Open the ship's dat file, and see if there isn't an "F" and a "B" designation for the ship, with the gun attached to the other end of the ship, such that when you "break its back", the bow might be sinking a bit faster than the stern initially, and with the gun attached to the stern, it separates from the bow "mount" and floats. You'll see that with the "crew" of some ships, or the spotlights, etc...
