When you fire HE you don't see any tracers or the actual round, neither do you see an explosion or any other mark of where the round hit. When you change to AP you see the tracer and the round makes a big A** explosion if it hits a building (HE and AP switched?).
MG tracers (atleast turret MG) are not visable when HE has been fired, not until you fire an AP will you see MG tracers again. The MG tracers goes away while the cannon is reloading.
