I suspect that S&W will repair or replace your 642 very quickly ...
Despite what some folks have said about me, I'm not a S&W apologist ... or a paid promoter, for that matter.
I DO really, really like my 642-1 ...
During the 70's, 80's and into the 90's ... if I wanted to pick up a revolver and have it reliably function and shoot right out of the box ... I picked a Ruger. Day in, day out ... single action or double action ... I picked a Ruger.
Sure, I had to return a Redhawk once for a defective hammer ... but I've had to have more S&W revolvers repaired for problems than Rugers.
Rugers aren't "pretty" when it comes to finish, and they'll never have the really nice triggers of the S&W's & Colts ... but they're generally robust and reliable.
My 642-1 was the first S&W I was able to take out of the box and shoot it until I got tired of shooting ... and then do it again ... and again ... etc., etc.
The head armorer at work is a S&W revolver armorer. We've seen quite a number of late model S&W revolvers come through our range, and he's commented on how they're pretty much fine and functional compared to previous years. I hope this is a trend, and brought about by the new American ownership.
I will never again buy anything that is, was or ever will be made by anyone using the Charter Arms name and design ...
I won't buy a Taurus ... although I'll review that opinion, again, in another 5-10 years.