I have a soft spot for the Madcow rail buttons that Apogee sells. I am always paranoid that a screw alone will pull out of the airframe, especially with cardboard or the newer thin wall fiberglass. These solve that. After a few uses rail buttons can get a bit scrubbed out. These are also easy to change over without needing to glue anything again.

https://www.apogeerockets.com/Build...3 l4og6ojqhde4