Letter O

The Definition of OTM

Arsenal Exchange - Firearms Classifieds - Industry Directory

19 Other Firearms Definitions You Need To Know


Suppressor

Incorrectoly sometimes referred to as a silencer, it is used to reduce the sound of a firearm's discharge. They do not actually silence most firearms but rather lower the intensity of the muzzle blast and change the sound characteristics (works similarly to an automotive muffler by disrupting and spreading out the sound waves). The possession, use, and transportation of silencers have been tightly controlled under federal law since 1934. Any device which reduces the sound of discharge by more than 2 dB is considered by the BATF to be a suppressor.

GAP

Abbreviation for Glock Auto Pistol

Lever Action

A type of firearm action which uses a lever located around the trigger guard area, (often including the trigger guard itself) to load fresh cartridges into the chamber of the barrel when the lever is worked.

Trigger Safety

An external, passive safety which can be found on the face of some trigger designs (most notably found on Glock firearms). It is intended to prevent the trigger from being pulled by objects which find their way into the trigger guard area.

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.

Antique Firearm

Defined according to Section 921 (a) (16), Title 18, U.S.C. as:

A. any firearm (including any firearm with matchlock, flintlock, percussion cap, or similar type of ignition system) manufactured in or before 1898; and
B. any replica of any firearm described in subparagraph (A) if such replica (i) is not designed or redesigned for using rimfire or conventional centerfire fixed ammunition, or (ii) uses rimfire or conventional centerfire fixed ammunition which is no longer manufactured in the United States and which is not readily available in the ordinary channels of commercial trade.

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.

Bullpup

A firearm configuration where the magazine and action are behind the trigger.

Field Grade

A plain, functional, unembellished firearm used to hunt in rough terrain where one might prefer not to put a more expensive, deluxe grade gun at risk of damage.

Slide Release

A slang term for slide catch.

Velocity

The speed at which a projectile travels. Velocity is usually measured in feet per second or metres per second.

Funeral Grade

A colloquial term to describe a break-open gun, of any quality but often of the very highest, bearing the least possible decoration; having an all-blued receiver with either no engraving at all or only a simple borderline.

Passive Safety

Any safety, internal or external, which functions apart from the shooter's conscious control. Grip safeties are one example of a passive external safety.

Delayed Blowback

A self-loading firearm whose breechblock and barrel are not positively locked together, but which incorporates a mechanism which initially restricts the breechblock from moving when fired, delaying its opening.

Riding the Slide

Racking the slide incorrectly by allowing your hand to rest upon the slide as it moves forward during the loading procedure. Riding the slide is a common cause of misfeeds and other malfunctions.

Jump

The amount of change in the bore axis, measured both vertically and horizontally, while the projectile moves from the chamber to the muzzle when it is fired.

Action

The working mechanism of a firearm involved with presenting the cartridge for firing, and in removing the spent casing and introducing a fresh cartridge. For example some of the most common types of Actions are single, double, bolt, lever and pump.

Base Wad

The paper filler at the rear of the powder charge of the shotgun shell.

Cut-Away

A firearm that has had numerous careful machining cuts taken in its exterior with a view to exposing and demonstrating the functioning of critical parts of its mechanism