Every gun is picky, some are less picky than others.
Do like the rest of us do, get your rifle on paper and zeroed to the best the ammo you have on hand can be, since you saying 350 yards, I would zero at 200 yards. I usually tend to go on the higher speed side with my initial hand load, seems I have less work after that on perfecting my load.
Then start playing for hand load recipes until you get the tightest group possible and stick with that load for that rifle.