Another advantage of .308 in a bolt gun is the odd ball bullet diameter of the 7.62x39 bullet, .313". Bullet selection is rather limited to the handloader compared to .308" bullets. I have loaded .308 bullets in 7.62x39 brass. In an SKS, not the most accurate rifle on the planet, it's hard to tell any difference. I got about 3.5" groups at 100 yards. With Wolf or Tula 154 SP I get 2.5" 100 yard groups, but the handloads were about as accurate as 123 FMJ. In a bolt gun, though, you could do much better with the bullet matching bore diameter. As a handloader, for an accurate rifle, I prefer .308 which is every bit as accurate a round as 7.62x39 in at its best. My hunting load in .308 from my Remington M7 Stainless gets 3/4 MOA from the bench. I'm loading a 150 Nosler BT. It has killed many hogs and deer and I made a 370 yard lasered shot on a coyote with it, once.