Here's a little mod I've made which replaces the single shot type of small arm sound with something more akin to an actual fire fight. The three categories of light, medium, heavy are reflected in the intensity of the distant gun battle.

Unzip and place in C:\LnLGames\Command Ops 2\Sounds\InGame\Weapons\

I recommend you use it with the excellent Krause sound mod which can be found here: http://www.matrixgames.com/forums/printable.asp?m=2584880

If you uses this put mine in after K's