I swapped the extractors only, I had German spares. It runs fine with the German extractor in the RCM bolt.
Prior to this I had issues similar to swiss seth where you could easily shake a case loose from the bolt face with all RCM parts. With the German extractor it's held much more securely to the bolt face.
Ditto, my D54N from joe started to have extraction issues after a couple hundred rounds (failure to eject, bolt head closing on the side of an empty case every 10-20 rounds. , bought a new spring and the german extractor ... and it worked fine. Its a RCM lug and RCM head ... not sure about the compontents. But that fixed the issue.