I have the same thing. The framerate hit is worse with tracers on, yes, but still exists with tracers off.
One culprit which nobody has suggested is that when you fire guns, it illuminates half of your airplane...ie firing guns turns on lighting effects.
So even though you can't see it from the cockpit, perhaps betaAH2 is still (uselessly, and im guessing inefficiently) calculating these additional lighting effects.
yes/no?
