G'mornin'.....up for sale is a set of Sako/Tikka stainless extended bases to fit long action calibers and "blue steel" low rings to fit 30mm scope tubes...the quality/machining is impecable and highest order $60 for the bases $60 for the rings $110 for both shipping included regardless of purchase The bases will accept any Sako/Tikka Optilock ring combination of any scope tube diameter and scope mounting height. Used on a .300 win mag and they are SOLID...the design is pretty smart and does in fact allow scope removal and re-installation without need to re-sight. I believe this is a valuable feature in the field if things go bad optics wise, need to put on a spare scope and does in fact work! After removal and re-installation to evaluate, the point of impact was off .75 MOA @ 100 yards. I would still (and did) re-sight if time and location permits! "blue steel" 30mm low rings with self-aligning polymer ring inserts and 4 screws per ring cap grip the scope with no induced torque or pinch on the tube. No need to lap rings or worry about tube/scope damage. The scope is gripped by the entire inner ring surface area and solid. This base/ring combination has a scope center height of approx. 30.5 mm above the receiver I have a Nikon tactical 2.5-10 with 44mm objective and there is approx. 5-6 mm gap between the objective bell and the barrel. It is written by many that this combination will allow a 50mm objective.