You can use this set of Sun Optics USA Tac-X Riflescope Rings with the two most common scope maintube diameters: the basic rings fit 30mm scopes, and you can adapt them with the included inserts to fit 1" scopes. These 1.15"-thick rings are secured by six cap screws. They position the centerline at 1.575" above the bottom of the base. A recoil key keeps each ring solidly in place round after round.