SAAMI doesn't seem to make pressure specs available on line. From generally published data, the .30/06 cartridge appears to be loaded to lower maximum pressures than other cartridges based on the same case head diameter, such as the .308, .270, and .280.
There's no reason for this other than the presumed antiquity of some old rifles which may not be up to the strength of modern bolt actions.
As for the Model 70 . . . well, the same action is used for belted magnums, whose larger case diameters leave less steel around the chamber, and which have larger case heads which will increase bolt thrust. A "mere" .30/06 ought to have a bigger safety margin than any of these cartridges.
Unless damaged or defective, I don't see the action letting go unless you're way, WAY above pressure limits. And if you're "working up" to the maximum in small increments (as described in all the major reloading manuals) and paying attention to seating depth of your bullets (don't jam them into the rifling) then you'll see signs of excess pressure on the case long before you're in danger of blowing up the rifle. (The brass will start to "flow" before the gun blows up.)
For maximum velocity, as a very rough rule of thumb, the double base powder which requires the heaviest powder charge to reach maximum
safe chamber pressure will deliver maximum velocity.
For a .30/06 using 180 grain bullets, I've had good results with ReLoder 22 powder. Nosler recommends 61.0 grains as max in their manual, and Speer goes up to 62.0. Start around 55 grains, and work up carefully in 1 grain increments, looking for signs of excess pressure at each stage. I use Winchester brass and primer, with a Nosler Partition bullet.
I've never felt any real need to go above this published data, but if you do, you're on your own.