It never fails to amuse me what some guys will do on their guns. Dude was talking about the military side sling adapter on the Colt 6920 ( M4 carbine). This is a gun that is made for hard use. Rarely do they even leave the factory looking pristine, In fact they are semi famous for not being. They are combat guns. Meant to be used hard. The side sling adapter is loose for a reason. It can be swapped from left to right. This guys advice is right up there with the O ring around the front upper take down lug to stop wiggle, zipties around KAC rail panels so they are tight and butting stick backed velcro or black tape over the brass deflector because those jerks at colt made the gun where brass hits it when you shoot and messes up the fit and finish with brass marks! I censored the group name out because it is a very good group otherwise full of knowledgeable and serious experts and collectors. I don’t want anyone to think this is normal for said group or to spread can shim dude all over the web.