All the military specs I've seen show the 7.62's 22 inch barrel has about 100 fps less muzzle velocity for the same bullet weights as the 30-06 in 24" barrels. Both had 50,000 cup peak pressures.
Winchester used 308 loads in 24" barrels at 52,000 cup chronographed at 10 feet. Their 30-06 ammo had 50,000 cup.
Arsenals used 7,62 loads in 22" barrels at 50,000 cup chronographed at 78 feet.
SAAMI specs 308 velocity for 150 grain bullets from 2800 to 2980 fps, all with 62,000 psi or 52,000 cup. Evidence to me different powders were used.
Thousands of us are still confusing the old military and civilian use of copper units of pressure (CUP) differences with modern strain or piezoelectric sensors pounds per square inch (PSI) units. 51,000 CUP puts virtually the same force on the chamber walls as 61,000 PSI. Shame, shame on every ammo maker using a CUP system measuring peak pressure then publishing it as PSI. Unfortunately, this debacle will continue ad infinitum.