The Double action revolver use a long trigger pull to cock the hammer, thus negating the need to manually cock the hammer between shots. The disadvantage of this is the long, heavy pull that cocks the hammer makes the double action revolver much harder to shoot accurately than a single action revolver (although cocking the hammer of a double action reduces the length and weight of the trigger pull). There is a rare class of revolvers, the automatic revolver, that attempts to overcome this restriction, giving the high speed of a double action with the trigger effort of a single action.