Can't Outrun A Bullet Achievement

Note: If playing in co-op, this does not unlock for both players, so create a save beforehand.
 
You first need to equip your best scope. If you’ve been interacting with all the workbenches in the game, you should possess the 12x ‘M84’ scope for the SREM-1 and the 16x ‘A2 Optical’ scope for the M.1903; either one should be fine. Next, if you have it, select Match Grade ammo as it is good for distance targets. Finally, edit your rifle so it is stable as possible; the ‘Control’ stat. The greater it is, the less the rifle will wobble when you’re aiming, so use a combination of the other categories to raise it as much as possible.
 
When you are satisfied with your loadout, start the mission on any difficulty, but ‘Civilian’ is recommended since there’s no bullet drop or wind (and to get maximum magnification from your scope). When the mission starts, equip your binoculars and tag Möller as he exits the house. Here he will only be approximately 240 meters away.
 
Allow him to enter his vehicle and drive off. After about 40 seconds, his vehicle will pass behind a structure on the road at around 450 meters. At this point, create a save in case you miss the shot. When he emerges from behind the structure, press to aim your rifle and wait until he is at least at 600 meters. Press to empty your lungs and line up your shot. The moment you see the reticule turn red, press to take the shot. If successful, you will see a kill cam. If not, shoot again or reload your save so no one is alerted.
 
If you manage to land a headshot and you haven’t unlocked it already, you will also unlock Brains of the Operation (15G).
 
Thanks to Maka91Productions for the video: