The System of Long Range Firing built into the M4's ACOG optics as detailed by the link no longer works in DayZ standalone. Because the ACOG optics in standalone only magnify 2.34x rather than 4x, the overlay built for 4x zoom does not allow the system to work.
https://www.youtube.com/watch?v=Ic_0kZxLz_4
SIMPLE DESIGN FLAW.
CONSTANT ISSUE.
Try it yourself with Arma 2. Hit some long-range targets with the M4 ACOG and notice that your shots land using that system.
Reproduce and try it in DayZ Standalone. You will miss.
I agree, we need to block the fov when 1st person and aiming to make scope effective.
Plus, the zoom system based on scope is wrong. If you look at the ACOG for instance, inside and outside scope have the same zoom level and only the player's FOV changes.
http://i1.ytimg.com/vi/mNLTNTLp8yQ/maxresdefault.jpg
Outside scope should remain player fov and inside scope should be magnified fov. Like this :
http://www.firearmsworld.net/sight/trijcon/retvd.jpg
Or maybe that's not even possible on the current engine... maybe Infusion? :)