Letter S

The Definition of SP

Arsenal Exchange - Firearms Classifieds - Industry Directory

19 Other Firearms Definitions You Need To Know


Choke Tubes

Short, interchangeable cylinders, of subtly different internal tapers, that screw into a threaded recess at the muzzle of a shotgun. By inserting different choke tubes, one can alter the shot pattern thrown by the gun.

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.

Load

A charge of powder, a projectile or a cartridge. Also, to prepare a gun for firing by inserting ammunition into it.

Integral Lock

A built in lock that may prevent the firearm from being fired.

Receiver

The housing for a firearm's breech (portion of the barrel with chamber into which a cartridge or projectile is loaded) and firing mechanism. In semi-automatic handguns and revolvers, this part is typically called the frame.

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.

HMR

Abbreviation for Hornady Magnum Rimfire.

Ejection Rod

The sliding metal dowel located at the muzzle end of a revolver cylinder. After firing, the shooter opens the cylinder and depresses the front end of the ejection rod, which forces the empty cases out of the cylinder.

Fouling

The accumulation of unwanted material on solid surfaces. The fouling material can consist of either powder, lubrication residue, or bullet material such as lead or copper.

Long Recoil

A semi-automatic pistol in which the barrel and breechblock are locked together for the full distance of rearward recoil travel, after which the barrel returns forward, while the breechblock is held back. After the barrel has fully returned, the breechblock is released to fly forward, chambering a fresh round in the process.

Safe

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

Co-Witness Sighting

Co-Witness Sighting is the use of any iron sight mounted onto a rifle that is fitted with an optical sight as a primary sighting system. They come in two basic configurations, fixed or flip-up. The idea is that if you align your red dot and your iron sights you have a backup aiming system on the gun.

Crisp Trigger

A trigger that breaks (to release the hammer) easy.

Tap, Rack, Bang

The slang term for the procedure to clear a misfeed. To clear a misfeed, tap the base of the magazine firmly to be sure it is properly seated, rack the slide to eject an empty case or feed a new round, and assess to be sure your target still needs shooting. If it does, pull the trigger to create the bang.

Primer

A small metal cup that contains a tiny explosive charge that is sensitive to impact. A primer is placed in the base of a shell casing to ignite the powder of the completed cartridge. It is detonated by the striking of a firing pin in the firearm.

Fouling Shot

A fouling shot is a shot fired through a clean bore, intended to leave some residue of firing and prepare the bore for more consistent performance in subsequent shots. The first shot through a clean bore will behave differently from subsequent shots through a bore with traces of powder residue, resulting in a different point of impact.

POA

Abbreviation for Point of Aim

Gas Vent

A passage built into a firearm to allow the safe conduct of unexpected gas, as from a pierced primer, to minimize damage both to the gun and to the shooter.

Propellant

The substance which imparts movement to the projectile in a firearm. In a firearm, usually powder. In an airgun the propellant is air or Co2