Several posts on this board dealing with this issue. Use the search function to find them.

I have the Talley one-piece mounts and rings. If you want the best this is it. The entire mount and bottom half of the scope ring is machined from one solid piece of alumunum alloy. Two torx screws attach each side of the top rings to the bottom rings. It is super strong, stable, custom made for the encore and omega, and looks great as well. The fit and finish is top notch. The price is resonable too - $50.00 from Talley shipped direct to your door in 3-4 days.

Here's the link: http://www.talleyrings.com/al.htm