This is the first thing I developed on my own so please excuse any potential jank.
The standard form of tank aiming in shooter games is generally very frustrating when using a mouse and keyboard so developers of games focusing on tank combat created systems that allow you to rotate the camera freely while the turret catches up to it, this increases the players situational awareness and is much less frustrating then locking the camera to a slow rotating turret.
Here is my attempt to create something similar to the aiming system in tank games like AW and Warthunder.
I use a “turret target” essentially just an object to which the spring arm for the camera is attached, other than that you should be able to figure out the blueprint from the screenshots.
Oh yes I almost forgot to mention, ignore the section labelled “commanders sphere” it is related to the peculiarities of the armed vehicle that this system is integrated into and will likely not apply to your project.