I have not picked it up yet, and I am not sure who makes it, its a Omega SD upper, so not sure whose they used. Ive heard RCM is very good, HKParts also makes combo units some hk and some american which I suspect is RCM.Who made the clone? Are you having issues with the current bolt group? Or looking for 922r conversion parts?
RCM is the best for the money. Anything marked H&K will be fine too but is going to cost near double the RCM parts. I've got RCM parts that have well over 15000 rounds of hard full auto use suppressed and unsuppressed and aside from a few extractor springs and some cleaning I have never had a problem with them