I’m not trying to talk you out of re-boring your .30-06
Neither am I, if 225s and heavier are the end objective.
Reboring a 30-06 to .338 just to shoot 180 or 200s however, makes as much sense as reboring a 270 to .308 to shoot 140s and 150s. It’d be retarded.
Obviously the original poster isn’t, since he asked about 225s to start.