It looks to me as if, performance wise, the 300 AAC/Blackout falls somewhere between the 7.62x39 and the 30-30. Is that correct?

I'm asking because a friend asked me to recommend between the RAR-RR in 300 AAC/Blackout and the RAR-P in 308. I told him that the 308 would be easier to find and cheaper to shoot, since he doesn't reload, but he hasn't bought either yet.