4596s were Lew Horton guns; a one-time production run of less than 400 units. If my recollection is correct, they were cobbled together from a 4506 receiver and a 4516 slide. Eight plus one rounds, 3-inch barrel, square trigger guard. It is a really great, smooth-shooting pistol with no bad habits. I carried mine as a duty weapon for twelve years. My only complaint is that it is heavy.