For a long time I always said that the sounds in arma are..ok just ok and not great but this sound mod I picked up which is very easy to install and adds new sounds on every weapon including DLC and I will tell you what its scary, normally arma sounded too lackluster and dull (too me) but now its making me want to put even more hours into just for the sound!
http://www.armaholic.com/page.php?id=11549
Also this is more of a single player thing just to mess around on but I also been playing on my map with is based off Hellmand Province.
http://www.armaholic.com/page.php?id=14455
Enjoy
I'll have a go at adding them. Sadly though I doubt I'll get it done this side of tonight's action. You Tube vids look........ sound great.
If you need help installing it, its just a matter of:
1: Download it, unzip file to desktop
2:Find your ARMA2 OA folder and copy & paste it into there, folder should be called@JSRS1.4
3:Right click on the game to go into launch options and type -mod=@JSRS1.4
And that should do it, it worked for me!
Can confirm it makes an amazing difference and recommend all try it.