Letter R

The Definition of Red Dot Sight

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Red Dot Sight

A type of reflector (reflex) sight for firearms that gives the uses a red light-emitting diode as a reticle to create an aimpoint.


19 Other Firearms Definitions You Need To Know


Ghost-Ring Sight

A type of aperture rear sight with a large opening and a thin rim that seems to fade out when the shooter looks through it. Sometimes installed on rifles and shotguns intended for home defense or police use.

Velocity

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

LFX

Abbreviation for Live Fire Exercise

Sight Alignment

The manner in which the sights are lined up properly in front of the shooter's eye, to form a straight path to the target.

Bang Stick

A specialized firearm used underwater that is fired when in direct contact with the target.

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.

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.

Federal Firearms License

A Federal Firearms License (FFL) is a license in the United States that enables an individual or a company to engage in a business pertaining to the manufacture of firearms and ammunition or the interstate and intrastate sale of firearms. Holding an FFL to engage in certain such activities has been a legal requirement within the United States since the enactment of the Gun Control Act of 1968.

Patch

A small piece of leather or cloth. A patch can refer to the wadding used in loading a muzzle loading firearms or the piece of cloth used to clean a firearm bore.

Magazine Loader

A mechanical device to make it easier to fill magazines using less hand strength and without hurting one's fingertips or thumbs.

Sawed-Off Shotgun

Common term for federally restricted "short-barreled shotgun (rifle)" as with a conventional shotgun with barrel less than 18" (rifle less than 16") or overall length less than 26.

Cylindro Conoidal Bullet

A hollow base bullet, shaped so that, when fired, the bullet will expand and seal the bore. It was invented by Captain John Norton of the British 34th Regiment in 1832, after he examined the blow pipe arrows used by the natives in India and found that their base was formed of elastic locus pith, which by its expansion against the inner surface of the blow pipe prevented the escape of air past it.

Heavy Trigger

A trigger that requires a lot of pressure to pull it past the break point. Rifles tend to have considerably lighter triggers than handguns, and even a heavy rifle trigger is often lighter than a light handgun trigger.

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.

Headspace

The distance, or clearance, between the base of a chambered cartridge and the breech face (or bolt face) of a firearm. This is a critical dimension, particularly in high powered rifles. If there is too little headspace, the bolt will not close. If there is too much headspace the cartridge will not be properly supported in the chamber and the cartridge will expand upon firing and may rupture, blasting high-pressure gas into the action and possibly into the body of the shooter. Headspace should be .003" - .006" in a centerfire rifle. It can be checked with a set of "Go and No-Go" gauges specific to the calibre in question. (See below.) With a standard cartridge, the headspace is registered by the shoulder, with a belted cartridge, the headspace is registered by the forward edge of the belt.

Length Of Pull

The distance from the front trigger of a shotgun to the centre of the butt.

Six O'Clock Hold

A sight picture of when the center of the target rests on top of the front sight when the sights are properly aligned. Also see center hold and cover hold.

Wildcat Cartridge

A wildcat cartridge, or wildcat, is a custom cartridge for which ammunition and/or firearms are not mass-produced. These cartridges are often created in order to optimize a certain performance characteristic (such as the power, size or efficiency) of an existing commercial cartridge. Developing and using wildcat cartridges does not generally serve a purpose in military or law enforcement; it is more a hobby for serious shooting, hunting, gunsmithing and handloading enthusiasts, particularly in the United States. There are potentially endless amounts of different kinds of wildcat cartridges: one source of gunsmithing equipment has a library of over 6,000 different wildcat cartridges for which they produce equipment such as chamber reamers.

Safety Lug

An extra flange behind the bolt handle, at the rear of a bolt action receiver (notably the Mauser Model 1898), which uses the bolt handle as an extra locking surface in the extremely unlikely event of forward bolt lug failure.