Originally Posted by armorer951

Most likely things to check: whether or not the extractor rod is out of alignment (run out), an issue with the yoke barrel being out of alignment, damage/wear to the offending ratchet as you suggested.
Excessive end shake can also play a role in how the hand interacts with the ratchet contact surface. You can't rule out impacted dirt inside the cylinder assy, or under/on the extractor itself. And, a missing extractor alignment pin or pins can also cause problems with the hand/extractor interface. Sorry, but the list goes on.

If the double action pull is smooth when cycled with the cylinder open and the thumbpiece held back, then the issue is most likely in the cylinder/yoke assy. somewhere.