20mm cannon on German AFV. No muzzle flash.



MG-42 firing multiple bursts (7.92mm). No muzzle flash.



Vickers .303 firing multiple bursts. No muzzle flash.



Unless I'm mistaken, that's all of the main rounds used by both sides. 20mm and 7.92mm for the Luftwaffe and .303 for the RAF. So they should not be visible during the daylight, but should at night.