Between the two, I think I would take the 35 Whelen,
but as both of these are Med bores on the 3006 case, you should have, the 9.3x62 in the mix as well, This would be my pick, and I do have a very nice husky, that hums along quite well, with a 250gr accubonds.
depends what you are trying to do, do you have a fast 30 cal.
seen as your name is FPS plus, pick the fasted one,
If you might travel outside of Canada/USA, then only the 9.3x62 is common in other areas. ie Europe and Africa, Australia etc.
I do have to wonder if sum bullet choices in the 338, might be a bit tough at reduced speeds of the 338-06, as that bore size, has sum real big fat cases, pushing at good speeds, ie the wby and lapua,