I,m no guru on the subject ,but heres why I chose the 458 Lott (my chamber is actualy closer to the 458 Watts)
With a Brno 602/CZ550 ,it will fit 5-6 in the mag and one in the spout. Wider cases usualy hold 1 or more less.
I can get 2300 fps with 500 gn bullets with NO presure signs in an uncompressed load (84-85 gns 2208/Varget). These cases have only been neck sized the last 7 or 8 times and still chamber easily.
If I am in Arnhem land or Africa and the air lines lose my ammo or if I run out or misplace it ,458 Wins can be used and these will be easy to find ,if I cant get any 458 Lotts or 458 Watts.
Since the case is not too big ,it is easy to slightly down load it for 400 gn woodleighs or 300 Barnes for smaller game so I can use 1 gun if necassary.