Dear Folks,
Here is my thought. If you buy the 30-06, you have a great all around cartridge in regular factory loads. But, if you want to step it up a bit, can't you just buy the factory Light Magnum or Hi-Energy load for the 30-06, in say a 165 grain bullet, and virtually duplicate the performance of the 175 grain factory load of the 7 Mag? Also, if you buy the Light Magnum or High Energy load for the 30-06 in the 180 grain bullet, it virtually duplicates the ballistics of the 300 H&H Magnum. (I have personally chronoed and entire box, and it was within 25 feet per second of the 300 H&H factory load.)
I think that in this instance, the availability of these specialty factory loads makes the all-around 30-06 even more of a super all around cartridge, and simply does away with the need for a 7 Mag.