Ehkempf: I own 3 XR-100 Rifles and all of them are set at 45 inch/pounds on the action screws.
They all shoot extremely well.
I do not think I would be able to interject another variable like 100mstudent suggests - if I were to add to my regimen in seeking accuracy for a Rifle this additional variable (checking accuracy every 3 inch/pounds) along with seating depth/powder types & charge weights/brass/primers etc etc etc then I would NEVER get done testing - and maybe that would be an honest objective in itself - expensive but honest.
Instead I use a known to be successful torque setting for a brand of Rifle.
My Remingtons all seem to do rather well at 45 inch/pounds.
Best of luck to you with the XR-100 - I hope yours shoots as well as mine.
Hold into the wind
VarmintGuy