shift + space
shift + L 调高标尺
shift + K 查看风向箭头
Press shift + space to deploy bipod.
Press shift + L to switch the crosshair illumination for russian PSO sniper scopes.
Press arrow up and arrow down? to adjust russian PSO sniper scope zeroing (SVD and VSS).
Press page up and page down to adjust russian PSO scope zeroing for no sniper/marksman rifles (ex AK74 PSO)
Also remember to hold your breath.
Now try snipping with M109 and have fun with sniper gun...
...right sniper rifle... :)