CAUTION: The following post includes loading data beyond or not covered by currently published maximums for this cartridge. USE AT YOUR OWN RISK. Neither the writer, The Firing Line, nor the staff of TFL assume any liability for any damage or injury resulting from use of this information.
CUP is not psi. 60,000 CUP would likely be around 70,000 psi. Not proof pressure, but getting up there and bound to wear a throat out.
The current SAAMI standard calls for 46,000 CUP maximum average pressure by copper crusher and 51,000 psi maximum pressure by the conformal type piezoelectric transducer. The CIP standard for the channel type piezoelectric transducer is 3800 Bar or 55,114 psi, which Vihtavouri powders will use as the limit in their load data. These pressure limits are likely a nod to the fact a lot of the 1896 Mausers are getting pretty long in the tooth. Your Ruger should be able to take more if the brass holds up OK.
There are several ways to estimate it for the Ruger, but buying and calibrating a Pressure Trace is the best approach. Figure that with many rifle powders a very crude guess is that since your pressure ratio target is 60/51 you can probably increase the charge weight by about the square root of that or around 8.5% to get from a standard load to your objective, but the cases may limit the matter, so work up slowly while watching for pressure signs.