When you fire the last pair of 40mm rounds from the Hurricane IID, no sound comes out. This is very noticeable because the 40mm cannon is often fired semi-automatically. When firing automatically the gunshot sound effects don't seem to be in synch with either the ammo counter or the tracer graphics, and furthermore the last gunshot sound stops abruptly. In fact it sounds as if the gunshot sound cuts off the moment you release the trigger.
A similar bug was mentioned a few threads down about the Yak-9T - the last 37mm round doesn't make a sound either. Perhaps this is the case for all aircraft weapons; it's very noticeable in the IID and 9T because their guns are often fired in very short bursts.
