You're gonna love that round! I've had the pleasure of shooting Ken Howell's custom Mauser 450 Howell.
Power level seems to be halfway between a .458WM and a .458 Lott.
You ought to see what it does when you hit a 100lb whitetail doe just behind the shoulder @ 75 yards! She moved after the shot...straight up in the air, turned over, and hit the ground on her back. I thought Miles was going to have a stroke he was laughing so hard...
Might give your .460Wby a run for it's money as a jackrabbit gun.
Ed