What is a double-action pistol?

A double-action pistol can be cocked and fired with one trigger pull. Pulling the trigger of a double-action pistol moves the hammer backwards, compressing the spring and cocking the pistol automatically. Releasing the trigger fires the gun.

Many double-action pistols can be used in both double- and single-action mode. They can be cocked manually by pulling the hammer backward and fired by pulling the trigger to release the hammer. The trigger moves more easily and requires less pressure when the gun is already cocked. Such pistols re-cock automatically for successive shots. However, some double-action pistols are double-action only, and they can only be cocked by pulling the trigger.