Shooting an HE round that explodes under a plane is not main gunning them. To "main gun" them, you need to hit the plane with the round itself.
I didn't use the plane's icon range for this shot. I ranged my gun by blowing up the fuel tanks that I knew were close to the runway. It's hard to see the plane/icon but it flies in to land from the right. Roughly 1.6K, then I used Kentucky windage to calculate lead.https://www.youtube.com/watch?v=KUeDy9IUczY&list=UUGJG5MO8EzB5HA4u6Q4QXow (Image removed from quote.)
Congratulations, you've managed to find a way to kill those heinous pilots that have the audacity to fly a plane in Aces High without actually flying a plane yourself. Maybe we could reduce the icon range that aircraft see the tanks so you are harder to find without reducing the GV's ability to see them......oh, wait.............
Then we should just tell these idiots who get main gunned to stop strafing tanks at low angles of attack like imbeciles.