357 SIG is about the best round in my opinion for an auto. Yes, I do own some 1911's and I do own some 9mm's but that little SIG just plain makes me smile when I think about it, "Supposed" tobe the close to equal with the 357 Mag, it comes darned close. You'd be better off to stick with the 124-125 bullets, small case for anything bigger, start losing to much velocity.