A 1-12” twist in a 308 will stabilize flat base 200 grain jacketed bullets, at normal hunting velocities. I tried it in a Rem 700 Varmint Synthetic 308 Win. With 1-12” factory barrel and Speer 200 grain .308 bullets ( near max load of IMR 4350), with groups well under 1.5 moa.
Here’s a link from accuratereloading.com “medium bore” sub-forum. 308 Win shooters are reporting great accuracy with 220 grain jacketed bullets in 1-12” twist barrels ( with surprising velocity, 2350-2400 FPS).
http://forums.accuratereloading.com/eve/forums/a/tpc/f/3221043/m/4971014542Great rifle, and chambering. Get it and use it with confidence.