ORIGINAL: Mossie
Use 165 grain bullets for longer range shooting. They hold up a bit better beyond 250 than the 150 grainers do and hold energy/penetration levels up.
I agree with this. My all-round .308 Win load consists of the 165-grain Sierra HPBT loaded to 2800 FPS MV using H380 powder. For really long shots, I would switch to the 165-grain Nosler Partition, as it will expand better at the lower velocities you get at long range. Believe it or not, the 165-grain Sierra HPBT is a pretty tough bullet!