Yea we hear lots of things that supposed to have happened during the war. Tell me how are they going to know if your out of ammo to hunt you down? Your going to have to let me pull my guns on you, but I don't think your going to fly in front of me to find out.
It would be a problem if your in a circle jerk with an enemy and your airframe is able to turn with him, but his airframe can accellerate better than yours. So you won't be able to exit the fight. Example the Spit vs any German airframe.
As for the P-47...well you won't be circle jerking in it and if your pulling the trigger your behind them, usually at a great speed and the one thing the Jug can do is out dive any enemy aircraft, then I see no problem.
Flying the P-47 to it's weaknesses will equal shot down whether you have ammo or not.