Weaver Steel Lock Mounts allow you to adjust the eye relief on your favorite scope. These solid, all-steel rings allow you to move your scope forward or back for optimum placement. Two straps and four screws provide added gripping power for these lightweight, all-aluminum rings. Thumbscrews allow for quick detach. Weaver rings can handle any scope-mounting need. Whether you're looking for our classic Weaver's original cross-lock Top Mount, windage adjustable or dovetail extension rings; we have many great options. These rings are available in a variety of choices including aircraft-grade aluminum options or Grand Slam steel, and many more. The ring straps are supposed to come in contact with the lower mount during tightening. You should alternate tightening a little at a time and to tighten no more than 20in/ibs. There will be a gap of approximately 1/16? on both sides of the straps. If you tightened just one side at a time then one side of the ring straps would be tight to the lower mount and the other side would have approximately 1/4 inch gap on just one side. The gap needs to be equal on both sides. And if that is not the case then it probably needs 30MM rings.