What you are showing in your film is a not at all related to the original post.
Sure, I grouped together the 88mm bug along with the M4 shooting up a base he could not see into the same post I linked to but they are two unrelated issues.
The reason I grouped both in the same post is that it's the same person performing the miraculous feat.
Here are 3 pictures I took from a film of the exact same moment from 3 different views.
Picture 1 is facing the field that is shelling mine and blowing up ack as the rounds pass way over the base.
You have to look very hard to see the two tracers.....one just left of center of the blue sky and another below it near the horizon.
Picture 2 is facing where the rounds are eventually exploding after passing high over the base meaning the enemy base doing the shelling is firing over your shoulder from behind you.
It's just as difficult to see the tracer dots but you can make out 3 tracer dots and the explosion of the puffy ack below them but just above the horizon.
This shows them after they have passed over the field and his distance setting seems to be about the maximum.
Picture 3 is taken from a player's perspective in an airplane and you can clearly see the tracer dots traveling over the base.
This is not the same as somebody accurately shelling the base from a M4 or other GV.
You can clearly see a hill between the fields in the picture facing the field doing the firing.
I switched sides to knight, upped into the 88mm and was able to duplicate this by setting the distance to 12k (maximum) and firing way over the base I was at when I took the pics.