There has been a conversation on these boxes which date from 1938 to 1943. It has generally been assumed that the “N” identified the ammunition as a product of RWS Nurnberg (see thread https://forum.cartridgecollectors.org/t/9x19-rws-nurnberg-headstamp-from-1933/29054). This is supported by the cartridges in boxes from 1938 to 1940 having RWS headstamp and the primer supplier as “N.S.” which almost certainly stands for RWS Stadeln which made all the Sinoxid primers (marked with an impressed “O”).
This issue is a bit confused because, beginning in about 1930 or a bit earlier, Geco manufactured all pistol caliber ammunition for RWS including 9mm P08, except for ammunition for the military. The “N” code boxes are in the German Army format but “N” is not a military code and the data is not as complete as required on German Army Labels. As a result, it is possible that the ammunition was considered non-military and was actually made by Geco for RWS who sold the ammunition to the “non-military” customer. The complexity of this was discussed in thread https://forum.cartridgecollectors.org/t/who-invented-and-introduced-the-sinoxid-primer-and-when/29265/30. One argument for Geco manufacture is the fact that during 1940 the RWS cases were replaced P405 (Geco) cases and subsequently by dnh (Geco) cases. P405 and dnh were identified as the case manufacturer on the labels. Beginning in 1940 RWS was making 9mm P08 for the German military and their cases were headstamped P151 and dnf. Since Geco cases were used in the “N” boxes from 1940-1943, it has been argued that this indicates Geco as the manufacturer.
Recently I have been going through my German boxes from th3 1920s through 1945 in an attempt to determine who was making P08 primers and which loaders were using which primers. In the process I ran across the box below in my collection.
Although the label states that the cases were made by “N”. they are in fact Geco headstamped cases.
This could be considered proof that Geco made the cases identified as “N” on the labels, but the box was not sealed and is not full so the possibility that these rounds are not original to the box cannot be ruled out.
This is an interesting discussion with implications for the manufacturer of other ammunition found in non-military standard boxes.
Opinions are welcome.
Note that quite a few of these “N” boxes are pictured on the other threads referenced above.