The accuracy of my Vortex suddenly went south. A normally very accurate bow started slinging arrows hither and yon with no pattern. Everything was tight so I started looking closer. Turns out some lacquer (I use it to crest my arrows) had rugged off on one side of the channel and was causing the problem. Cleaned it off and lubed the rail with Jig-A-Lube and I'm back in business. Whew!