Is that just for the Trijicon RMR? I am planning to get one for my second 34 MOS. Both of my Burris Fastfire 3 sights mounted right up with the Glock with no problems.
It mounted right up, but the screws glock sends are too shallow that only a couple threads catch. Which would end up sending your RMR flying if you were to shoot with it extensively. I think it's an RMR issue, and mind you mine is about a year old, they may have rectified the issue. I sent someone else on the forum a set of screws, I don't remember who, but you can ask him since his was purchased later than mine.