I don't know of one, Randy, but there's a few things you can do that will help your gunnery.
First, hitting a moving plane with AA is like a quarterback tossing a long bomb to a receiver racing down the sidelines. There has to be enough lead so the ball and receiver meet, and enough elevation so the ball drop due to gravity will still allow the ball to be within the receiver's grasp.
One thing that helped me was to abandon the twin-guns and get myself into a single 5in gun on one of the escorts. If the threat is coming from the front, I get in the fwd guns of one of the back two escort ships (right side two ships in hangar). If threat is coming from behind, I get in the back gun of one of the front two escorts (left two escort ships in hangar). The reason I did that was because it's easier to track them and still have a good shot when they are above their target ships and you don't suddenly find yourself limited in gun motion when they are most susceptible to disintegration. It also helps you determine where your shells are going when your fire rate is reduced. Yes, it's less effective than a twin 5in, but better for learning lead.
Then it's a matter of leading the aircraft in such a way that your shell and the planes merge. Obviously that's going to differ based on plane type/speed and altitude. For bombers hitting a CV, most don't climb that high because higher alt means more time to turn the CV, thus spoiling the bomb drop. So I'd start with planes 5 to 8K and find a good distance where your lead is effective. You'll know the lead is pretty good when you see the black puff of your exploding shell going off close to the formation. Then keep a kind of mental tab of what lead you need at a fixed distance... say 5K your lead is about 3/4" of screen with no zoom. Once you find a spot where you're connecting, then adjust from there. You'll reduce the lead gradually as the plane gets closer and expand it again as the plane is outbound. That's something you just have to practice to get a feel for. Then, once you have it pretty solid for, say, B-17s, along will come a set of TUs and you'll have to learn it all over again because they are so much faster.
If you aren't having much luck, do what the 88 gunners sometimes do. Set up a shot well in front of them and start blasting away. One of them will hit home and you'll have an idea where your lead ought to be for that plane/speed/alt. Adjust from there. If you still can't find a feel for it, then switch to HE rounds when no enemies are inbound and aim directly AT a friendly 5 or 6 K away. Watch the arc of the shell and how far below the friendly it passes. That should give you an idea of how much "drop" your AA shell will have (at that appx. range) and will help you better figure a lead for enemy planes. Again, you'll have to adjust from there for different distances/speeds, etc.
One more thing. When bombers are inbound and seen on the dar circle, I don't wait to see them before firing. I get the gun up nice and high, figuring it's going to drop 2in or more at 12K distance and start blasting in that direction. You might not hit them, but then again you might. Damage is cumulative so if you can start pieces falling off the plane from way out, better chance you can destroy them in close.
Hope that gives you a start. Lots of better gunners than I am, hope they chime in here.
