3DOGMIKE,
THANKS FOR THE DETAIL ON THE EVOLUTION OF THE WINCHESTER 45-90 CARTRIDGE.

In my own experience, I found the 300 grain Winchester cartridges at 1850 fps to be adequate for deer, elk, Nilgai, etc in the USA.

For Africa we had 450 grain NF loaded to 2150 fps by Grizzly cartridge. Those shot through ele heads, buff, etc from my 1886 with 26 inch barrel.

My only other .458 big bore is a DR that has not yet been to Africa.