Well there is somewhere a tutorial how to add weapon to game. But in your case first You need to find 3d model of weapon you won't to have. Also you must be sure that this model is compatible with Stalker engine. Off course this model must have animations to. Try to search in other modes for stalker since porting weapon from one mod to another will be much easier then creating new one from scrap.
Try Arsenal Overhaul. It's the only mod that I remember who include attacheble colimator scopes. I was able to port one AK type with cobra colimator to TAZ. Unfortunately attaching option that work in AO not work in TAZ. It would demand a lot of TAZ rebuilding and make TAZ to have like 6-8 gb. But porting weapon with fixed colimator from AO to TAZ should be possible for You.
Kain85
joined
This member has provided no bio about themself...