Weigand Mount,
The first time I installed the Weigand mount I did have an issue with movement, but this was my fault not in the design of the mount. I was in a hurry to get to the range and sight in for the next days squirrel hunt and didnt have any blue thread lock compound for the dovetail insert screws. I just tightened it down, added the mount and put a BSA RD30 dot sight on the pistol.
Fired about 250 rounds, went home and did a quick wipe down and got things ready for the hunt. Next day I missed every shot I took, stoped back by the range and it was hitting all over the place. Yep, insert screws had worked loose because I didnt add thread lock.
I have since installed the mount correctly, Weigand instructions includes adding thread lock to the insert screws and base screws. No more problems and its deadly accurate with the cheap 1" Target Sport sight.
squirrel-shooter