The "ar47" design is a compromise. - Radical Firearms RF 7.62x39 M16 BCG, Melonite Bolt Carrier Group (BCG)

The "AR47" design is a compromise. Three things: bolt, hammer spring and firing pin.
To fit a 7.62x39 casing in a bolt designed for 5.56NATO, something has to give if you want the ability to use Mil-spec parts (Certain parts like the bolt can never be mil-spec, of course.).
The Comblock ammo has a harder primer, so needs slightly longer firing pin, as Mr "Bad misfiring BCG" discovered. They should include with the 7.62x39 AR BCG, but they don't, but firing pin is not expensive. Finally, I bought a lower spring kit, but have not needed it yet. The hammer spring will have problems eventually and is part of this kit.

If you don't want to compromise, you need to go to a proprietary solution (CMMG) or an AR10 chassis, perhaps. They tend to be significantly more expensive.

I've been shooting this platform since 2016, sometimes I'll do 500 round mag dumps. Frankly, I ride my horses hard and put them away wet. I still get reasonable reliability for hog hunting. (I can also afford to keep a second AR in the truck as insurance.)