Abstract: A double action revolver has a frame on which is mounted a cylinder, a trigger and a hammer. A hammer or main spring is interposed between the trigger and hammer such that pulling the trigger causes the spring to compress and bias the hammer toward its fired position. The position of the hammer remains essentially unchanged during initial trigger pull by virtue of a toggle spring device interposed between the frame and the hammer. When the hammer spring is sufficiently compressed, a surface on the trigger contacts and engenders a deflection or buckling of the toggle spring device. Buckling of the toggle spring device permits the hammer spring to drive the hammer to the fired position in which a cartridge is fired.A spring loaded cylinder stop, having a projection adapted to be received in a locking recess on the cylinder, is adapted to be displaced forwardly, against the bias of its spring load during initial trigger return from the pulled position to its normal or released position.