Your .308 WIN is a very good dog gun. I use a Rem 700VS in 308, 26" barrell 1:10 twist (cryo treated and fire lapped barrel). I have good accuracy with Varget using 168G HPBT match bullets, but not much with any other bullet weight. Give up on 3400FPS; go to the Speer 125 TNTHP bullet for good...