Imperial sizing die wax and three steps to get from 458 Winchester Magnum to 350 Remington Magnum. Has anyone done that? It would cost over a $100 bill to get 50 cases in the Nosler brand. Remington was not in stock, seasonal only. Of course the Remington is way cheaper. I have paid for, unfired brass in 458 Win Mag, bought right in the past. Thus the idea of forming to my needs. I realize there is a process. A lot of trimming for one thing and fire forming on the end to get this stuff true. I think I will use my Corbin press for its precision alignment. TIA Rusty

Wouldn't 338 Win brass be easier to expand up?

Many years ago I did it wirh 7 Rem Mag cases but I don’t remember what, if any, intermediate steps it took.

I already OWN the 458 cases! Sorry to yell but no extra money spent is a good thing as I already bought the rifle, dies, but have the bullets, powder, and Primers. Rusty

Did you need to ream/turn the necks*** since the material came from down the body of the 458 cases?

***Not just for overall thickness, but to eliminate taper in the thickness from mouth to shoulder.

Form and trim dies are going to wreck over $100...if you haven't done so already. Using them will help eliminate case loss, as they form in steps.




And the anneal afterwards, to eliminate splits.

Going down with basic brass is a serious PIA; be prepared to lose some cases and have some wrinkles, real and perceived.

True, the case loss. I just don't feel like paying over $50 for only 25 cases. And even then not primed. Perhaps I'll keep up with the classifieds in a few places. If they are cheap enough I can afford some shipping. Rusty