I have a 26" 1 in 12" 308, its the standard barrel on the H-S Precision HTR in 308, and was designed to shoot 168g SMKs at .500 or less, and it does. I load it with 168g SMKs and 44.5g of Varget, Fed GM210M primers in Lapua brass for 2710 fps. And its a tack driver, mine shoots in the .2 to .4s at 100.
Give it a try, its the same load as Federal 168g GM Match.
Mike.