The 348 Winchester is much too large in diameter, 0.553" for the 348 at the case head vs 0.502" for the Rigby.
I've never shot a 358 Norma but would imagine recoil would be comparable. The 350 Rigby as originally loaded was on par with the 35 whelen, but with modern rifles the Rigby is essentially a 358 Norma in a different package.
Yes, forming brass was a PITA, but is an option. I came across a closeout deal on Bertram brass and bought 100 cases but as mentioned they are very soft and can't handle full pressure loads.
