Steve, if you want to know what pressure is for different loads in your rifles, there's a company in Arizona that does that for you:
http://www.arizonaammunition.net/Pro...20Services.htm
While it ain't cheap and requires you to send both rifles and ammo to them, it may be worth the expense to know reliably what your ammo's pressure is in your rifles.
Otherwise, someone may have an Ohler 43 system you could buy then do your own presure tests.