I would call Marty Bordson at Badger Ordnance and he will tell you exactly what rings will fit that scope and barrel contour. He will also sell you the correct rings. There are other good sources but Marty is the man. If you spend that kind of money on a Nightforce you really should put it into the best mounting system - Marty's number is (816) 421-4956. He is a good guy, he puts up with me on a regular basis /ubbthreads/images/graemlins/smirk.gif
I would also talk to him about a 65 in-pound torque wrench for properly tightening the side nuts on the Badgers and the stock bolts in your rifle - he sells a kit with both attachments. (Believe it or not I am not a Badger salesman...).