I don't know about in a smoothbore that short, but I do know that I fired a derringer in 45/410 with the 2 1/2" shells at 25' and it filled a 2'x3' target with an almost bare spot in the center 9" area. For self defense it would blind and cause arm and leg damage at that distance, but little damage to vital areas. Show us some field trials when you get out to a range.