I think the majority of the sounds are the same, I used to use the weapon skins. Anyway, you download GCFScape
http://nemesis.thewavelength.net/index.php?p=26. Once installed, open it up. Go to File->Open and head over to your SteamApps file in Steam. Once there you'll see a bunch of .gcf files. Opening each of these you can extract each sound, skin and model for every game you own on Steam. The file you're looking for is Condition zero deleted scenes sounds.gcf. Open the first couple of files and scroll down to weapons. I'm assuming you know how to extract the files from there and where to extract them to.