I've never seen one approach the velocities I get with the 30-06 loaded to 63k psi in a modern bolt action.
RidgeRunner, how'd you know the pressure was 63k psi; what did you measure it with? SAAMI's pressure limit for pressure transducer measurements on the .30-06 is 60,000 psi and its based on the limits of the .30-06 case. If you really had 63,000 psi, then it's quite possible standard average peak pressure loads for a .308 won't approach what that pressure produced.
Note that modern bolt actions will handle that much pressure for any cartridge. Some .308 Win. factory ammo has pressures at 63,000 psi as its case design's rated for 62,000 psi; the SAAMI spec which also has 66,000 psi for a maximum sample probable mean pressure.