RE: 7mm vs. 30-06
stubble - 170/175 - same shiit, I don't use 'em. Obviously you can also use partition bullets, etc. with the same construction and sectional density in a 220gr. for the 30-06, so the weight makes the difference.
"as if it was necessary"??? - I guess you've never seen a big bear...
Have you ever heard of inertia? If you use two bullets of the SAME construction, the HEAVIER bullet (125.7%) is going to penetrate further and do more damage than a lighter bullet. That is a FACT.
If you don't understand that concept, stand there and have two guys run into you at full speed, one at a time - a 175 lb receiver, then a 220 lb running back, then tell me that there is no difference...
Use what you like, but get it right.