Pieter-honestly I'd find a bullet that your rig liked and go from there. 400 yds isn't very darn far and it's awfully tough to find a bullet that wouldn't do well for you. I've not hunted the animals you mention but have a good deal of elk experience with the 338/06, 338 WM, 338 WSM and the .340 and and I'd just find a bullet your gun likes that you can buy when you want and go from there.
IMO either the 225 Noz Pt or 250 NPT would be incredibly hard to beat.
Dober
