[Ron-Solo]

I see a lot of stuff on 300 BLK but it looks like it is 7.62x35, making it a smaller round than 7.62x39, and I already have several rifles in that cartridge.

An AR10 would require a different receiver, rather than using one of my existing receivers.

Does 6.8 require anything different than a barrel, BCG, and new mags? All the ARs I've built we're 5.56.