I believe the following was along the same lines as for which I was searching regarding the Suhl proof facility & the Russian occupiers:


>>I'm not sure on the Italian proof facilities, but I'm highly confident that the German proof facilities were closed in the Summer of 1945 and reopened in September or October of 1945. I've read accounts that the Russian occupants under Major General Ivan Sazonovicha Kolesnichenko, Chief of the Soviet military administration in Thuringia, withheld black powder to prevent sabotage or an uprising. Either before the end of WWII or after October 1945, only black powder was available.
Right off, I can't recall seeing a German sporting weapon proofed in early 1945, but it is possible.<<


https://www.doublegunshop.com/forums/ubbthreads.php?ubb=showflat&Number=261764

Serbus,

Raimey
rse