I must offer the caveat that I may indeed be very wrong about this. I just purchased a 4596 from GB for 550.00 because I know only 382 of these were made apparently. If I understand the description from the SW book it is a 4506-1 mated to a 4516-1 slide. Assuming that will be the case I would imagine any 645, 4506, 4566, 4586, 4546, 4576 magazine would work. Probably others but I am tired and reeling off what I think would work.