Here is a Part of one of my configs. What you are talking about is a Passenger Gun. A Turret would be the main gun of a tank, driver controlled.
Passenger 1 31 12 12 core -30 30 -10 10 WW2_MG_MG42ZB_1A FrontMG
GunOrigin 1 48 18 12
to Read as follows:
Passenger - The Position of the passenger
1 - No of the passenger
31 12 12 - X/Y/Y position of the Passenger
-30 30 - left/right boundaries of the gun in degrees, so this gun has a field of fire of 60°, 30 to the left of the driving direction, 30 to the right
-10 10 - lower/ upper boundaries of the gun in degrees
WW2_MG_MG42ZB_1A - name of the gun config file
FrontMG - Name of the model part
GunOrigin - the positiom of the gun (if not the same as the passenger pos)
1 - No of the passenger
48 18 12 - X/Y/Y position of the gun
so, if you want to have a 360 degrees gun, set the left/ right boundaries to -360 360, this will help
