Okay, here is the turret.
Here are the two components, gun on the left, ring on the right.
From the rear.
So, to recap. The rail dockers and rail axis are all facing forwards, all in the same direction as the rail docker there in the last image. The Bobby AI is the block underneath the rail docker. The two cannon blocks are attached to the weapon computer, and the weapon computer is slaved to the ship core. There's a ship core in each section. The total weight for the combined turret is 3.5 mass. The ship it is docked to is about 115 meters long, and has almost 2 million power and half a million regen. No need for docked power, and there are no other turrets or docked entities.
The AI was apparently set up properly, or at least, it was active, since it gave me a red popup saying the AI has been deactivated when I went to undock the turret gun. Still no workies. No idea why. :|