7.62 X 39 Build Question

AR/M4 Beyond 5.56/.223
1

I am about to do a 7.62 X 39 build, what things do I need to look out for?

2

I am far from being an expert on the matter, but I slapped a Colt flat-top upper on a RRA lower, and using C-Prods magazines, I was GTG.

3

The only difference is the barrel and bolt.
Harrison at ARperformance makes 7.62x39 “superbolts”…
I am unsure what the optimal barrel specs are for that caliber.

4

I am gonna do an ER Shaw barrel with that ARperformance bolt inside a BCM Carrier.