Mine was a 22" 1 in 12 twist and I wouldn't want to go any heavier than a #4 contour as well. I still actually have the barrel, I started and stopped with Big Game with bullets from 200 -275 gr. I hunted with the 200 gr TTSX at 3000 fps but didn't get anything, another good bullet was with the 250 gr Speer at 2750 fps. I decided my 35 Whelen was all I wanted but the 358 Norma is a very powerful gun and one of the better 35 cal cartridges out there. Big Game was very good but had it not worked out I had H 4895, RL 15 and H 4350 waiting in the wings.
The 200 gr TTSX is a nice bullet, I actually had it close to 3100 fps but figured 3000 fps was more than enough, it was an accurate bullet. The other bullet that I like is the 225 gr Accubond (works great in the Whelen and should be just as good 200 fps faster) both weights of Partition's are great of course and I bet the 225 and 250 gr Woodleigh's would be great too. Other than a specialised load of some sort I can't see going past 250 gr anymore and quite frankly the better 225's are excellent for anything in North America. If you can't kill it with a 250 gr Woodleigh, Norma Oryx or Partition I can't imagine anything heavier being much better.
Just my .02 and I hope this helps.
