I had a 350 Ribgy magnum, nearly the same capacity as the 358 Norma. Mine had a 1-14" twist, and was very accurate with 225 and 250 gr jacketed bullets, and 280 gr cast. With a 1-14 you'll be fine with bullets up to 280 gr, you'll only need 1-12 if you're going to use the 310 gr woodleighs.
As far as powders, I got better accuracy with RL15 and Varget than I did with H-4350. The most accurate bullet I shot was the 250gr hornady rn @ 2700 fps. The only downside is it's a soft bullet, and the small doe I took was nearly dcappitated with a close range neck shot. Alot of 35 caliber component bullets are desired for the 35 whelen and even milder rounds, so be careful what bullet you choose.
For the Norma I'd just get some 225 gr barnes tsx, launch them ~2900 fps and have a suitable load for all NA game to ranges further than I'd likely use such a gun.
