I did try a set of the Crimson Trace's for my G27. They worked okay until I started shooting. Then the laser's point of aim would shift and the "red dot" would gradually climb. I dunno if I have a bad set or they couldn't take the massive recoil of my .40. I have heard other guys talk about them on bigger glocks and they seem to have no problems no matter what the caliber. I honestly think that didn't work because of the gun being so small and that much recoil, because I could re-align them and they would work for a magazine or so..then the laser dot would drift again. Umm.. dunno if that was an issue of mine only or not.. But, other than that they are cool and I know other people like them.