Your 10/22 should have 4 small screws on the top of the receiver - if not (if its REALLY old) you'll have to have a gunsmith drill and tap the op of the receiver to add a weaver base. If you have the small screw holes you can just add the base yourself. A hint - use a bit of locktite to secure the base screws. Also - you can buy rings that mount right on to the screw holes on the reciever (they are a Ruger factory part) - but I have heard terrible things about them (that the recoil loosens them, and that your scope won't stay sighted in). You're best off going with the $15.00 weaver base.