I don't really see a reason to buy another gun to hunt antelope with when you have an 30.06. Load some 130 or 150gr. bullets and your trajectory will flatten out like you are wanting. Sure, the 7mm will have a long flat trajectory and is a great round for flat shooting at long ranges, but it comes at the expense of recoil and you have to spend $$$ on another gun. The 270 will be pretty close to the 7mm out to about 300 yards, then the 7mm leaves it in the dust. But the 30.06 is a pretty good round to do what you are wanting anyways.