Dave, you should not have a problem with leading if you cast hard, and use a gas check design, with gas checks. I cast a 170 grain Lyman GC (linotype) for my 30-06 and drive it around 2300 FPS with no leading at all.
I also shoot a 50 grain Lyman (also linotype) in my 22-250 at 2000 FPS with the same results. Some powder fouling and a little melted lube around the muzzle but Hoppes takes care of that very nicely. To be perfectly honest the rifles are easier to clean than if they had been fired with FMJ's. The powder fouling and lube cleans much easier than copper fouling.