Ya may want to re-check the ballistic tables for the 150 gr .270 and the 150 gr .30-06. Reload manuals and tables from various ammo makers show nearly same velocity for both. With certain hand loads there can be differences of up to 150 ft/sec between them. I agree that the .30-06 has more potential for a bit more powder and a bit higher velocity due to the shorter bullet of the 150 gr .30-06, but they are usually the same velocity when loaded.
You'll get the same energy transfere when you throw the same grain, shape, and velocity of bullet regardless of bullet diameter. The difference in these situations is sectional density.
With reloading you certainly can make a 150gr 270 shoot with a 150gr 30-06. What you can't do is make it keep up when you go after the heaviest loads. Not possible because of the bore size. You'll notice in cartridges with the same parent case that the larger the bore size, the lower the pressure at a given charge. The difference isn't great but exists. where the advantage goes to the 270 with the 150gr bullet is that it is a heavier constructed bullet with better ballistic qualities. Those ballistic qualities exist because of the length of equal length bullets. You'll find the same is true with all cartridges based on the same parent case. The bigger bore reduces the pressure somewhat.
You'll notice that the 130gr bullet in each has about 100fps advantage in the 30-06. The 270 is generally said to reach 3200 fps and may well be able to but then the 30-06 will do 3300 fps if pushed. In either case, pressure must be suspect. The same 130gr bullet from a 25-06, wildcat bullet's, won't get 3100fps without a very long barrel and high pressure.
keep in mind that, all things being equal, as bullet dia increases, pressure decreases.
Don I know this is an old post, and I'm not trying to argue, but I still have to disagree with these numbers. I was referencing both the .30-06 sprgfld and the .270 win both using 150 grain bullets and both loaded to their max. Under these circumstances both cartridges perform pretty near identical to each other. I'm getting my information from both various factory ammunition ballistic tables as well as various reloading manuals.
With all due respect I have to disagree with the figures you stated above. A .270 win with a 130 grain bullet loaded to max pressure out of a 22 inch barrel will only safely give you a bit under 3100 ft/sec. A .30-06 with a 150 grain bullet can not safely give you 3300 ft/sec. In fact a 150 grain bullet out of a .30-06 is typically maxed at around 2900 ft/sec and more like 2850 ft/sec is typical. To get 3300 ft/sec out of a .30-06 you need either a longer barrel (longer than 24 inches) or a much lighter bullet. Something like a 110 grain bullet loaded to max in a .30-06 will give you around 3300 ft/sec, but a 110 grain .308 diameter bullet is not your standard biggame hunting bullet in this cartridge. If you check the numbers in any reloading manual you will see. I reference 22 inch barrels here since most modern sporters are barreled with 22 inch barrels and not the 24 inch that many ballistic tables derive their data from.