I've recently ran into a sound related problem with rapid firing weapons.
When using a weapon with a really high ROF (near realistic Gast and Gatling guns), especially in "cycle" mode (gets noticable when using Chief's weapon linking), some sounds become really quiet at random after firing a burst. While I'm sure I don't overload the object limit (these guns are supposed to be used on 2-4 fighters at the same time, not to mention bullets have high velocity and short life), that sound issue is annoying, since it seems to only depend on ROF and happens even with one fighter using the weapon.