If you are talking all short Mags. My pick would be the 270wsm. The 7MM and 270 versions would serve pretty much the same tasks with pretty equal performance. The 300 of course would give you more bullet weight range and more ME. One down side I have heard about the 7MM SM is that you must seat the bullets pretty deep and therefore loose powder space. The 270 SM kind of fills a nich that only the 270 Weatherby Mag fills. They are hard to find and expesive to buy and shoot. You would also be well served by the 270 Winchester. I don' t know what you plan to hunt. The mags are really not my cup of tea.