This is the Nagant Competition revolver match load. I forget when the big matches were held at Phoenix, Arizona, for the 40th World Championships, as I recall, and the Russian shooters brought target revolvers based on the Nagant and this sort of ammunition. A lot of it seemed to be left behind. Also, I think that some was imported some years ago. There seems to be a little more around than could be accounted for by the Russian team selling off the left-overs. I don’t know if it is the same date, either.
See Erlmeier & Brandt, Volume I, Handbuch der Pistolen- und Revolver Patronen, page 91, Cartridge Number 61 - 1P.
Ii is hard to classify this, since so many of the Eastern atheletes were basically professionals paid by the Government. Does that make this commercial ammunition? Tough to say. It is not the standard military revolver load I think, because it seems the bullet showing is lead and flat - a target wadcutter. Some would call that commercial. I couldn’t disagree, one way or the other.