UPDATE: During my last post in this thread almost a year ago to the day I mentioned I like the 7.62x39 and have a Bushmaster AR in that caliber. I also said I'd get an upper (or complete rifle) in 300 AAC if I got the funds and could find one. Well, I got that upper in 300 Blackout during the holidays and love it! My new fun gun is made by Diamondback. Bullet and handling characteristics are similar to the AK round, just a bit more accurate (at least in my gun) beyond 50 yards plus it has the advantage of using the same 5.56 mags as my other ARs. You can also get heavier weight, sub sonic bullets in 200 grain plus sizes that you don't find in a 7.62X39. On the down side, the ammo for the AAC is twice (minimum) as expensive as the AK stuff and MUCH harder to find, especially the sub sonic rounds.
All in all, the 300 AAC seems to have found that perfect balance between the AK and AR rounds, offering the best of both worlds with the Blackout being more flexible and reliable in an AR style rifle. OTOH, the 7.62x39 is hands down the most affordable and available of the two rounds and with the correct magazines, is very reliable in an AR.
For now, my choice would the 7.62x39 if the world as we know it ends and the zombies take control (it's already happening in Washington) due to availability and price. For hunting and other uses where you need fewer rounds on target and better performance, I'd use the 300 Blackout. Both calibers have strong pros and cons and only time will tell who the ultimate last man standing will be.
"... Americans... we want a safe home, to keep the money we make and shoot bad guys." -- Denny Crane
Last edited by rachilders; 02-28-2014 at 02:49 PM.