Im sorry copy the _i file to a _r file.
If you go into the gamecore\guns\scifi\tavor and copy the gun_i texture to an gun_r texture then put it in a level and use it, you will see that the scope image is a reflection until zoomed.
Pretty cool if you can get a good map.
_d - diffused
_d2 - Oversaturated diffused
_n - normal
_s - Specular
_i - irridescence (seems two be to white spots for specular shine on the scope glass. it put the gun_cube.dds map on the glass.)
_r - reflection (Same as _i texture).
Might only work with a weapon shader though. will have to play with it.
This was posted in a thread a while back.
Nothing but coffee in my veins