I used a .338 Wmag for many years and killed a bunch of moose with mine. I have never seen a better round for heavy game. When shot they basically don't go anywhere. But having said that I moved down to a 7mm rem mag a couple of years ago and guess what they drop just as fast! Your 3006 is not much different than a 7 mag so I would say shoot the one that you shoot better. Oh, and if you decide to use the big one I used to drive 250 partitions (which is what a .338 is really designed to do) at 2700fps no problem with a couple of powders.