Letter T

The Definition of Trigger Scale

Arsenal Exchange - Firearms Classifieds - Industry Directory

19 Other Firearms Definitions You Need To Know


NFA

National Firearms Act of 1934. Enacted on June 26, 1934, currently codified as amended as I.R.C. ch. 53, is an Act of Congress in the United States that, in general, imposes a statutory excise tax on the manufacture and transfer of certain firearms and mandates the registration of those firearms. The Act was passed shortly after the repeal of Prohibition. The NFA is also referred to as Title II of the Federal firearms laws.
The NFA includes:

  • Requires the registration of all fully automatic firearms.
  • Requires the registration of all "sawed off" rifles and shotguns.
  • Requires the registration of firearm silencers.
  • Imposes a $200 transfer tax on the above items.

High Brass

By convention, powerfully loaded shotgun cartridges for hunting are generally manufactured with relatively longer brass end-caps than lower powered cartridges intended for target shooting. While different-sized brass bases are of virtually no consequence to the strength of the shell in relation to the steel breech of the gun itself, they do help the shooter identify the relative power of cartridges at a glance.

Extractors

A part in a firearm that serves to remove brass cases of fired ammunition after the ammunition has been fired. When the gun's action cycles, the extractor lifts or removes the spent brass casing from the firing chamber.

Point of Impact

The point where the projectile from a firearm hits.

Iron Sights

The mechanical sighting system which usually comes with the firearm made of metal with no optics.

Straddle Floorplate

A hinged plate covering the bottom of a rifle magazine and extending rearward on either side of the triggerguard. This design allows it to be more securely fastened for one more imperceptible step towards total reliability.

Reflector Sight

A generally non-magnifying optical device that has an optically collimated reticle, allowing the user to look through a partially reflecting glass element and see a parallax free cross hair or other projected aiming point superimposed on the field of view. Invented in 1900 but not generally used on firearms until reliably illuminated versions were invented in the late 1970s (usually referred to by the abbreviation "reflex sight").

Hammer

The part of the gun that strikes either the firing pin or the round directly when the trigger is pulled then detonates the primer of the load and discharges the gun. Hammers may be external or internal. On a striker fired gun (a gun without a physical hammer) the firing pin is considered the hammer since it releases directly when the trigger is pulled.

Heel

The top of the butt-end of a gun stock.

Detonate

To explode with great violence. It is generally associated with high explosives e.g. TNT, dynamite, etc., and not with the relatively slow-burning smokeless gunpowders that are classed as propellants.

Brady Law

Brady Handgun Violence Prevention Act of 1993. The Brady Handgun Violence Prevention Act of 1993 mandates background checks of gun buyers in order to prevent sales to people prohibited under the Gun Control Act of 1968 legislation. Requires checks to be performed through the FBI's National Instant Criminal Background Check System (NICS). Records of who has been checked are not preserved because federal law prohibits the creation of a national registry of gun ownership. Sales by unlicensed private sellers who are not engaged in gun dealing as a business are not subject to the checks under federal law, though they are required by some states.

Doll's Head

A rib extension on a break-open gun, ending in a circular or semi-circular shape in plan (resembling the head of a doll), mating into a similarly-shaped recess in the top of the receiver, designed to resist the tendency of the barrels to pull away from the standing breech when firing. Because an action's centerpoint of flexing when firing is at the base of the standing breech, not at the hingepin, a passive doll's head extension makes an effective extra fastener, even without additional mechanical locks operated by the opening lever.

Single Action

An action type that when the trigger is pulled, the only thing the trigger does is drop the hammer (or striker). This applies to both revolvers, semi-automatic and automatic guns. On a single action revolver, the gun must be manually cocked before it can be fired. With semi-automatic and automatic guns that are single action, the only thing the trigger does is drop the hammer, striker or firing pin onto the cartridge. Then the firearm is cocked again when from the recoil of the fired round. A firearm that the gun is cocked and the hammer drops when the trigger is pulled is a double action gun.

Double-Barreled Shotgun

A shotgun with two barrels, usually of the same gauge or bore. The two types of double-barreled shotguns are over/under (abbreviated as O/U or OU), in which the two barrels are stacked on top of each other, and side-by-side (abbreviated as SxS), in which the two barrels sit beside each other. See photo at right for example of side-by-side double-barreled shotgun. For double-barreled guns that use one shotgun barrel and one rifle barrel, see combination gun.

Rimless

A cartridge in which the base diameter is the same as the body diameter. The casing will normally have an extraction groove machined around it near the base, creating a "rim" at the base that is the same diameter as the body diameter.

Extended Top Tang

A display of gunmaking skill with a possible benefit of strengthening the wrist of a heavily-recoiling rifle, whereby the top tang of the action is made extra long, shaped and inletted into the top of the buttstock, extending along the top of the wrist and up over the comb. Popularized by Holland & Holland and adopted by several of the finest contemporary riflemakers in the USA.

Buttplate (Butt Plate)

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

Cylinder Drum

On a revolver, a spring activated device housed in the bottom of the frame beneath the cylinder that engages alignment notches in the cylinder. It stops the cylinder's rotation and holds it in place each time a chamber in the cylinder is in alignment with the barrel.

Clicks

A unit of adjustment for a sight.