An internet search showed that some PPSH41 SMGs were converted to 9mm by the Germans during WW2. They were known to not only place captured weapons into service, they also came up with their own designations for these weapons. In some cases, such as the BHP after the FN plant fell to German occupation, BHP's were still manufactured, with the magazine safety omitted and German military markings added, then issued for use. These nazi BHPs are a desirable collector piece. Going back to the PPSH, I have heard tales of PPSH SMGs captured in afg that were also chambered for 9mm but retained original Russian markings and date codes, although I never saw one (at least to my knowledge- I did find several ppsh in enemy caches, but I never inspected one closely enough to determine if it had been converted, since number 1, at the time I didn't know that was actually a thing, and number 2, I had no desire to fire or otherwise use the weapon which to the best of my knowledge was chambered in 7.62x25 p, due to the fact that the ammunition was not really available, and I didn't intend to utilize such a weapon anyway. The several that I came in contact with were destroyed or rendered unfireable and hung on the walls of our briefing/MWR room on the base as decorations, along with samples of other unusual weapons we captured.