Changed Scopes

[Mortblanc]

If you click this link and scroll down to the third picture you will see German soldiers using this system to adjust the ZF41 scope on a Mauser rifle. They are using a machine gun tripod as a cradle for the rifle.

https://www.americanrifleman.org/article...out-rifle/

In this instance they are using the iron sights of the rifle to collate with the scope cross hairs at a known distance. The ZF scope mount was made so the iron sights could be used with the scope in place.