I've always kind of liked the idea of a bolt action in 9mm or .45 for trying to get a super-quiet centerfire rifle. If you pulled the RDB BCG from a CMMG and replaced it with a standard bolt carrier with a 5.45x39 bolt, would it more or less create a straight-pull 9mm bolt action? My understanding is that the RDB uses a standard AR15 barrel extension but that the bolt is what has the angled cuts on it? Seems like a standard bolt with non-angled lugs would remain locked after each shot, thereby eliminating all action noise and port pop. 5.45x39 seems to have about the same casehead diameter as 9mm, so that aspect seems compatible.

Thoughts?

I asked if the extension was proprietary and CMMG said it was.
You may have headspace issues even if you can get it to lock.

You can get bolts/barrels from Macon Armory or RMW and use any upper/carrier.

Yes, it will be a single shot...discussed several times.  
Also had a custom barrel made with standard extension and it works fine .
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