Good gunnery requires a balance of many things some the pilot can control and some he can't.
He can control what guns to shoot, his convergence, the maneuvers he performs to saddle up for a tracking shot or that snapshot opportunity, his timing or when to shoot and his aim or where to shoot.
He can't control the maneuvers the bandit will do, whether the bandit will fight alone or is screaming on his country channel for help, the small but omnipresent netlag and the net itself.

 

Personally most of my guns are set around 300 or so convergence with a few exceptions. It's even more critical to adjust them now and the old 'nose guns to max' doesn't even really work now. With 4x.20 Hispano cannon I set it to 400 and I believe my P47s with 8x.50 have a spread convergence from 300 to 375. I figure even the bullet stream inside or outside the convergence setting will damage something that crosses it. My Typhoon is set to 600 because I use it for strafing ground targets 99% of the time.
When you get in close and hit the target at the sweet range of your guns it doesn't take much for serious damage, unless using a smaller guns like the .303s. Personally I'll take 2x.50 over 4x.303 any day, they have a higher lethality and the ballistics are better.
Setting gun convergence and matching it to your shot is more important than ever, even with nose guns.

Click photo to enlarge

We have the normal convergence issues shown at the top of the picture with it effecting wing guns more than nose guns. However, in the bottom picture you notice nose guns are still effected due to bullet drop.
If the target is closer than your convergence setting you should aim slightly low because the rounds are at the top of their trajectory. If the target is farther than your convergence you should aim slightly higher as the rounds are past convergence and dropping off fast.
The closer you are to the target is the key. Try for that 200-300 range on the icon. That will be a D200 which covers actual range of 100-299. The D400 icon is anything from 300 to 499. Keep that in mind also when using icon for ranging. That was one thing I forgot to mention last Tuesday. I wanted us to line up with D300 between us to look at and study the 'size' of the plane in front of us compared to gun site size. We shouldn't rely on the D icon range to shoot, the info it gives is way to vague to do that and expect accuracy.

Fuzeman