Originally Posted by glockman10mm
Another thing about the two that is a consideration, is the 270 has a little more sectional density to it, which helps with penetration.
Not quite the whole story. In a given weight yes, just as in a given weight the 6.5x55 will have more SD than the .270. The 06 can meet or exceed the SD of the .270 with a heavier bullet and has the ability to go to heavier for diameter bullets than the .270 due to less pressure with the larger diameter and more case room.