I bought a pair of Grand Slam top mount bases and rings almost two months ago. I mounted the bases on my Savage 10MLII with no problems. When I tried to tighten one ring up on my scope it felt like stripped threads. Come to find that one hole in one ring was over bored and shallow threaded. Sent them back to Weaver and waited 3 weeks for replacements to arrive. Had same problem with replacements. :x Waiting to see if Weaver goes three for three. :wink: I don't recommend them unless you like being frustrated with faulty product. In the conversations with Weaver they never admitted to having a production or quality control problem. :?