Letter M

The Definition of Mortar

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Mortar

An artillery piece used to fire shells over short ranges at very high trajectories.


19 Other Firearms Definitions You Need To Know


Trigger

The small lever on a cartridge firearm, which one pulls to cause the spring-loaded firing pin to impact the primer, causing the gun to discharge. Normally, the trigger simply connects to the sear. Pulling the trigger moves the sear out of its notch, releasing the spring-loaded hammer to strike the firing pin which in turn strikes the primer; or the coilspring-loaded firing pin directly. Other, often-Germanic systems have their own miniature lockwork which, when cocked, allows an exceedingly light trigger pull to discharge the firearm, a setting that would be perilous to carry in the field.

Handloading

The process of assembling cartridge case, bullet or shot, wads and primer to produce a complete cartridge with the use of hand tools in the interest of loading for firearms for which cartridges are not available, experimenting with loads to achieve better performance, or to save money. Not to be attempted without knowledgeable instruction and careful study of the process.

Primer Ring

Refers to a visible dark ring created by the primers in centerfire ammunition around the firing pin hole in the frame after much use.

Shotgun Shell

The cartridge for a shotgun. It is also called a "shell," and its body is usually made of plastic (metal shotgun shells are very rare, paper shotgun shells are extinct) with a metal head. Small shotshells are also made for rifles and handguns and are often used for vermin control.

Loaded

A firearm is loaded when a cartridge is in its firing chamber. However, for safety reasons all firearms are always treated as loaded at all times.

Casehardening

A heat-treating process that incorporates carbon into the surface molecular structure of the steel, providing a hard-wearing surface without making the entire receiver brittle. The parts to be casehardened are packed in a crucible with carbon-rich media such as bone meal and charcoal, heated to bright orange, about 1800F, then quenched in bubbling oil. Also called Carbonizing.

Checkering

A regular pattern of fine grooves cut into the surface of a stock to aid in gripping a gun. Originally done for utility only, checkering has become an art form in itself; craftsmen adorning the borders with ribbons, fleur-de-lys, floral carving, etc. The amount of coverage, the precise regularity, and the number of lines per inch indicate the quality of the work. Too-fine checkering, however, defeats the purpose of the work altogether.

Ambi

Short for the word Ambidextrous. Meaning that a feature of a firearms can be used by either hand, for example ambi-safety, ambi slide catch or ambi mag release.

Blank

A type of cartridge for a firearm that contains gunpowder but no bullet or shot. When fired, the blank makes a flash and an explosive sound (report). Blanks are often used for simulation (such as in historical reenactments, theatre and movie special effects), training, and for signaling (see starting pistol). Blank cartridges differ from dummy cartridges and snap caps, which are used for training or function testing firearms; these contain no primer or gunpowder, and are inert.

Mainspring

A strong spring which activates the striker or hammer of a firearm.

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.

Powder

The chemical propellant which is burned to produce the hot gases which send the projectile flying downrange.

Buttplate (Butt Plate)

A plate which covers the butt. Some steel buttplates have trap doors covering a recess for storage of cleaning equipment.

Grip

The portion of the stock (on a rifle) or frame (on a pistol) gripped by the trigger hand.

CQB

Abbreviation for Close Quarters Battle.

Low Kneeling

A shooting position in which one or both knees are touching the ground and the shooter is as low as possible.

Open Frame

Refers to a revolver frame that has no top-strap over the cylinder.

Overbore Capacity

Is that combination of caliber, barrel length, bullet weight, and case volume which does not allow the complete burning of the charge of ballistically correct powder within the volume of case and barrel.

Three Rules

The NRA teaches the Three Basic Rules of Safe Gun Handling. There are additional rules, but these are the three that if any two are followed, nobody will be hurt. However, obviously, all three should always be followed.

Rule One: ALWAYS keep the gun pointed in a safe direction.
Rule Two: ALWAYS keep your finger off the trigger until ready to shoot.
Rule Three: ALWAYS keep the gun unloaded until ready to use.
The NRA established these three rules in 1871. They were created to be easy to understand and remember, ensuring the highest possible level of firearm safety.
See also The Four Rules