cordite:
I respectfully suggest you will find the Lott case would have no advantage over the .458 Win Mag for shooting cast bullets.

Even on dangerous game IMHO. It has long been my contention that with modern powders (ADI or Hodgdon Extreme) and premium bullets (bonded-core or mono), the .458WM has finally become the cartridge its original designers intended all those years ago. At inception it was let down by 1950s powder and 1890s bullet design!
Jack Lott's flawed hunt in 1959 resulted in one man's answer at the time, but it is redundant today.

So I would suggest the .458 Win Mag.

Just my 2c worth.....