Archives: Glossary

An opening in the wall of a barrel or chamber to allow the redirection of propellant gas. Usually associated with gas-operated actions or other mechanisms.

1. Any hole in the action of a firearm to allow the escape of gases from the breech. 2. A hole in the gas cylinder of a firearm to bleed off gas. 3. Ammunition: See Flash Hole. 4. See Barrel Vent.

1. A term used in the identification of most shotgun bores. (410 bore is an exception.) It is related to the number of bore diameter lead balls weighing one pound. 2. An instrument for measuring or testing a parameter.

A copper alloy with a nominal composition of 95 percent copper and 5 percent zinc. “Gilding Metal” is the trade name for the Copper Development Association, Inc. Alloy C21000. It is extensively, but not exclusively used in the manufacture of bullet jackets. See also “Commercial Bronze.”

The application of a mixture of fiberglass and resin between the action and/or barrel and stock.

A form of front sight usually used on target rifles generally cylindrical in shape and arranged to accept various inserts containing either rings or posts.

1. A unit of weight (avoirdupois), 7000 grains per pound. The grain unit is commonly used in American and English ammunition practice to measure the weight of components. 2. A term sometimes applied to a single particle of propellant powder. More properly called a kernel or granule.

1. In handguns, the handle. 2. In shoulder arms, that portion of the stock to the rear of the trigger.

A filler piece attached to the front of the grip of a firearm.

An auxiliary device on the grip of some handguns which is intended to prevent firing until depressed.