Back in the 1970s, The local Gunsmith told me that the flip to the side mounts were not very good. As they could lose their accuracy. He also told me the one piece mounts were better than the two-piece mounts. However, I started using two-piece mounts in the mid '90s. As long as they're put on my guns tight enough I haven't had a problem.
So, maybe he was wrong about the flip to the side mounts. Anyway I just wanted to let you know what I was told.
