I have the Browning bases and high rings on mine but for my Tasco 3X9 the rings are to high IMO. I think when I take the scope off and have a trigger job done I will go back with either low or med rings. I may also get a better scope but it wont be anything with a large obj. so I should still be able to go lower than I am now. How large is the obj. on the 12X. I'm thinking you may have to use High rings.
BruceP