Here’s a copyright-free Counter-Strike sound pack.
I’m using this in my open source github project, CS-Radio. CS-Radio is a raspberry pi powered device which connects to two FRS radios (walkie-talkies) and plays sound files over the air. It’s for airsoft games. Because I wanted to distribute the files, I needed something copyright free, so I created my own sound files. It’s not all the sounds in the game, just the important dialog sounds for the bomb diffuse game mode. To create the sounds, I used audacity and sfxer.