If you want to take anything in the lower 48, then the 7mm Rem Mag is a wonderful choice! It'll give you a bit more of everything over your 270, but I don't know if it gives you enough extra to warrant it over the 270 (unless you just like it better). The 7mm & 270 are both fine guns for anything in the lower 48.

If you throw Alaska in the mix or even Canada's moose, you probably ought to start with at least a 30-06 (better yet the 300 Win Mag).

Just my 2 cents, but if your 270 is a good shooter that's all you need for deer, antelope, black bear, most hogs, even elk. If I were in your situation, I'd grab a 300 Winney or a 35 Whelen. They both will work on everything the 270 will, but add to that moose and bigger bears.