[Stratodog]

I'm not sure if this helps, I haven't been able to see the video yet (don't have a player for .avi files); when I did some aircraft modding in a different combat flight sim I altered the rate of fire of each installed gun by just a tiny bit. (Real machine guns don't fire at exactly the same rate) It produced a slightly more random and stream like look to the tracer fire. Another idea would be to start each gun at a different part of the belting. (One where the first round is a tracer, another where the 3rd round is a tracer etc.)

I don't know if these things are possible with IL2 but maybe it would help. BTW I think the belting is probably right (1 tracer every 5 rounds).