Difference is case (brass) capacity = more powder. Faster MV which lead to flatter trajectory and more energy across ranges.
I hear about the 7mm rem mag being a meat waster just haven't experienced it myself. I expect meat damage when I hit thebone/meat/shoulder, regardless of the cartridge I maybe using. Bullet, range, shot placement are all factors. Ie: I was chatting with a guy at the range who claimed his 300wm was a meat waster and too much gun for deer. He then went on totell a story about shooting a wt doe at close range last fall. The bullet he was using was a 110gr hollow point, that he claimed was hitting near 4000fps MV.
I asked why/how he thought such a bullet would perform and the conversation just ended
.
Just a suggestion based on your criteria of long range and larger then deer possibilities. Best of Luck