Last step I would try before verifying the integrity of the steam files - go to the game's directory, and cut the entire Maps folder, Maps_U folder, and Models folder into a backup location. Launch the game to a vanilla SP map and see if the guns work.
If it still looks screwy with the mods removed, verify the integrity of the game files.
If it does work as it should without the mods, you will know that the issue is residing withing those folders. I would suggest sifting through the Maps and Maps_U folders on your own to see any texture that resembles a muzzle flash, and move it into a backup folder outside the game directory.
Hidden and Dangerous 2 keeps all of its vanilla files within .dta files, anything in MAPS, MAPS_C, MAPS_U, MODELS, SCRIPTS, SOUNDS, or MISSIONS folders overwrite the game's files. You should therefore be able to verify the .dta files through steam without worry, but if you are concerned about the mods you can copy these folders to a backup location as well. In any event, if issues continue it may not be a bad idea to re-download mods to make sure they're not causing the problem. I also personally use jsgme to organize any mods I've installed and to be able to remove them easily if things break.
Last edit: 1 week 4 days ago by jacobston.
The following user(s) said Thank You: snowman, Jeza