Letter B

The Definition of Bore Diameter

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Bore Diameter

The measurement from one side of the bore to the other. In a rifled barrel this means measurement of the bore before the rifling grooves are cut.


19 Other Firearms Definitions You Need To Know


Airsoft (Air Soft)

A type of airgun that shoots spherical non-metallic pellets.

Projectile

A bullet or shot in flight after discharge from a firearm.

Headstamp

Markings impressed into the base of a cartridge case, normally identifying the maker's name, the cartridge calibre designation, and sometimes the date.

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.

Cheekpiece

A broad, flat, raised area on the side of a buttstock.

Improved Cartridge

A wildcat cartridge that is created by straightening out the sides of an existing case and making a sharper shoulder to maximize powder space. Frequently the neck length and shoulder position are altered as well. The caliber is NOT changed in the process.

Trigger Break

The point at which the trigger allows the hammer to fall, or releases the striker, so that the shot fires. The ideal trigger break is sudden and definite. "Like a glass rod" is the cliche term shooters use to describe the ideal crisp, clean break.

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.

Musketoon

A musket shortened for cavalry use.

HMR

Abbreviation for Hornady Magnum Rimfire.

BUG

Abbreviation for 'Back Up Gun'

Machine Pistol

A handgun-style fully automatic or burst-mode firearm.
A machine pistol is not the same thing as a Submachine Gun

External Safety

A safety lever or button found on the outer surfaces of the firearm and is accessible to the user. Enabling the external safety should prevent accidental pulling of the trigger. However, the best safety is always you.

Zeroing

The act of setting up a telescopic or other sighting system so that the point of impact of a bullet matches the sights at a specified distance.

Mauser Action

The premier bolt action, whose design by Paul Mauser coalesced in 1898, and from which were derived the Springfield 1903, the Winchester Model 70 and many others.

Cant

To tilt a gun to one side or the other, complicating sighting considerably. Can cause material loss of accuracy, particularly with a rifle at longer ranges. Some better long range target rifles are equipped with Spirit Level sights to help control canting.

Electronic Hearing Protection

Ear muff or ear plug hearing protection that have internal electronics that amplify human voices while excluding all noises louder than a given decibel rating. Electronic hearing protection is best used when shooting outdoors. When on an indoor range they have a tendency to pick up too much echo and other muffled sounds.

Pre-Travel

Some triggers can be pulled slightly backwards before the shooter can feel any tension and before the hammer or striker begins to retract. Pre-travel is any movement of the trigger that begins before the trigger starts to engage.

Slide Catch

Sometimes also known as a slide lock, slide release or slide lever. On a semi-autmatic gun, the lever or catch that holds the slide open (after the last round is fired or when racking an empty gun). Typically they are located on the left side of the frame about mide barrel. Some of the newer semi-automatic pistols have an internal slide lock. Even though on pistols with an external slide catch, you can push down on the lever to release the slide, it should never be used in such a manner. The proper way to release the slide is to rack the slide.