For the purposes of this thread, I think attacks made against buildings should be left out for two reasons. First, when a bullet hits a building, all the kinetic damage counts. That is to say hitting a building at 1000yds or at 100yds doesn't matter against a building.
http://trainers.hitechcreations.com/guns/guns.htm. This actually evens the playing field of cannons v. machine guns. Second, buildings don't have parts, so the importance of convergence is diminished. Knicking the sides of a building does the same damage as hitting the building in the middle at perfect convergence. I don't think anyone here is arguing that .50 damage should be upped as against buildings.
If I'm wrong about the damage model against buildings then the statement is withdrawn. Otherwise, the building damage model is a completely different and simpler animal.
So about the spit16 v. p47 comparison. The 20mm Hispano does 4.03 damage. The .50 does 1.17. A spit16 does 10.4 damage while a p47 does 9.36.
That means a p47 does 90% of the damage a spit16 does when both pilots tap the trigger. It sure doesn't feel like it.