How many AT guns used tracer anyway? That's interesting. In 'Panzerjager : tank hunter /
by Averbeck, Bernhard, 1924-' The effect of firing a gun is blinding, such that those at the gun could not see the shot and an observer a distance away with binoculars had to relay corrections to the gunner. The way I read it the spotter noted the dust where the shot hit the ground, I don't recall any mention of tracers for the German AT guns.