Shooting a 30mm is hard no matter how long you've been doing it simple as, I wouldn't go getting all I'm ready to hang myself over it
Use the .target command and you'll see how difficult it is to get a tight grouping with a 30mm
Fire in ones tap the trigger.
Fire the 30mm seperate from the 13mms.
If your flying behind a target and miss readjust for the slightly for the next shot usually 400 and under.
The best way to kill with a 30mm is with a huge target, if its slow so much the better, anticapate their turn ease of the throttle and pull for a full profile shot ie fly to were they are going to be rather than track them and let them fly thru your sight and pop them on the way past.
Learn to shoot with the 13mms they are more accurate than the 30mm and can bring down a running plane on there own or get it to turn anything 600 or over is 13mm turf.
Scale your rudder so the first 3 or 4 sliders are in a gentle progressive slope for aiming.
The best practice for getting your aim right is the DA furball lake there are plenty of erm drones flying around there lol.