A while ago I purchased a nickel 29-2 that, as it turns out, had a timing issue, and the cylinder was binding. It turned out that the barrel to cylinder gap was zero and the cylinder was rubbing on the barrel. I thought that cutting the breach, therefore opening the gap, would solve the binding problem, which it did. However, over time, the drag on the cylinder had caused excessive wear on the ratchet on the extractor star and that seemed to be the cause of the bad timing. I was able to procure a new cylinder complete. That solved the timing issue and the gun shoots great, but it turns out the new cylinder was 1.745” and the old cylinder is 1.749, resulting in excessive B/C gap, which had I set for the long cylinder. I tried swapping the star and other parts from the new cylinder onto the old longer cylinder, but the star does not fit.
Now my question is: will I harm the gun by shooting it with a B/C gap of .007”-.008”? I don’t plan on shooting the gun very much, but when I use .44 magnum loads there is a pretty substantial fire coming out of the gap. .44 special loads obviously don’t produce as much blast. Is there a fix, outside setting the barrel back? I’m pretty sure the original long cylinder would solve the gap problem if I could get a star to fit. Thank you.

Why don't you just send it to S&W and have them re-set the barrel back to lessen the gap?

I'd just shoot it. In a perfect world I'd like less than your .007-.008" gap but it wouldn't bother me enough to have the barrel set back.

Would a slightly thicker hand fix the timing issue with the original cylinder and "star"? Even "std" hands vary a few thousandths, enough to allow "adjustment" without going to an oversize hand.

You will be fine shooting that gun as it is. There are a lot of nice shooting revolvers with 6-.008" gap and if you shoot lead bullets mostly you will find it very helpful since a very close fitting cylinder will touch from time to time from lead build up. I would certainly not send it out and have the barrel set back for something like this. Your gap is not considered excessive except for perhaps a new gun and really is more common than not.

Now if you reload for this gun you can experiment and find a load that will shoot cleaner with less flash and splatter and not even know you have an extra couple thousands up there.

I did consider a new hand. If that had worked it would have been less expensive than a complete cylinder. I might just go back to the long cylinder with a new hand. If the timing issue is resolved the B/C gap would be fixed as well. This has turned into a project gun and a great learning experience. Another 20 bucks and 45 minutes on this thing won't make much difference to me. It is very accurate as it is, but I'm inclined to keep on tweaking. Thanks to all for the responses.