Ever since I got the newest version of the beta, the new destroyers don't fire their machine guns. They do aim them, but they don't fire.
There's also a bug where the cockpit can get "damaged" it will say "Part damaged: Cockpit" and the cockpit will start going red, if you have the "Show damage" function on and it will also play the explosion animation for the cockpit block, but the cockpit will remain fine. The cockpit blocks seem to get this "damage" only from hitting the ground.
@NathanMikeska I know, but the cockpit becomes red and, as I said, does also play the explosion animation(it doesn't get destroyed) when it hits the ground many times. I don't think this is supposed to happen. Try it, if you have time(with the cockpit being the only part of the "plane").
Yes the WW2 destroyers dont fire guns in sandbox, but they still do in the combat mission
The gun bug is a known issue and will be fixed in the final release. The cockpit is meant to be indestructible.