I can knock multiple Stukas down with a single ammo load.
Set convergence to the right distance, use small variations (1 to 2 m) in guns if you need a spread.
Put tracers on your outside guns (1 and
Put Armour piercing. incendiary in the middle guns. (don't forget to load De Wilde ammo!)
Get up to your convergance distance. Learn where this is, what it feels like to be there and get there every time.
let rip. ratta-tat-tat!
Boomie boom!
As soon as an AI stuka drops out of formation, they generally crash. It's different from Il2, the way the "killed" aircraft behave. You often don't even need to knock em completely out, just stop them from being able to effectively fly home.