FWIW the latest Alliant powder data publication with reloading data for their fine series of RL powders shows the pressure they experienced with the loads posted. It's a free publication at almost all gun shops.

Some data is represented in CUP and others is in PSI but all data is stated at a particular pressure.

As a general guide one might think of 60,000 PSI as equivalent to 51,000 CUP.

Further most (but not all) data for cartridges based on the .308 Win and .30-06 Spg are loaded to 60,000 PSI in this manual and most (but not all) belted magnums are loaded to a trifle more than that.

For those of us that think loading manuals are conservative we now can have a guide as to just how conservative it might be. Maybe that data has always been there and I didn't notice.....

ttt

Alliant's load data is also available online at:
http://recipes.alliantpowder.com/

And as a downloadable PDF file:
http://www.alliantpowder.com/guide/reloader.pdf

Home page:
http://www.alliantpowder.com/