No way, will a 4X scope be under powered for a 30-06. first off the ONLY disadvantage you'll have is at the range trying to make itty bitty groups.
I have a savage 30-06 with a 4X and duplex reticle. Out to 300, 4X, on an elk will be a dream. When I sight 180gr bullets 2" high at 100yds, I can place the section of the bottom half of the verticle reticle (does this make sense?) where the fine cross hair gets bigger, on the center of an 8" steel plate and ring it every time. Built in range compensator.
Actually it makes for one less thing to go wrong. Imagine the feeling of sighting in on an elk at 50yds in the tight woods, only to find the scope is set at 9 or 10X and you CAN'T FIND HIM before he moves. It happens more than folks will admit.
With that fixed 4X you'll have a great field of view and fast acquisition. I can print 1 1/2" groups at 100, 3 1/2-4" at 200 with a 4X, and definitely Keep them inside 8" at 300. That's about half the size of the heart lung area of an elk.