EXPLOSION

The sudden release of energy of sufficient magnitude to create a pressure wave. The energy to produce an explosion may come from a variety of sources; including nuclear, pressure or chemical reaction. 1. Examples of pressure related explosions include a rapid change in state (liquid to gas, for example) or by the over pressurization of a container (i.e., the failure of a gas cylinder). 2. A chemical explosion is the event in which a quantity of matter is instantaneously converted to gaseous product, with the generation of high temperature and pressure.

EXPRESS SIGHT

A rear sight that incorporates a shallow “V” sight notch. They are used for fast target acquisition and are typically found on rifles intended for use on dangerous game.

EXTERIOR BALLISTICS

The branch of Applied Mechanics related to the motion of a projectile from the muzzle of a firearm to the target.

EXTRACTION

The act of withdrawing a cartridge or fired case from the chamber of a firearm.

EXTRACTOR

Device for withdrawing the cartridge or fired case from the chamber.

EXTRACTOR CUT

Usually a recess in the barrel of a firearm to accommodate an extractor.

EXTRACTOR GROOVE

A groove turned in the side wall of a cartridge case just forward of the rim for the purpose of extraction.

EXTREME SPREAD

The distance between the centers of the two shots which are the farthest apart of a group of shots on a target.