the number of pounds and ounces of pressure required to pull the trigger past the break.

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.

Frangible

A bullet that is designed to disintegrate into tiny particles upon impact to minimize their penetration for reasons of range safety, to limit environmental impact, or to limit the danger behind the intended target. Examples are the Glaser Safety Slug and the breaching round.

Gauge

System of measurement for the internal bore diameter of a smooth-bore firearm based on the diameter of each of that number of spherical lead balls whose total weight equals one pound. The internal diameter of a 12 gauge shotgun barrel is therefore equal to the diameter of a lead ball weighing 1/12 pound, which happens to be .729" (Or in British: Bore.) The Gauge/Bore system is also used, by convention, to describe the internal barrel diameter of large-bore, 19th century, English, single-shot and double-barrel rifles.

Cross Dominant

This means a shooter who is right-handed but left-eyed, or left-handed and right-eyed.

Kick

Slang for Recoil.