I am mounting a new 4X16 Vortex PST on a Savage 10FP with a one piece base. The base will be either a Farrell or the Factory one (EWG) what came with it. Which size 30mm Burris Signature Z-ring should I use Medium or High? I like the scope as close to the bore as possible, but obviously everything has to clear. What are your thoughts?

Thanks!