I have a 458 I play with and handload for.

Mac's comments are spot on.

The thread on the 400 Tembo discussing the Zim test and the 416 Rem mag is very concerning applied to the 458.Yes I can narrowly get 2150 with 500's but what about the pressure in that African heat?Could be a death sentence in a tight. Would you be better off to shoot a premium 450 grain faster at a lower pressure and have a safety margin so the rifle won't seize up?

Better yet as suggested make it into a 458 Lott to have less pressure..Kinda makes a 458 Lott more desirable running less than max velocity.

HMMM!!