Hi cuirc,
Your wish is very well understandable. Yes. Thats what quite a lot of K31-owners think. (included me
) Not all are courageous enough to point that out publicly. The are since a long time many different K31-Sniper-resp. Targetrifle-conversions known. Some examples in the pics below.
The technical aspects depend particularly on the time or period to which your K31 should match then. For example 1950, 1970, 1990, perhaps ?
To the scopes yourself: As far as I know - there are just 3 old scope-types which have actually been installed here in the Swiss Army - including test-examples and serial-rifles. The K31/42, K31/43 and the K31/55 resp. Zfk 55. The most comfortable of them is in general opinion the 3,5x of the Zfk55. But that is probably not easy to find nowadays. Unfortunately, I don't have a source for that now.. .
Some 100 K31 around 1949 with probably 4x-Kahles-Scopes, were first sent to Nicaragua. But they reached then Israel as far as we know. Pic down. I remember there was an article to that subject, some years ago. A journalist could find one of the gunsmiths from then by Hämmerli. This said that he is not really sure with that Kahles-Scopes.. .
The more comfortable 6x scopes only appeared - generally - in significant numbers in the 1970s. Maybe you can find an older Schmidtund-Bender or Pecar with 4x-power.
My Zfk 84 (f for fictive)-Conversion with his 10x-Zf is too modern in that case.. .
What is then a suitable scope for you, cuirc ?
Which reticle and which magnification, f.e. ?
Just my 2 cents