I've owned seven Pedersoli 45-70's to date. They do not advise using them at Ruger #1 pressures. I listen to the manufacturer on this issue. Internet advice is free, and wildly diverse. This is the worst place in the world to get advice on medical, legal, safety issues. Before going and loading your Pedersoli to those levels, do a sanity check and see what the manufacturer recommends regarding safe pressure levels in any particular gun. If you're lucky you still have ten fingers and two eyes....try to keep all of them.