I’m not trying to rain on your ambitions on the .458 or saying that the 458 Win Mag is magically fast. The Howell was developed for use in std magnum length LA, it never really caught on. It did everything well and boasted better ballistics. It’s brass is expensive and you now have a wildcat, which is fine. What I am saying is 1,000s of cape buffalo and elephants have been shot dead very satisfactorily with a 458 Win Mag, that’s both hunter and PH. There’s probably no other single DG cartridge dedicated to cape buffalo or elephant that has been used more since 1956 on that type of game. Ballistics are a fine thing, same for barrel lengths and velocity, but you would not be handicapped with either in the field. Advantages, if any, is one has less recoil and an additional cartridge in the magazine. Putting it all aside the 450 Howell is a nice design, the 375 Howell has always been appealing. For that matter the 404 Jeffery fits on some std magnum LA. COL is like 3.53”. Good luck with your build.
