Does anyone know why in this graph the sighting line (visierlinie) is not drawn as a horizontal straight line?

I missed your point on the first read... I actually think it is just for clarity. You could swap the graphs but that would be even more confusing, IMO.

Oh I find the slanting sighting line a bit confusing. I've seen a similar weapons trajectory graph in an Fw190-A8 manual. But there the sighting line is horizontal, as is what happens in reality when the fighter's guns are being calibrated on the ground.

The reference point is barrel elevation (Mündungswaagerechte) ie 0° or horizontal

Ah! I see . But only the MK108's barrel is horizontal.

The main culprit missing is effective bore. There's no possible way the developers could have this data individually modeled, let alone have acquired the data for every type. It's pretty easy to learn gunnery when every type has the same airspeed to AoA relationships.

Here's two harmonization charts both for P-47's, same aircraft but worlds apart in how the guns are physically set up. Seriously doubt you'll match the same specs for either in game. The FP, FSL, and Mil Rad angles for this specific aircraft won't match generic game data........

You may have accurate ballistics and ballistics modeling, but that's only half the story.

The two images are quite fascinating .

It's disappointing that such game data as a certain gun's muzzle velocity in IL2 have never been made public.

nodak, your charts look like "pattern harmonization" (you get a stream of bullets covering an area ahead of you at different distances) and "point harmonisation" (all bullets cross their paths ata defined point) which were the two basic choices for fighters back then

the game models the latter one, maybe not perfectly, but it's the "standard modelling" for IL-2