Originally Posted by jorgeI
Tell you what, lads. I'll ask some of the older PHs at DSC about the 458 issue ( I KNOW for a fact the squib load issue with impacted ball powder due to excessive compression was real) and get back to you.


Couldn't find his account but Ganyana wrote about first hand experience with 458WM failures.

Here is the jist of it-

https://www.shootersforum.com/african-hunting/106065-ammunition-cheap-passing-legends.html

IIRC he was given a Parks 458 which did not penetrate and he finished the job with a lighter rifle.
I believe Don also wrote of an appy shooting an elephant with no results and the bullet was later found to be sticking into the hide without penetrating the skull.