Abstract: A double-action revolver has a hammer assembly which includes a mechanism for positively defining the displacement and the engagement positions of the sear to insure accurate and smooth coaction of the sear with the trigger mechanism.The trigger assembly includes a cylinder-actuating hand, trigger lever, and transfer slide which is raised by the trigger to a position where it is struck by the hammer to percuss the firing pin. Percussing of the firing pin can only be accomplished by coaction of the trigger and hammer, thereby eliminating the requirement for a hammer block or other safety device.The handle of the revolver includes a wedge-shaped section adapted to fit snugly in the web of the palm between the thumb and first finger, while the butt of the handle fits in the hypothenar eminence area of the palm, so that the handle will be stably held at both its upper and lower ends during the firing cycle of the revolver, to prevent bucking or twisting of the revolver when it is discharged.