I have had an email from a person researching Warsaw Pact Arms and Ammunition. He said:
[color=#0000FF]I can reveal the secret behind those curious Romanian manufacturer codes 321, 322, 323, 324 and 325: Those are all UM Sadu. Please note that the actual code was “32” and that the last digit indicates the year of production. The end numbers 1-5 are consecutively repeated in a 5-year sequence.
Examples: 321 = 1991 or 1996, 322 = 1992 or 1997,
323 = 1993 or 1998, 324 = 1994 or 1999, 325 = 1995
There are more Romanian code numbers (on large calibre cases or other ammunition parts) that follow the same scheme (some repeat the numbers 0-9 instead of 1-5).
This code system was explained to me personally by a representative of UM Sadu during the French Eurosatory arms show in 2008.[/color]
He also lists “543” as a headstamp for 7.62x39. Has anyone actually seen this?
[color=#0000FF]543 KMZ Santekhpribor, Kazan, Republik of Tartastan
Was only in operation between 1942 and 1947 and produced 7.62x39 and 7.62x54R ctgs.[/color]