Either will handle Black bear and deer with ease. I have had both for many years. If I could just have one, I would stay with the 30-06. OR I will throw the same wrench in and add a vote for the 280. It gives some edges over either the 270 or 30-06. Shoots about as flat at the 270 and with the 175 grain bullet, it comes right in there with the 06 for elk or moose. Load the 175 grain to around 2800 fps and nothing much is going to walk away. I think the 280 is the most under rated caliber out there.