P.S., U.S. made 22lr tip off rings are 3/8" width, whereas the CZ are 11mm.
IIRC, the older 452 models were 11mm. Before I knew this, I tried the Weavers and they didn't work. Don't know if they still do but Burris made them to fit 11mm too. From this chair, the BKLs are the best option.