I remember reading about this problem awhile back, its also probably what makes people wonder if ammo is modeled correctly, if you have guns 4 & 5 with AP, and the rest with De Wilde, but only 4 & 5 are firing, figures why some folks are not seeing planes burst into flames. Its probably why some weeks I do well with kills, then they drop until I start tweaking ammo belts again.
Sometimes I look at this sim and think wow, other times, its like
Backward convergences, Guns not firing, blah blah blah.
Best part is, as much as this community gets under the skin sometimes, if it wasn't for the people here picking the game to shreds, half of these problems would have been left un-noticed.
Maddox Games really need to pull their socks up for BoM.