Now that I know you are punching 600 yard paper, I would use the 155 Palma or AMAX loaded as fast as you can get accuratley. The 155's are a good comon sense bullet for the 308 but shooters seldom use a twist that is optimum for the 155. From your 25" bbl in 14x I would expect around 2900-2950+ FPS which is very good. If ussing a 308 winchester try RL-15, VARGET, or IMR4064 in that order. The 155 Lapua Scenar might stabilize in your barrel or might not. I havnt tried that bullet in a 14 twist. If it stabilizes and you get good accuracy it will have the best BC of the 155's. An honest .495-.510. With your twist and bbl length I would guess it to be around .500-.505.
Good luck!