Since I own al of these calibers, I'd suggest the 416 in any flavor, Rem. or Rigby. Shoot the hell out of it, reload and find out how much more you can do with it. If after you whack something with your biggest baddest loads and you're not satisfied, then get a 458 Lott. The 416 I have is the Rigby in a Ruger RSM, I've found that if I load it with 450 gr bullets @ 2250 f/s, I really don't need any bigger caliber. But then again, the Rigby has the powder capacity to bump things up a bit. The only thing holding anybody back is how much punishment you can take when developing big loads. Of course, what's need got to do with anything, anyways?