Archives: Glossary

A generic term applied to many variations of small one-or two-shot pistols, using both percussion caps and cartridges. The original designer, Henry Deringer, spelled his name Deringer, not Derringer.

Most foreign and some American commercial cartridges are identified by their nominal bullet diameter and cartridge case length, both of which are given in millimeters-e.g., 8×57, 7×57, 6.5x54mm.

Indentation used as a stop for a spring-load lock.

An extremely rapid exothermic decomposition reaction which proceeds at a rate greater than the speed of sound within the reacting material (unlike DEFLAGRATION). The normal mode of initiation is shock (such as a blasting cap or high level mechanical shock), or from initial combustion which, due to peculiarities of confinement or other circumstances accelerates to such a degree that a shock wave is formed. Behind the shock wave is a reaction zone where material is converted to gaseous products at high temperature and pressure. The flow of the reaction is in the same direction as the propagation.

An acronym for DEactivated WAr Trophy.

To cause a firearm to fire.

A device intended to disengage the sear from the trigger. 1.) In a manually operated firearm, it is intended to prevent firing without pulling the trigger. 2.) In a semiautomatic firearm, it is intended to prevent full automatic firing. 3. A device that prevents out-of-battery firing.

Bullet that breaks into small pieces in flight or upon impact with the target.

A projectile that breaks up after leaving the muzzle and before it hits the target.

An electronic pulse forming device used in measuring projectile velocities.