So I picked up a volquartsen llv upper from a member here, the old style. I love it on my 22/45, but it has a small problem.

The rear sight walks over to the right after just a couple magazines. I tapped it back in place with a rubber mallet. Is there a set screw or anything in there or is it just friction fit? How do I make it stay put?

Thought I would get advice before I start tinkering with it.