AR-15 Wobble Fix with Orthodontic Elastics

Have a nasty wobble in an AR-15 between the upper and lower receiver. The problem is, the lugs are pretty darn flush, so plumber o-rings around the lugs wasn't possible. What I needed was very slight rubber bands, and after a couple nights sleep, it dawned on me just how to go about it. I ordered some orthodontic rubber bands (do you remember seeing braces in school where teeth were connected my elastics -- ya, those) from Walmart. Leadrop Dental Orthodontic Rubber Bands, sized in 3/8", or, better known as: the Monkey ones. What is eerie about it after I wrapped one around the front and rear lug: zero wobble now. Tight as can be. I have ninety-eight to spare, so I put a dozen in a small ziplock, and stuffed that in one of the AR's cubbyholes in case the ones I applied get tired and snap.