Because there is a minute amount of movement in the idle animations, the "painted on" reticules misalign with the gun's barrel. Because of this, your gun won't quite shoot where you point it.
Suggestion:
The misalignment could be an interesting feature if these two things would be added:
A: The alignment would need to be controllable, for example by holding your breath.
B: You would need a clear indicator to tell if your scope is aligned or not. Scope shadows would be a good method. (separate ticket at: http://feedback.arma3.com/view.php?id=10085 ) {F20077} {F20078}