I also played around in a BF-109f setting the machine guns to 500 and the cannons to 300. Being a turn fighter, I was thinking shooting at < 600 with the machine guns in some instances gets an opponent to turn (or burn E letting me get closer). They certainly are not going to down most planes. When I get in close I'll use the cannon.
Setting your convergence to a certain point makes them most effective at that point. So, essentially, you're making them most effective at a distance where you aren't expecting kills, but just to make your opponent turn? That means when you get in close for your kill, you're using a convergence that will handicap you...
Setting your convergence at a closer distance, 300yds, say, makes them most effective at that closer, more likely to kill distance. It
does not however, make them any less effective for making your opponent turn when he's at 500-600 yds.
So, setting them at say 300yds gives you the best of
both worlds, where setting them at 500 gives you the best of
neither...
Also, keep in mind that if you have them set for a given distance, say 300yds again, the spread beyond 300 doesn't really get terrible until beyond
double your convergence range. If your guns are mounted in the wings, 12 feet apart say, then your spread is only 12 feet at 600yds. Plenty good for making folks turn.
And if you open up at 400 or so for bombers, you're guns will continue to get
more effective as you close on your target. Setting your guns at 500 makes them get
less effective as you close...
