Re: what is the best 308 ammo
If it factory ammo youre talking about, the federal gold medal match is hard to beat in either 155, 168 or 175 SMK.
If it is hand loads youre looking for, VARGET, 4064, BENCHMARK and RL-15 are sure bets for powder, 175 SMK, 178 AMAX, 190 SMK are also very good match quality bullets well suited for your twist.
Long range shooting is a process that ends with a result. Once you start to focus on the result (where the shot goes, how big the group is, what your buck will score, what your match score is, what place you are in...) then you loose the capacity to focus on the process.