I've been killed out to 900 a couple times by .50s, I'll have to check and see if I have films. I think it was either Tac or Lazer that killed me in a a Ta-152 (he was in a P-38) - it read 900 something on my end, but it may have been closer on their end.
Also wulfie, if you fire at GVs while you are in FIGHTER mode, that HURTS your hit%, not helps it. I should know, I strafe M3s all the time on base defense (and LVTs lol, I probably wasted 1000 rounds trying to kill a LVT in a Hurricane I).