7.62x39 upper same as 5.56?

[Former Cav]

http://palmettostatearmory.com/
I bought a lower from them and it works great.
I'm thinking of buying a 6.8 upper... but your AK size ammo idea has merit as well

[C5M1]

300 blackout would be my only option in 30 cal for the AR platform. Identical to x39 except all that needs changing is the barrel.


regards, dennis