But nothing happened

For two obvious reasons:
-I was not wearing my headset nor my track hat
-The game doesnt support trackir

I noticed on Red Orchestra, that the weapon is not sticked to the view, when you look around, it goes a bit farther on the side than where you are looking at. Where i'm going is that the game is also Unreal Engine based, so i they achieved to make the weapon not fully sticked, why dont they make it freelook? and why don't other game on the same engine couldnt ?
(despite having to make 2sided weapon models and stuff)