Also, if my memory serves, you couldn't get a powder to function at those levels in the early 1900's, but you could by 1920.
This is essentially it, as far as I know.
The 30-06 was still using powders from before 1910. Powders had improved by 1920, I found a quote that listed the 30-06 as getting about 3000fps with one of the new powders. But that's not what the factory loads or the military loads were.
So Savage was able to match an older powder and provide similar ballistics in a short cartridge.
