This reply is only life half a year old, which is like 3 days under modern time rules. Or is that 3 decades? Well either way, if it helps someone...
I'm going to presume you're seeing correction packets (writepacketdata/readpacketdata) which are what's actually causing the stutter. The default turret implementation doesn't properly account for the client-predictive/server-authoritative model control objects work under. In my experience, it's the deeply integrated client-server system of Torque that most people bounce off of, but that's also one of its biggest strengths if you're actually making a multiplayer game.
I was certain I'd posted about this at some point, and indeed if you journey back to the old GarageGames forums here is my fix:
http://www.garagegames.com/community/fo ... ead/130721
What this does is create a "render" version of the rotation variable and uses that to determine render orientation. This version can be safely modified by client-only code for interpolating between ticks, without altering the actual simulation variable for turret rotation (interpolation doesn't occur on the server, so interpolating the simulation rotation would put client and server out of sync). Follows the same model as every scene object having a separate simulation and render transform to store pos/rot.