I did the same thing, it seemed to me that the allen wrench that they sent with the site was the wrong size for the screw. I took a pair of vise grips to mine for the time being. I will pick up a new screw after this season. I also thought that the screw was awful soft when I went to tighten it with the vise grips, they may have used that screw on purpose as to not strip the aluminum of the site base/clamp.