Welcome and sorry for your troubles.

The hammer and trigger on these are case-hardened, so the former appearing "painted" is probably normal.

With older standard S & W revolvers the usual cause of this problem is a loose extractor rod tying up the action, but the 500 and 460 don't use the rod as a locking point. If the thumb piece (cylinder release) is fully forward and the gun doesn't unlock, I agree with sending it back to the factory to be sorted out.

__________________
Alan
SWCA LM 2023, SWHF 220