168 Gr Sierra matchking
139 gr Hornady Interbond or SST (Almost same BC as .308 168 SMK)
162 gr AMAX
Berger 168 and 180
Speer 145 gr match
For 500 - 600 yards, I'd look at the 139 - 150 class bullets, you can reduce velocities to 2600 - 2700 FPS, extend barrel life and shoulder life. These bullets have pretty darn high BC's and you don't have to push them at magnum velocities. Save the big powder charges for 800 - 1200 yards.