the proof marks are german and this would imho exclude a rifle deliefered by Springer's Erben in Vienna.

the 22 gramm bullet proof weight is my problem

the bullet weight for the 10,75x52R Gründig would be 22,5 gramm.
if for the Gründig cartridge I find the lack of precision disturbing.

anyway, you have to made a chamber cast, straight or shoulder thats the final question.
if its the Gründig cartridge there is a chance this double was made by Sauer&Sohn.