Blammo,
Sounds for guns such as the 20mm, 30mm, M2, etc will all have multiple ones, I.E.: 20mm_1, 20mm_2, etc. This goes for each gun on that plane itself. If you have say a tempest with 4x 20mm's on it you will have 4 of those files listed. M2's or machine guns start with M2 and then go to M2_2, M2_3, and so on. I make on sound for each gun and find it works. Not 100% sure if you can just toss in one sound or not and it will work, but I just go with my way because it works for me. (not telling you what to do)
As far as explosions, damage, gstrike & hits, you will have multiple ones of those because of the different explosions in the game, such as a plane blowing up or a building blowing up compared to a bomb or flak burst going off. Damage is hits on your plane, which unless your like me and get one ping and die, you will hear multiple hits on your plane and they will all sound different. Add different hit sounds to your GV's folder because it is hitting a hard metal/armor so it will sound different.
One of the best ways to do it is to 'listen' to the sounds in the game and when your working on your pack imagine what is going on and what sound you want to here. That way you will start remembering what sounds come from what shot on your plane, or what explosion your hearing while dive bombing the task group.
If you need any more help let me know.
