Having played a lot I spend a lot of time ranging in weapons that I have been using so I can keep a chart up on my second monitor to easily place my shots at any distance. Full list of weapons and chosen options is below.

*1000m is the max I did for some snipers, in actual gameplay you will never shoot beyond 600m most of the time as the enemies are not in sight, though you can cheese this a bit to get to 1000m max nowadays, before you could do more in co-op. Standard rifles I ranged to lesser degrees as often the scopes just run out of dots to work with.

Do know that in game the arc of the projectiles is not an arc, instead it goes flat and than hits a certain point at which it angles down and then goes flat from there until it hits the next point. For this reason I always recommend going for body shots, only go for headshots if you are within 5m of the mark on the scope.

If you wish to range yourself go the small village in the mountain, it has a nice metal plate on one of the outer buildings which sparks and shows bullet holes easily, you will go up the mountain a little so it is not 100%, but for the purpose of this game it is close enough.

Each image lists the used equipment, some guns show up twice as I run them in a different configuration.