Letter E

The Definition of Eye Relief

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Eye Relief

The distance that equates the exit pupil size of a rifle scope's ocular lens to the entrance pupil of the user, in order to achieve the largest, unvignetted view. This distance must be sufficient to ensure that the ocular rim of the scope does not lacerate the shooter's eyebrow upon recoil. And, the scope should be positioned so that eye relief is suitable when the rifle is comfortably mounted.


19 Other Firearms Definitions You Need To Know


Safe

A firearm is said to be on safe when its safety is engaged and off safe when it is ready to fire.

Polygonal Rifling

A type of gun barrel rifling where the traditional lands and grooves are replaced by "hills and valleys" in a rounded polygonal pattern, usually a hexagon or octagon. Polygons with a larger number of edges provide a better gas seal in relatively large diameter polygonally rifled bores.

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.

Hammer Bite

The action of an external hammer pinching or poking the web of the operator's shooting hand between the thumb and fore-finger when the gun is fired.

Howdah Pistol

Normally, a break-open, double-barrel, side-by-side pistol of large calibre, used by a maharaja when hunting tiger on the back of his elephant (in the howdah, the basket compartment in which he sits). The howdah pistol is the weapon of last resort in case the tiger tries to join him in the howdah.

Colt

A firearms manufacturer started by Samuel Colt in 1855. Colt is most famous for the revolvers they invented and built in the 1800's and the semi-automatic pistol model 1911 designed by John Moses Browning, and for being the first manufacturer of the AR-15 type rifles.

CCW

Abbreviation for Concealed Carry Weapon

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.

POA

Abbreviation for Point of Aim

Trigger Slap

An uncomfortable sensation caused by the trigger springing back into the shooter's trigger finger while firing.

Loaded Chamber Indicator

A mechanical device that protrudes from the gun when a round is in position ready to be fired, giving a visual and tactile indication that the gun is loaded.

Trigger Bar

On a semi-automatic pistol, or any other firearm in which the trigger is at some distance from the sear, this is an intermediate piece connecting the two parts.

Collapsible Stock

A stock on a long gun that can be shoved into itself to shorten it, either for storage or to make the gun fit shooters of different sizes.

Slide

The upper portion of a semi-automatic pistol that houses the barrel and contains the breechblock and portions of the firing mechanism. Ejecting the spent case as it moves to the rear and loading a fresh cartridge into the chamber as it moves forward again. As its name states, it slides along tracks in the top of the frame during the recoil process providing the linkage between the breechblock and barrel.

Pistol

Synonymous with "handgun." A gun that is generally held in one hand. It may be of the single-shot, multi-barrel, repeating or semi-automatic variety and includes revolvers.

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.

Cover

Anything a person can hide behind that will probably stopp a bullet.

Detonate

To explode with great violence. It is generally associated with high explosives e.g. TNT, dynamite, etc., and not with the relatively slow-burning smokeless gunpowders that are classed as propellants.

Cape Gun

A two-barreled, side-by-side, shoulder-fired gun having one smoothbore shotgun barrel and one rifled barrel.