What I meant by pushed forward is when you mount your base, you should push the base as far forward as possible within the actual rail. The front of the lugs of the mount should be contacting the back of the rail slot in front of them. (Hopefully this makes sense. Essentially, where ever on the picatinny you want your base - just make sure you push it forward until it stops within the specific slots, then tighten the base.)
^ Doing this means that when the recoil of the revolvers rocks back that the base / rings will rock with the revolver, rather than the revolver recoiling and slamming back into the rings / base.
Also - maybe it is just me here, but your serial number should be facing down. In the one picture, you're using your windage adjustment as elevation, and elevation as windage.