PROPELLANT

In a firearm, the chemical composition which, when ignited by a primer, generates gas. The gas propels the projectile. Also called powder, gunpowder, smokeless powder, blackpowder.

PUMP ACTION

An action in which a moveable fore-end is manually actuated in a motion generally parallel to the barrel. This motion is transmitted to a breech bolt assembly which performs all the functions for loading and extracting cartridges. This type of action is prevalent in shotguns and is found to a lesser extent in rifles.