Something I've noticed as I've loaded for my DR the past several years is that I need different loads when shooting softs and solids to get the same FPS and POI. I was finishing up my bullets for next month’s safari last night and again came up with the same results.
I like my .470 bullets to fire in the 2,135 fps range; that's where it shoots the best. With my 500 gr Woodleigh softs I get there with 87 grains of RL15; with my 500 Woodleigh solids I get to the same point with 85 grains. Why the difference?