The ranging indicators on the RPG-42 scope are incorrect and make it very difficult to accurately hit targets.
See this video: https://www.youtube.com/watch?v=TEBpIVB8F8s
It appears that the launcher is zeroed at 200m, so the 200m ranging works. Every other ranging over or under shoots the target, to a ridiculous degree at the 500m range. For reference, it appears that the 3 aimpoint actually corresponds to about 500m range.