Have some modern .22 LR cartridge boxes. What does marks on cartridge box means? Is it possible to know when these cartridges were made? Need any information for my forensic investigation.
The first four characters are similar to the normal date code of RWS cartridges after 1945:
Subtract 40 from the first two digits to get the day of the month. For example: 56 is 16th day.
In the case of .22 LR, the next letter identifies the month, starting with A through I for January through September, W for October, X for November and Y for December. (This deviates from the normal RWS month code K through V for January through December.)
The last letter (A through Z, not using J) repeats every 25 years. K could be 1940, 1965, 1990 or 2015.
One would have to know which of the boxes you show have the EU explosives symbol, which has been introduced rather recently. Assuming all boxes are from approximately the same time frame,
K = 2015, M = 2017, N = 2018
The last digit shows shift (1, 2, 3) and production line (4, 5 or 6):
3 = line 4, shift 3
4 = line 5, shift 1
7 = line 6, shift 1
8 = line 6, shift 2
9 = line 6, shift 3
The above information is based on a Dynamit Nobel document dated 1980. Keep in mind that the ammunition shown is from a much later date. In particular the production line/shift information could have changed. The .22 LR is identified as R50 in the document, which strictly speaking is only one variant (others are R25, R100) of rimfire ammunition. In any case the year of production code is the same for all types.
Edit: fixed years for K, M, N
Edit2: Sorry for missing the obvious: mention of RUAG (takeover in 2002) on the boxes confirms the date of manufacture mentioned above.
Millions thanks. Your complete answer is so important for me.