A revolver with trigger mechanism for cocking a rotatable hammer. The revolver includes a frame, a barrel supported by the frame and defining a bore, at least one chamber aligned with the bore of barrel for holding a cartridge, a hammer pivotally mounted to the frame and moveable between a forward uncocked position and a rearward cocked position, and a trigger pivotally mounted to the frame. In one embodiment, the trigger includes a contoured camming surface configured and arranged to engage a protrusion extending outwards from the hammer for cocking the hammer in response to pulling the trigger. The protrusion may be a hammer dog pivotally coupled to the hammer in some embodiments. In another embodiment, the hammer may include a sear having a contoured camming surface for engaging the trigger.