Mounting a scope on a Ruger PR is like mounting one on a flattop AR. You're gonna need something. Nightforce High or X-High rings would work, but I'd go with a one-piece mounting system. The Nightforce Unimount is a great one.
I ended up with a Team Warne 1 piece on mine. Would love that NF Unimount, but dayum...$$$$ lol
ETA: Oops, those aren't that bad. I thought that was the 1 piece RTZ mount you passed around a year ago in an optics class that was $500...lol
I see the Unimount is only around $225.