Attached Static mesh wiggle

Hello, please how can I get rid of this annoying wiggle? The sight is a static mesh attached to a skeletal mesh (weapon)
to a socket and when the weapon moves with arms the sight wiggles like this. But only when I have a lot of buildings and foliage around. When there are no actors on map it does not wiggle at all.

Video:
https://drive.google.com/open?id=1wGAzOvHDTrHIOKp6O26zz4vK0FY-ztX3

It appears the entire hand+gun is wiggling like that (cover the sight with some paper or something and look at the hand). Maybe track that part down first. Could be animation related or some glitch in your game or replication code.

No, only the sight is wiggling, the weapon might look like it because I am moving it like that, the sight is wiggling all the time on the weapon it is like it lags behind the weapon.