Originally Posted by pusangani
loosen the screw a bit n see if it moves back and forth smoothly, then tighten it up to the point that it still works
Also make sure that ur rear sight is seated correctly and that the top of the bbu is mating correctly with it.
To my understanding if the rear sight was not mating correctly with the top of the BBU that would mean the BBU would be pushed down and it wouldn't line up with the rails. There is a small gap between my rear sight and the slide, but the BBU is sitting flush with the rails so the sight probably isn't the issue.