Try this!
Ok, first your chamber and bolt must be clean and dry, no oil and no grease. Remove the top cover and recoil spring, you?ll have to remove the extractor from the bolt (check the forum) so only the bolt face touches the gauge and not the spring loaded extractor. Now carefully put the go-gauge into the chamber, using light thumb pressure on the carrier; push the bolt home, keeping an eye on the tail end of the bolt at the rear end of the carrier. As it moves forward it will extend out and rotate into the lock position, it should only take a light push to lock it up. Now remove the Go-gauge and put the No-Go gauge in, again push the carrier forward and see if it will lockup with only a light pressure, if it does your screwed, to much headspace, if it won?t lockup your fine. Push a little harder but don?t push too hard or you?ll mess up the gauge. Still won?t close? your great.
