" But the vast majority of them stated the numbers in print as "psi" value when in fact it was copper (lead) units of pressure or CUP (LUP)"
Ah so. Danke.
As far as "downloaded" '06 ammo, my recollection of factory data from '50s/'60s was that the '06 was loaded to GI specs of around 49,000 psi, while the .308 was reported at 55,000 psi. I've no clue about today's loadings.
I'm lazy. I've been using the same loads in my '06 as back in 1950 when I first started. They work just fine, so why bother to change?
I get deeper dings in my 500-yard steel plate with my '06 than friends do with their .308s. Not enough to get excited about, but that's consistently been the case. Kinda hard for me to not believe that the '06 is generally a little bit stouter than the .308.