Im in the process of applying for a 458 win mag for an upcoming African dangerous game trip, anyone got any advice on what kinda hurdles I may face from the police, Hampshire Constabulary by the way.
No. But I strongly urge that you get a 458 LOTT and not a 458 WINCHESTER if that is possible. The Lott is to the Winchester like, say, 22 Rimfire Long Rifle to 22 Rimfire Short.
The Lott will chamber and fire BOTH in total safety, for the Lott is no more than a slightly longer 458 Winchester will give higher velocity in factory cartridges or, if you reload, the same velocity at less pressure.
Anticipate issues involved with obtaining and practicing with s/p ammunition here in the UK. Some forces will not allow you to shoot these rounds - insisting that you collect ammunition on landing abroad.
Muzzle energy may make make range usage difficult - and as it exceeds the guidelines for 'dual purpose' safari/stalking calibres it may prove to be difficult to get permission for 'larger species' use on your own lands.
Having said all of that - it does vary from force to force.
Enjoy the calibre, suggest you only zero from a standing supported position as it can be a bit fruity for prone or bench use. Taking a world record flinch with you is not an ideal start to your trip!
A lot of places - Holland's at Northwood - where they do this have a post with a sloping piece of board on it to rest the left forearm on whilst zeroing in the standing position.
The board looking like it is one half of an arrowhead or a figure four. Indeed you might be able to get it zeroed at Holland's. I also think that "The Bog" at Minsterley has no calibre restriction on .458?