Abstract: A gun sight intended for detachable mounting on the rear of a barrel of a shotgun to provide an accurate aiming of the gun barrel with use of the front sight thereof to provide increased accuracy of the gun when used with a single shot slug rather than a conventional shotgun shell, the sight including a base adapted to frictionally mount the sight of the shotgun barrel, and a sight mounted on the base. A modified embodiment of the invention further includes a sight adjustably mounted on the base to provide adjustment for both windage and elevation, and an elevation bar movable relative to the sight and the base for adjusting the elevation of the sight.