you can shoot anything you want in it. the p series pistols were designed to shoot any and all loads. the original p90 45 was designed as a 10mm gun. your 345 is also capable of pressures in the 10 mm range. page 12 of the ruger manual states -
The Ruger P-Series pistols are compatible with all factory ammunition of the
correct caliber loaded to U.S. Industry Standards, including high-velocity and
hollow-point loads, loaded in brass, aluminum, or steel cartridge cases. No .45
Auto ammunition manufactured in accordance with NATO, U.S., SAAMI, or CIP
standards is known to be beyond the design limits or known not to function in
these pistols.
i would suggest going to a slightly heavier spring from wolf if you plan on shooting "really" hot loads.