S/42 1940 dated with X marking

[photo-war]

Originally Posted by Edward Tinker

But I think, just like export and import stampings, some slip through

Not every RC gun has X - there are many guns with no such markings. But X could be observed on almost every type of firearms that came through the former Soviets arsenals (mostly based in Ukraine: Shepetovka, Balakleya etc.) - MG34/42, MP44, MP38/40 etc.

To me this X could stand for "removed from inventory" - when the gun was sold/imported and its number was removed from arsenal's lists of gun that were on storage there.