I finished the game the other day, and when I listened to the 682 battle, I noticed that the distant apache gunshots didn't match the ones when the one apache fired at you as you escaped. So naturally, this tickled my OCD the WRONG WAYYYYAAH. I immediately set out to find that "light, chainy" heavy machinegun sound effect. I downloaded it and ripped it out. The sounds now match and my OCD has calmed down, and I felt like contributing it here, since the collaboration section description said you could contribute textures and sounds you had.

https://www.dropbox.com/s/db6ndpwsvbz7yol/gunshot2.ogg

Since the chopper has a high rate of fire, it sound faster than it should, but at least it sounds more like this

http://www.youtube.com/watch?v=3m79NA44jYk

EDIT: Uploaded a different one, same link.

Well, Apache's gun is actually an M230, but this "m249" sound effect great for it.

More sounds: http://www.youtube.com/watch?v=Yii32Kerr1U

Maybe Apache should sound more like a Browning .30?
http://www.youtube.com/watch?v=qGlubA_9RbY

Pew pew pew.