all this just does is simple. it takes the player weapon sounds, and it takes the NPC weapon sound's place.
INSTRUCTIONS
so, we throw in the folder inside the RAR to your hl2 custom folder. if it doesn't exist, make it yourself. it's that simple
(incase you didn't even read the title, this is for the overhaul muzzleflash mod. not vanilla half-life. if you want the original mod, go here: Moddb.com )