I have a 308 T3 Tactical with a 20" barrel. The barrel is a 1-11" twist, when I look at Hornady 178 AMAX they say 1-10". At this twist rate where am I going to run into problems with stability? I really want to run this rifle out to 600yds. Any suggestions? Also, with Varget and RE15 can I run benchrest primers or should I run Magnum primers?