I reload so different experiences.

Federal Gold Medal and Black Hills match are some of the more accurate ammunition. Lapua is too but harder to get most of the time.

155 vs 168 is not much difference out to 600yd. I have used Berger and Hornady 155's (Fullbore and ELD match). Both did ok at 1000yd (close to MOA) but you really want heavier bullets at that range, eg 175's with Sierra's being one of the better ones. FWIW the SMK's are used in the Federal loads.

There is a long and emotion filled thread on factory 308 loads elsewhere in here.