I've replaced a couple of Smith & Wesson bolts just by dropping in the new parts. The Brownells people seem to be able to keep the Smith & Wesson frames and parts straight. I haven't replaced a hand in quite a few years, but usually ordered standard and just dropped them in, checked them, and had good success. The one time I needed a slightly longer hand to accommodate a friend's worn star, Brownells had what I needed. I ended up having to shorten it a skosh, but that beat the socks off having to try to lengthen it.