I have a rifle specific built for the 155, with a 95 Palma chamber cut. The throat is shorter to optimally seat Sierra 155 Palma projectiles. As expected, the rifle shoot superbly with these bullets and I get very high velocities out of a 30” barrel. Around 2950 fps. (This is a very hot load, be careful if your chamber is not tight cut to allow, work up slowly looking for pressure)
I have no opportunity to shoot 1000 yards so I cannot speak to the effects. However, I have used to good effect at 600.
Nowadays modern projectiles have been coming out with super ballistic coefficients. I settled on 168 Berger Hybrid for my match projectile. Better increase in BC, yet still retains a ton of speed. If ever I can shoot 1k this would be the round I use.
Problem is .308 case is too small, if you go heavier than 168 you start losing the ballistic advantage of the more massive bullet because of the decrease in velocity.
If there is no requirement to use .308, 6.5 Creedmore and other variations, have much better external ballistics for long range shooting.
IMO