Get any weapons with any attachemnt, make a game in editor keep settings on normal so that you can scroll wheel to get range. Use RCO (its easier to spot error, becasue the RCO scope Zero is sort of messed up already) Aim and shoot at a target 300 meters away usign the red dot of the sniper scope, repeat with 400, and 500. All shots will be hits. Aiming at a target above that is difficult because the other ranges are now off by ~ 80- 100m ie an object 700 meters away will need to be fires at using the 600 meter marker.