Decocker

A decocker is a mechanism found on some firearms, most commonly semi-automatic pistols, that allows the hammer to be safely lowered from a cocked position to a resting or uncocked state without firing the weapon. This is achieved by manually manipulating the decocker lever or button, which in turn controls the movement of the hammer. When the decocker is engaged, it typically causes the hammer to fall, but prevents it from striking the firing pin with enough force to discharge a round.

The primary purpose of a decocker is to enhance safety by allowing a pistol to be carried with a round in the chamber and the hammer down, but still ready to be fired quickly by simply pulling the trigger or, in some designs, by cocking the hammer. This contrasts with carrying a pistol with the hammer cocked and the safety engaged, or carrying it "cocked and locked" which requires the safety to be disengaged before firing. Decocker mechanisms vary between firearm manufacturers and models, with some decockers also acting as safeties, while others are separate functions. It is important for users to understand the specific operation of their firearm's decocker.