Letter F

The Definition of Four Rules

Arsenal Exchange - Firearms Classifieds - Industry Directory

Four Rules

The four rules of firearms safety,were originally introduced in the early 1900's by various shooting education sources (with varying phrasing, but same implications), they apply every single time a firearm is handled in any way or for any reason. The NRA teaches the Three Rules of Safe Gun Handling.

Rule One: All guns are always loaded. (Treat all guns as if they are loaded, no matter what!)
Rule Two: Never point your firearm at anything you are not willing to destroy.
Rule Three: Never put your finger on the trigger unless your sights are on target (and you have made the decision to fire).
Rule Four: Be sure of your target and what is behind it.

19 Other Firearms Definitions You Need To Know


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.

Trigger Control

Not putting your finger on the trigger until your sights are on target, then pulling the trigger smoothly, and following through by realigning the sights before allowing your finger to come off the trigger.

Right To Bear Arms

The unalienable right of all of the people, stated in the Second Article of The Bill of Rights, to possess and use personally owned firearms for sport, recreation, personal protection, and the defense of the nation.


The original small single-shot or multi-barreled pocket pistol designed and manufactured by Henry Deringer of Philadelphia. Derringers (spelled with two Rs) are called that because of the original desinger and anmufactuturer of that type of gun, Henry Deringer. To get around copyright infringment other designers and manufacturers spell the name with two Rs. However guns designed and built by Deringer are spelled with only one R


An early form of complete, self-contained cartridge. It included bullet, powder and ignition primer, all in one package. The primer was located towards the base of the cartridge, but completely internally. The pin, shaped like a little finishing nail, pointed on the inside end and resting on the internal primer, projected radially about a quarter-inch to the outside of the base of the cartridge. When loaded, a pinfire gun showed the tips of the pins exposed through small slots in the tops of the breech faces of the barrels. To fire, hammers fell on the pins, driving them (through the wall of the cartridge) into the internal primer.

Adjustable Stock

The stock is the wooden, polymer, or metal handle of a long gun that extends from the trigger back to where the gun is braced against the shoulder. An adjustable stock is one that can be easily lengthened or shortened to fit shooters of different sizes.


A gun with more than one barrel, the most common being the double-barreled shotgun.


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.

Hang Fire

An unexpected delay between the triggering of a firearm and the ignition of the propellant. This failure was common in firearm actions that relied on open primer pans, due to the poor or inconsistent quality of the powder. Modern weapons are susceptible, particularly if the ammunition has been stored in an environment outside of the design specifications. Reloaded ammunition may also be the cause if not reloaded properly


An early form of muzzle-loading revolver wherein, instead of the current practice of having one barrel mated to a multi-chambered rotating cylinder, multiple joined barrels revolve together around a central axis.


Sometimes spelled Bi-Pod. A support device that is similar to a tripod or monopod, but with two legs. On firearms, bipods are commonly used on rifles to provide a forward rest and reduce motion. The bipod permits the operator to rest the weapon on the ground, a low wall, or other object, reducing operator fatigue and permitting increased accuracy.

Trigger Jerk

Yanking the trigger back abruptly, thus pulling the muzzle of the gun downward at the moment the shot fires.

Short Recoil

A semi-automatic pistol in which the barrel and breechblock are locked together for only a short distance of rearward recoil travel, at which point the two are uncoupled, the barrel is stopped and the breechblock continues rearward, extracting the spent casing from the chamber. Upon returning forward, the breechblock chambers a fresh round and forces the barrel back into its forward position. Most modern recoil operated semi-automatic pistols use short recoil.


A matrix of dots, posts or lines, visible inside a rifle's telescopic sight, normally adjustable via exterior knobs for windage and elevation. After careful adjustment at a known range, the shooter aims the rifle by superimposing this matrix onto the target. With good estimation or range, cooperation from the wind, a clear eye and a steady hand, he may have a reasonable expectation of hitting his target.

Point of Aim

The point at which you are aiming the firearm at.


The beginning of the bore of a rifled firearm. The transition between the chamber and the rifling. The area most vulnerable to erosion from high velocity cartridges.


Abbreviation for Federal Firearms [Dealer's] License.

Recoil Lug

A stout flange, invariably incorporated into the underside of the front receiver ring of a bolt action, and also frequently incorporated into the underside of the barrel of a heavily-recoiling rifle, which when properly bedded, transfers recoil to the stock.

Hot Range

A condition (status) of a shooting range that shooters may commence to fire.