Anything other than  controlled load against load testing, is anecdotal crap. Testing  correctly (scientifically), will require a lot of repetitions and a lot of testing. It will require a large  supply of shot to shot consistent test media changed after each shot.  Testing  should be of an impact velocity at a normal hunting  distance- IMO, something  like 100 yards. Can't have factory ammo adjusted to expected velocity at a set range so have  to set media at  that distance  and shoot into it. Can use reloaded  ammo adjusted to average factory assumed muzzle velocity then loaded  for expected impact velocity at the 100 yard distance with media test distance at about 5 yards from muzzle. This  is what I  do to test bullets. Reload to expected impact velocity at about 100 yards and  shoot into media  about 5 yards from muzzle.  Select a decent sample size for each  load- maybe  3  reps. Take consistent measurements for wound channel estimation, wound channel path and depth of penetration. Pick 3  common factory loads for both the  270 and 30-06 with different common bullet  designs in  different weights within the  common weight ranges for both calibers.  This is a  lot of shooting, a lot of media resets with a  refresh of  media after  each shot and  a lot of measuring. It will  take a  lot of time. Post results. That  will  come closest  to  answering the basic  question  in the  OP. Of course you have to compare  apples to apples when reviewing  the data. It should be  obvious a slow 220 gr tough  bullet out of the 30-06  is going  to penetrate a lot more than a fast 130 gr  frangible bullet  out of  the 270.  But closer apples to apples...  might be the penetration of a 150 gr 270 bullets of a particular design compared to a 180 gr 30-06 bullet of  that same design. Three reps of  each  load and bullet weight  and design for both  calibers should be  statistically valid enough to prevent too many "ya buts". 

    The arithmetic indicates a lot of shots 
 
3 shots 130 gr  270 Bullet X
3 shots 130 gr  270 bullet Y
3 shots 130 gr  270 bullet Z
3 shots  150 gr  270 bullet X
3 shots 150 gr  270 bullet Y
3 shots 150 gr  270  bullet Z
3 shots 150 gr 30-06 bullet X
3 shots 150 gr 30-06  bullet Y
3 shots 150 gr 30-06  bullet Z
3 shots  165 gr 30-06  bullet X
3 shots 165 gr 30-06  bullet Y
3 shots  165 gr 30-06  bullet Z
3 shots 180 gr  30-06 bullet X
3 shots 180 gr  30-06 bullet Y
3 shots 180 gr  30-06  bullet Z
= minimum  45 shots
*add 3 shots for each different bullet design or weight tested