A pistol is disclosed comprising a rod, including, in an end opposite to the trigger, a tip and a crosswise arm, wherein the crosswise arm is projected from the longitudinal body of the rod, towards the pistol central portion, and includes a front surface, able to interfere with the finger, and a flap, facing the crosswise arm and projecting downwards, in the middle region having an oblong hole; a rod guiding pin, with its crosswise axle parallel to the pistol length, crosses the oblong hole, to limit the movement upwards and downwards of the crosswise arm; and a rod ramp, in the shape of an oblong laminar body, fixed to a lower end on a crosswise axle and having a fold in the opposite and upper end, projecting away from the center of the pistol, defining a contact surface that mechanically acts against the tip.