Back before CUP, psi was the deal. The factory loads for the '06 were published as being around 49,000 psi. When the .308 first came on the market, factory loads were published as being 55,000 psi.
Just guessing, but I've always figured that the lower pressure for the '06 had to do with all the old Springfields that were "out there". The GI loads were around 47,000 or 49,000, I disremember.
So, you load an '06 to 55,000 and you'll outrun a .308. Not enough for Bambi to notice, though.
You're from BATFE? Come right in! I use all your fine products!