I had to go back through one of my old posts but found it!
"According to Nightforce, if using a 20 moa bases and medium rings .885, a 56mm will fit on a Sendero/light varmint contour."
When trying to decide on scope objectives for my build, I talked to nightforce and that is what they said! I went with badger rings @.885 which is their medium. However, .885 is nightforces low rings.