Lathrobe,
Offline fill all six drone slots with I16. Using only single taps, attack them from every conceivable angle and them some. Do this for 15 minutes every day prior to logging into the MA. The MK108's timing is completely different than the other auto cannon you shoot with. The I16 is so tiny you will be forced into a timing that will place rounds dead center of the normal rides in the MA. 200 and inside your aim point is about 6Mil low of center. 400 its about 12Mil low. lead is the bugger.
Like I said earlier, 350 will give you the flattest trajectory to 400 in relationship to the LoS that Hitech has programmatically setup in the game.
You can test this offline with the target. Remember that the red horizontal center line is the center line of your aircraft.
Set the K4 to auto level at 312 IA. This will level the cannon barrel to zero. Then shoot at 100, 150, 200, 250, 300, 350, 400 with the MK108 only. Make notes of the relationship between the center of your gunsight and the IP blob center. When you are finished, compare the trajectory of the rounds to the gunsight center as a trajectory graph. You will find before reaching 350, the trajectory passes high to drop into 350. Then almost the same amount low hitting 400.
Just remember this trajectory is not passing high of your aircraft. It's just passing high of your LoS which is angled down to account for having a cannon mounted into your engine. After all of these years, I've come to accept the less than 1 degree tilt Hitech allows through the engine block with the german auto cannons with his convergence program.
In real life they were bolted inline to the engine to bisect the prop plane at 90 degrees through a hollow tube set parallel with the engine crankshaft. Can't have a tiny grenade setting itself off in the blast tube. In flight at combat speeds in our game the dispersion and variable AoA at different alt and speeds blurs the small amount of convergence tilt Hitech allows.
I'm thinking of revisiting Yak gun mountings in the Kilmov engine. The mounting is taken directly form the Hispano-Suiza 12Y, Hispano-Suiza 404 20mm mounting solution. The cannon is bolted down to the top of the block between the cylinders with locking mounts. Not like the Dalmer-Benz, inserted from behind through a pre set hollow tube into the engine. From looking at a Hiss12Y from the front with a cannon mounted to it. There is enough clearance room in the reduction gear pass through to adjust almost a 1/2 degree across 360 because the reduction gear housing is mounted to the front of the block independent of the HS-404 mounting solution. Looks a lot like the arrangement in the P39.
I found a Russian reference to the Yak's 20mm being set to 200 in relationship to a sighting mark on the back of the prop that the pilot was supposed to eyeball his PBP\PBK reticle center against. I can concede the P39, Yak, D.520 had adjustable harmonization for an IP point now after what I have found. The reality of the tolerances involved makes a 200yd IP probably what was set and locked for the combat life of the aircraft's engine or the gun barrel. I suppose the NS-37 it was a miracle just to get that monster mounted to that tiny engine.
