Wow, thanks for all the responses guys -- what a great forum!

Of course I would never mean to imply that the 458 isn't "enough gun" to fell any beast roaming Africa (or any other continent) -- even at "only" 4000 ft. lbs. I was just curious to know if factory loads had improved since Boddington's write-up. According to the "history books", 5000 ft-lbs has stood as the definitive measure of stopping power since the black-powder 8-bores of yore.