Shooting from a space ship


I’m having a hard time figuring out how to do this: I want to shoot bullet like objects from weapons attached to a space ship. The weapons have a location where bullets should come from. Each time I press the shoot button only one bullet should come out per weapon and the weapons are not extremely near together. The ship has a RidigBodyControl with a HullCollisionShape at the moment, and my bullets have a SphereCollisionShape. If my ship moves forward and I press fire, nothing happens, because the bullets instantly collide with my own ship. I tried spawning them a little bit further away from the ship, but I don’t think thats a good solution because what if some other ships just move faster and it also looks wrong.
The best solution could be that the ship cannot collide with its own bullets - but how can you do that? In my game there a more ships (I think up to 32) and each ship can spawn it’s own bullets. I read about collision groups, but is this applicable in my case? Because I don’t have only 3 of them, but each ship needs to have his own collision group them, right? But of course ships must collide with each other and bullets from every ship (except the one the spawned the bullet) must collide.
I also thought about spawning them with a GhostControl and some frames later giving them a RigidBodyControl, but GhostControl does not have a linear velocity.

Any advice?

I would not make projectiles actual physics objects at all, just do ray tests to see if they hit something. And move the ray test location at ship speed + projectile speed to avoid the collision issue.