How do I give a sniper rifle manual zoom? So while zoomed in, you can`t move and to zoom in you press the "W" key?

Help yourself! You know that weapon zoom from the game. So where did you use it? A turret from stock game? Or a mod (BFx)?
Next go to the stock assets/released assets and look for reference.

If you have still problems to find it, let us know

I remember using it in a mod, don`t remember which mod though. I know it`s used in things like the tri-pod turret, but I looked around and couldn`t see anything that relates to how it aims