They're awesome mounts. I have several. The only issue I ever had was that I broke one of the ring studs/bolts. I contacted Bobro, they sent me a return mailing label, and shipped me a new one, once they received mine. Great customer service. Even though they are quick release, I rarely take mine off. But when I do remove them and re-attach them, they keep their zero within 1/4". Just watch your ring height if you get a mount with a 20 MOA cant. If your scope base already has a cant, the objective bell on your scope may hit your top rail, or barrel.