Tbh I don't think there is any movement sway at all. It's just the scope crosshairs moving around but not the actual location of what you are aiming at.
Yep thats what I am talking about. Even this little bit doesn't effect your aim. If you aim at the head while walking you can still make a 100% head shot. While in mw2 the bullet would be affected to impact in a different position even aimed on head. Its quite nice to see in sniper montages of mw2 and ironsight. In ironsight most sniper walking with the sniper while in mw2 they stand for a fraction of a second at the same position.
In cod mw2 it was countered by the fact that you had to release your fingers for a fraction of a second from the movement keys. Otherwise your shot wouln't be precisely enough to match the crosshair middle point. In Ironsight however you can walk with your sniper without loosing any precision. That is what I think needs to be amend.