Letter B

The Definition of Breech Pressure

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Breech Pressure

The amount of rearward force exerted by the propellant gases on the bolt or breech of a firearm action or breech when a projectile is fired. The applied force has both magnitude and direction, making it a vector quantity. This is also known as Bolt Thrust on firearms that are Bolt Action


19 Other Firearms Definitions You Need To Know


Short Trigger

A trigger that doesn't have to travel very far before it reaches the break. In a 1911 semi-auto pistol, a short trigger is a different part than a long trigger, and (in addition to providing less motion) it features a shorter reach which may be of benefit to a small-handed shooter.

Butt

The rear end of a rifle or shotgun. (The portion that rests against the shoulder.)

Sleeved Barrels

An economical method of bringing new life to a damaged pair of barrels, regardless of their original method of jointing. The ribs are removed. The barrels are cut off 3" - 4" from the breech end and discarded. The bores of the remaining breech-end are reamed out oversize. New tubes are fitted down into the original breech section and filed down to fit flush. The original ribs are then replaced. Sleeving is considerably less expensive than building a completely new set of barrels. Much of the time required to build a set of barrels is concentrated in the fitting of the breech end to the receiver; this work is salvaged through sleeving. Sleeving can be recognized by a pair of circumferential lines around the barrels a few inches from the breech; the more invisible, the finer the job. A sleeved gun should always be identified as such amongst the proof marks, and if done in England must be properly reproofed. Photo Sleeving is not the same thing as Monoblocking.

Clip

A clip IS NOT a magazine. A clip is used to load a magazine.
A clip is a simple, disposable narrow spring-lined channel-rail that is used to store multiple rounds of ammunition together as a unit, ready for insertion into the magazine of a repeating firearm. This speeds up the process of loading and reloading the firearm as several rounds can be loaded at once, rather than one round being loaded at a time. The term clip commonly refers to a firearm magazine, though this usage is absolutely completely totaly 100% incorrect. In the correct usage, a clip is used to feed a magazine or revolving cylinder, while a magazine or a belt is used to load cartridges into the chamber of a firearm. in which cartridges are supplied for military weapons. The shooter positions the clip vertically above the firearm's magazine, then pressing down with the thumb, slides the cartridges from the clip and down into the magazine.

Double Triggers

On guns (mainly shotguns) that have two barrels, there is a trigger for each barrel that work independently from each other.

Belt Fed

A firearm, usually (but not always) a fully automatic rifle, that uses a ammunition on a belt rather than a magazine to store the rounds that will be loaded into the gun.

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.

Hollow-Point Bullet

A type of expanding bullet with a concavity in its nose to increase expansion on penetration of a solid target. Some hollow-point's are also designed to fragment as they expand. They are least likely to over-penetrate the target and harm an innocent bystander. Commonly used for self-defense.

Breech

The rear end of the barrel into which the cartridge is inserted

Sight Radius

The distance between the rear sight and the front sight. As a longer lever provides greater mechanical advantage, the greater the distance between the two sights, the more inherently accurate they will be.

Parallax

This occurs in telescopic sights when the primary image of the objective lens does not coincide with the reticle.Telescopic sights often have parallax adjustments to minimize this effect.

ACP

The abbreviation for Automatic Colt Pistol. It is commonly used to designate specific calibers, particularly those which were originally designed by John Moses Browning for the Colt Firearms Company which are a type of rimless pistol cartridge designed mainly for use in semi-automatic pistols. The most common ACP calibers are .25 ACP, .32 ACP, .380 ACP and .45 ACP.

BATFE

Abbreviation for the Bureau of Alcohol, Tobacco, Firearms and Explosives

Cold Clean Bore

The first shot from a rifle that has been cleaned, and not fired recently may go to a different point of impact, for the same point of aim than a rifle that has been fired recently. This first shot is referred to as a shot from a cold, clean, bore.

Firing Line

A line, either imaginary or marked, from which people shoot their firearms down range.

Stovepipe

Failure of a spent case to completely eject from a semi-automatic firearm. The case usually stands on end while lodged in the ejection port.

Repeater

A type of firearm capable of discharging multiple individual shots in sequence, fed from a magazine, via the operation a lever, bolt, slide or some other form of manual operation.

Patch Box

Covered compartment in the buttstock of a rifle used to carry patches or other small items.

Floor Plate

The detachable plate at the bottom of the cartridge magazine.