Thank you all for your posts.
I am triyng to figure out which scale is the major one and wich the sub-ticks one on my rawson.
Is the "major" the one reading from 3 to 10 on the right of the post or the other one on the left? (pls cfr Adrians pic above).
Could it be that someone has a clue if user manuals were available for these sights and where to find them nowadays?
Anyway I am grouping much better at 300mt with my rawson.