A little oddity, but a bug nonetheless
- Equip and Rail dock a Turret Gun to a base
- Delete the rail docker that is in use, and replace with a block such as power reactor/capacitor
- Flip to flight-mode, and look at Weapons menu. The Power Reactor/capacitor will now "occupy" the rail docker slot in the flight mode weapons bar
Have yet to test further, but this has happened all the time with me under those steps to say its reproducible.
EDIT: Didnt notice a specific Rails/Docking category. Have changed to it.