I mounted my HHA single-pin slider to my new rig.... and it sounds horrible. I refuse to ditch the sight, so what do I do? Teflon tape? Loc-tite?
Something is loose. Tap around without shooting it and you'll probably find it. Does it have a light on it?
Double check all bolts first. Something is most likely loose. Try to figure out where the noise is coming from. It might help to take the sight back off and tap around on it, trying to reproduce the vibration. If nothing else, call HHA and see what they say.