7.62x39 AR's have less meat on the bolt head than a standard bolt head; as I learned when my gun jammed on one of the busted lugs.
With a 7.62x39 AR, depending on what you're using it for, the 5- and 10 rd mags work fine, but if you want 20 or 30-rds, I'd recommend C-Products mags. However, the...