Abstract: The invention pertains to a gunlock safety device which is inserted into the barrel of a firearm. The gunlock includes an expander component consisting of several sections which are expanded inside the barrel to make frictional contact with the interior wall of the barrel. The several sections of the expander are expanded by a front and a rear wedge, as seen from the muzzle end of the firearm, which have conical ends. The expander has an inverted conical recess at each of its ends. The rear wedge has a rod extending into the breech of the firearm to thereby prevent any ammunition from being introduced into the barrel. The rear wedge has at its other end a shaft extending therefrom toward the front wedge. The shaft has a threaded end which will engage a threaded recess in the end of the front wedge.