The Bushnell one my tikka t3 lite moves forward after ever few shots ,I bought a better 1 piece ring set and still moved forward. Read somewhere that all u use is a lite coat of liquid electric tape . Did it and it has not moved since. Right or wrong it worked. I figured this out 2 weeks before my trip 2 years ago. Kinda forgot about it till I read your post. I put a little piece of sticker in front of front ring and you could see the gap growing after ever shot. Has not moved at all since the liquid electrical tape deal.