If you never plan on hunting anywhere other than those type surroundings ( 50 to 75 yd-100 max) you would be fine with a 30/30. If you're thinking a 270 WSM would bust brush worse than a 30/30 I couldn't agree with either one. Neither are going to "bust brush" worth a darn. I sometimes hunt with a 45/70 and I'm not going to take a chance on it busting it's way through anything if I can't get a clear shot. If you pick your shots, either would be fine.
You sure you can skin Griz pilgrim?
Skin this one and I'll bring you another!