I had a problem once that I think was about the same.
I bought a LNIB Model 34 22LR revolver on Gun Broker.
Brought it to indoor range and tried every brand of ammo I had and range had to no avail, nothing would go into chambers.
i called Smith customer service and was told I had to pay for everything as it was too old.
I thought whatever, it is a paper weight.
It came back two weeks later and was perfect, I never got a call, never saw a bill.
That is the kind of service I am accustomed to from S&W.
I am quite sure someone forgot some final honing step , but it also was never test fired, stuff happens !!!
I would think your gun is about the same, just not as bad as mine was.
Now, remember, they have only two guys repairing guns on a regular basis, one who does most revolvers and one who works on autos.
Now, they have may have other people for newer stuff too, I only have older stuff.
So, they obviously do not have a lot of issues or it would take more then two !!
Chris