The slide (or slideback) is the part of a semi-automatic pistol that moves during the operating cycle and generally houses the firing pin or striker, extractor, and serves as the bolt face. It is spring loaded so that once it has moved to its rearmost point in the firing cycle, spring tension brings it back to chamber a fresh cartridge.
Through the principles of recoil operation, the slide is forced back with each shot. Generally, this action serves three purposes - cocking the hammer or striker for the next shot, ejecting the spent casing, and loading another cartridge into the chamber. Once the magazine is empty, the slide will lock back, released only when the slide catch is depressed. Automatically cocking the hammer or striker is an important function of double action / single action pistols. However, some semi-auto pistols are double action only, and are designed to omit the first step.
