where do i press the f5/f6?? lobby?character screen? or the one that allow me to choose channels?
it doesn't matter
as long as u press it even u alt+tab to desktop and press will effect on your game.
But if u press it twice then it will be same as u didnt press at all.
And I notice that there is an interval of time the recoil reset back.
So just see whether you got recoil or not. If got recoil then press F6 again.