458 winmag and black powder/substitute

[trauma1]

Allright, so I will try this here. Looking to see if anyone has any experience loading the 458 winmag with blackpowder/substitute. Recently acquired a 458 winmag and blackpowder substitute is easily obtainable in my area. Any loads, suggestions, etc greatly appreciated. It is a #1, looking for deer/hog medicine with a 405gr boolit.

[waksupi]

I did some with black powder, basically made a .45-70 out of it. Shot well.