Experiencing jitter/stutter when mesh is parented to pawn and uses a separate lerp/rotator

I’m having some issues where parenting a mesh to a player character and having the mesh “follow” the pawn world rotation casues jitter/stutter.

I’ve created a tiny project that explains the issue (using 4.16.2).
It is accessible here: https://h.ma.pe/Stutter.zip

A screenshot of the Player Blueprint:
Imgur

A video of the stutter (compare the stable background with the jittery mesh)
https://giphy.com/gifs/xUA7aZPjM05W90eiCk/html5

You will notice the issue when moving the mouse around. Especially with fluctuating frame rate.
It is even more easily noticeable if you press “Space Bar” and let the automated turning give you an even pawn rotation.

If I don’t set the world rotation on the “GunParent” Scene Component it is solid as a rock.

Is there any way to remove the stuttering while retaining the delayed motion?
I’ve tried using the Spring Arm and it seems to have the same issue.