I have a Glock 19 with Meprolight night sights that came on it. The point of impact is about 6 inches high at 15 yards over the point of aim. I have not done anything to the pistol that should affect the point of impact. Before I put a new set of sights on it,is there anything I might be overlooking that would cause this? I am thinking about going with the Truglo TFO sights if I replace them.