I like Weaver scope bases for contenders, 4 holes and use loctite. You'll need to make sure the holes are really clean and no burrs before loctite and final tightening. I use Weaver "high" scope rings on mine, the ones with steel caps over the top-and lap the scope with a Wheeler Engineering scope lapper. The rings are Weaver #49042 in matte black, the bases are #92 Weaver.