I picked up a second hand 617-4 with an 8 3/8" barrel that seems not to be indexed properly. When viewed from the rear sight, the front sight is turned slightly to the right. The ribbing along the top of the barrel also does not line up perfectly to that on the frame - again it's canted to the right when viewed from the rear.

If I were to send this back to S&W, would they be able to index the barrel properly and trim the barrel back a smidge to maintain the gap? Or does the barrel tighten the other way - and I'd have to deal with a greater gap?

The barrel threads are right-handed, which means that setting the front sight vertical would tighten the barrel-to-frame assembly and will slightly decrease the barrel-to-cylinder gap.

..which is a good thing!

Thanks!