its not mine, but this is Grizz's post on the matter.
http://bbs.hitechcreations.com/smf/index.php/topic,280043.0.htmlto b frank if you are used to using bullets to tell where your bullets are going (like a lot of US planes that have lots of ammo can do) then you are going to find this a hard cannon to master - however, if you master you revi16 and get a good idea of how the 30mm behaves, then you will perform deflections in 3 - 5 30mm round per shot which is my average. No tracers to give you a clue for the next shot because by then you are already performing the next set of ACMs to make another shot. In essence - you have to spend a lot of time practicing.
the only real hint I can give is this - you don't actually want to saddle an opponent with a 30mm - you want to create the high angle deflection shot. Use your 12mms for saddle shots (takes a bit more time but they work) and when they break, that is when you line up for the 30mm burst. I have had terrible luck with low deflection shots with the 30mm and while I will take the shot if I am low target, low fuel (gonna go rearm anyway) - its really a game of patience and timing - and that is part of its reward. When you see a K4 shooting at you while chasing you down from your 6, and you see those grapefruit sized bullets wizz by, you know that they are desperate and will egress bingo ammo soon. Just make sure you keep your profile small!!