I stumbled across some Federal Ammunition reloading data for the 458 Winchester and Federal's 500 grain Trophy Bonded Sledgehammer. I do mean stumbled, pretty easy to find up through.308 info, but finding the .416 & .458 load data was a challenge for me.

24" Test Barrel

Alliant Power Pro™ Varmint, OAL 3.275", Fed 215
Fed Brass

Starting Load

69.5 Grains
2028 Fps

Maximum Load

77.1 Grains - Compressed
2213 Fps

Last edited by ldmay375; 02/03/24.