How tight should I have my scope rings? Right now they are about as tight as I can get them just using my hands. Well the other day I noticed that the scope was further forward on my gun than I thoguht I had originally mounted, then I noticed what looked like tape coming out from under the rings. Well I tryed to pull the tape and it was actually shaved aluminum

What should I do? I am worried to tighten them down any more. Would lapping the rings or getting a reamer help at all? It would definitely make me feel better about tightening them down any more. Do I need a torque wrench for this?