I just mounted a Pulsar Thermion 2 XP50 thermal to a Tikka T3x Lite 6.5 CM using a Mountain Tactical picatinny rail and some Vortex Precision 30mm medium rings. The Vortex Precision rings were crazy expensive ($150), but I had a Cabela's gift card someone gave me and they happened to be the only lightweight ring set in stock at the store. The Vortex precision rings are probably the stoutest lightweight aluminum rings I've ever seen. They have really large T25 screws on both the rings and the mounting screws that have the most thread engagement I've ever seen. Considering the Thermion weighs in the neighborhood of 32 ounces, I think overkill in strength is in order, even on a light recoiling 6.5CM.
