1 in 10 works for 150 Grains.
Yeah.... I had a boltgun made up on a Mauser action for this. I bought a barrel in .308 x 39 (yes, you heard me, it's a .308, not a .311) from Numrich Arms. .308 bore with the Russian case. It works. If you hadload, it works great
This works okay for factory AK ammo, even though it's squeezing the bullet a little. The massive M98 Mauser action is dealing with any excess pressure if I'm creating any - and I'm watching my primers... Handloads are its regular diet though, and since it's a true .308 bore, I have LOTS more options than if it were .311. I load "real 30 calibier" stuff anyway.
Anyway, this barrel has a 1 in 10 twist. I've been loading surplus .308 bullets, both in 147 grain boat tail and 150 grain flat base (both spitzer, fmj) and both of them are stabilizing just fine. Since a 1 in 10 twist works fine with 168 grains, that's a winter loading project for me, to see how this thing might shoot with actual match bullets. So far, though, 100 yard 3 shot groups are about one inch. Almost all groups are coming in the size of a quarter or less, so I'm satisifed. I haven't tweaked the loads much, but judging from the holes on the paper, they're for sure not keyholing or anything. Good luck.