I remember playing AW3 which had server side hit detection, that was hard. You had to not only compute lead, You also had to compute a variable amount of unknown lag. At least they used bubbles. I had a fight with a pony where I empty my corsair's 50's into it and didn't score a single hit even with the client showing hits. The only sure shots in that game where ones with the enemy wings level flying straight. I have always favored .50's in this game as it allows for more firing time which allows far more spraying the target area and higher hit chance than cannons. I like to compute a firing solution and then when I fire my first burst, I see if its over or under and then adjust the plane in that direction with the guns still firing. I also limit the spraying to only a second or two. You can also do this and just pump the trigger to save ammo but most of time I tend to not think about that when I have an enemy in my sights.