In real life, comparing the 30-06 to the 270 is comapring apples to apples. Take the best elk bullet for both, the 180 grain for the 30-06 and the 150 grain for the 270. The SD for the 30-06 bullet is about 271 while the 150 for the 270 is 279. Using these two bullets and the average velocities from the different manuals and you will see that at 400 yards, the 270 retains 1533 ME and the 06 retains 1475 ME. Would an elk feel the difference? I doubt it. Having used both rifles a lot, these results on paper seem to mirror the results in the field.