Buffalobob - you should have tried my Model 70 Palma rifle before I sold it... I never did hunt with it, with the sights installed. But did shoot some steel silhouettes and of course did a bit of mid & long-range prone shooting as well. Was pleasantly surprised that the round apertures front and rear did so well on the silhouette targets - just center the steel ram in the forward aperture, hold hard and squeeze. Boom. Clang! That rifle had a 30" Krieger so muzzle velocities were pretty impressive for a .308 Win. With a scope it did some rock-chuck duty...
Back to the OP - I limit my .308 Win to about 600 yards. It works well there, and I shoot it well to that point. There are cartridges that are much better at longer ranges, not that the .308 can't get it done out past that - just that there are obviously better choices w/higher velocity and higher BC bullets.
Regards, Guy