I want to put a different scope on a Savage. Presently, it has an old Weaver 36x with 1" tube, Farrell base and rings. I suspect the Weaver has internal problems. I want to put a newer Leupold 30mm tube scope on the same Farrell rail. Farrell rings are expensive, just to test the scope. I would prefer to buy cheaper rings to fit the Farrell mount. Are all Picatinny rails the same? Any suggestion on where I can find cheap 30mm rings to fit the Farrell rail.