I appreciate all the responses. I knew you guys could help me out. I used the chart on Leupold's site, but I didn't remember the lows being listed. Anyway, now that I know the lows and mids will work I'll have to see which ones I like. The bases I have are(from the package) Leupold STD Win 70 Rev. F&R 50023, Matte. Thanks again.