Double Action

In a double-action revolver, pulling the trigger does two things: First, the hammer is pulled back to the cocked position while the cylinder is being rotated to the next round. Second, the hammer is released, striking the firing pin.

There are two subsequent action models: double action/single action where it is double action on the first shot, and then single action on the second and following shots, and double action-only where the firing mechanism cannot be cocked in a single-action stage.