Aaahh! you want some separation, laterally, at 'convergence' range. Ok, well that's up to you. Most of us are trying to get maximum, or 'point', concentration at convergence for maximum damage. However on fuselage guns we sometimes set long range like 600m-800m for longer range hitting (which is more achievable with fuselage guns and useful for ground attack) and still good for shorter range air to air with a lower aim. You can't separate elevation from separation in IL-2 convergence setting.

I got the numbers from Kodiak's chart as he put that up as an example and a reference. If they are accurate for that aircraft, and they look like it, the numbers would only apply in that instance but the example is generally relevant to all.

I don't think there are ballsitics tables for IL-2 but there are masses of ballistics data out there on the web. I made a spreadsheet of them from a few good sources.