When in a tank, every tank around you plays the same sound for firing their main gun as yours does. They may each have unique track and engine sounds, but everyone's gun mimics yours.
The Ostwind fires one round at a time, yet if you watch someone else fire one it fires three bullets in sequence. When a Wirblewind's turret is destroyed, the gunner can hold down the trigger and everyone else will see (non-lethal) tracers as if the turret is functional. If you have tracers disabled while using a Wirblewind you can't see your tracers, but the enemy can.
One of the acks in towns only fires one round at per burst (the others fire four). I believe it's in the NW corner.
These are all old bugs that I believe I've reported before, but they still tweak me.