I was talking to one of the Customers at
Sportsman's Warehouse (aka He-Man Warrior Store) last night and he was telling me the same thing. He did not own an AR-15 in this calibre, but he had heard that there were feeding issues with the 7.62 X 39 ammo.
Your reasoning about the comparison to the 6.8 mm Remington SPC (or 6.8×43mm) is fairly sound, though the 6.8 has the edge over the 7.62 Russian. The two fire similar bullet weights, and you are so correct that the 7.62 X 39 is just so much cheaper to shoot. Great minds think alike.
I have a nice back-stock of Wolf Ammo, and that would be the ammo that I would be shooting primarily....so good to know about the Mag Springs, thank you very much for that insight.
Right now it looks like I can get one from DPMS or Armalite....I've heard good things about Armalite, and mixed impressions about DPMS.
Anybody have opinions about these two manufacturers?