This is one of those trivial bugs that probably isn't getting fixed for ages (if ever), but Ares Sentries, of all types, wiggle unless they're aiming to the left side of the screen (at the 270 degree point).

To replicate: Make yourself immune to the relevant damages, and sit near one. Regardless of your angle, unless you are to the left of the sentry the AI will wiggle it. The frequency and amplitude of said wiggle appears to be angle-dependent.

Interestingly if you sit exactly on the right side (90 degrees), the amplitude of their wiggle can line up with their weapon RoF (on lightning variants anyway) and it can sometimes make them aim incorrectly.

As the turrets that I spawn through PM's Godmod do not exhibit this behaviour, I suspect it is a problem somewhere in their orders, or the relevant AI code to those orders.

Attachment is a screenshot of a test where I am sitting directly to the right of a dual sentry. I have been there for over a minute, entirely stationary. The bug is causing the turret to wiggle wildly, and in this case it has compounded to an extent that the turret has fired wildly off to one side of my ship (this amplitude is rare, a turret doing this will usually only wiggle enough to consistently miss with a single gun (or hit with both regardless), but every now and then this will happen reliably.