To me the reason to go to the 358 Norma is to push the 270 gr Northforks or 280 gr A-frames 2500-2600 fps. To me that's even steven with the 375 H&H regarding same sd's at the same velocity.
I can't see going heavier than 250 grs in the whelen as "premium" bullets offer plenty of penetration, and I wouldn't want to be launching them at 2200-2300 fps. If a 250 gr X, northfork or a-frame at 2400-2500 fps doesn't do the trick, it wasn't the bullets fault.
