Good answers. One problem though. 20mm does not equal a grenade. If it did and I put one in your plains tail or wing you would go down. It takes several 20mms to kill a plane. It takes a couple hitting several feet away from a target to kill it. Thats not right but we have been down this path before, so I will drop it.
FYI, there is a ground effect on 20mms. Next time you try to vulch try this. Fire a few rounds close to theplane on the ground. Do not hit the plane. Just a very short burst close to it. Next, try hiting the plane with the same number of rounds and see the difference for yourself.
In anycase, I don't mind a few easy kills by not having to even hit my target
