When I owned a 358 Norma, I necked up 338 Winchester Magnum cases to .366", then created a false shoulder for fireforming. I used the COW (Cream of Wheat) method. It saved my shoulder!
Oddly enough, I had a 3x Weaver scope on my rifle, which used a military Mauser 98 action. I hunted with it in 1991 in Colorado, but ended up shooting an elk with my other rifle, a 300 Weatherby.
