The 300 win mag goes 300fps faster which generates 700 ft/lbs of energy. (Those numbers are close, but rounded...using 180 grain bullets out of both guns.)

The 300 win mag also shoots 6" flatter at 300 yards.

I know that the 30-06 is more than capable of killing all 3 animals. However, if I were to go on a "once in a lifetime" moose/elk trip...I'd opt for the 300.

That said, the 30-06 is the best deer gun around in my opinion.

So I guess I'd buy 2 different guns! LOL