RWS-Geco Relationship prior to WWII


John Moss and I have speculated for some time that pistol ammo marked RWS and Geco from before WWII was all made by a single company. Except for the headstamp code the rounds were identical down to the style of lettering on the headstamp. The boxes were also very similar. It made no sense that two independent factories were making items so similar. An example below.

I asked some questions in the “Cartridge Researcher” the monthly publication of the European Cartridge Research Association, an excellent organization for collectors and researchers. I just received the following answer in CR #540.

[quote]From Jürgen Ahlborn (Germany)
540-3 To Lewis Curtis (USA) 538-8: Relations between RWS and Geco between the wars
In 1927 a contract was made between RWS and Gustav Genschow & Co (Geco). The content of this agreement was as follows: The pistol cartridges and shotshells of both companies would be manufactured in the Durlach plant of Genschow and the rimfire-, revolver-, and Flobert-cartridges, the primers, cases and air gun pellets of both would be manufactured in the RWS plants in Nuremberg and Stadeln. The shotshell cases of RWS were still manufactured in Nuremberg. This contract applied from 1929 onwards. In 1931 RWS became a part of the Dynamit Nobel Co. but nothing changed: RWS was purely a sales organization for RWS products. The production of military ammunition was not a part of the 1927 agreement. The headstamp “RWS-Geco” is not a product of the transitional period; it was used by the RWS plant in Danzig. I am preparing a report about this subsidiary factory of RWS.[/quote]

So now the specimens in my collection make a lot more sense. These are all products of Geco. Great info.

Many thanks to Jürgen Ahlborn and the ECRA.




Lew - fantastic information! Thank you. You are right, we have been discussing that for years and generally in agreement, even though I found few Europeans who agreed with me when brought up with them. The information on the RWS-GECO headstamp is particularly exciting, as I have a couple of rounds so headstamped, and had no knowledge at all of any plant at Danzig. I suppose it was probably completely destroyed in the late-war fire bombing of that city.

Now, if we could find out what the dots in various positions mean on these Geco/RWS headstamps??!! Most of us think its a date code of some sort, but I have found no one who really knows what it is. The same thing goes for the use of “9 mm” as opposed to “9 m/m” by RWS/GECO (on some other calibers as well). Some believe it means nothing, but I am not so sure about that.

John Moss



Affermative. An interesting side note is that the GeCo / RWS plant in Durlach was just a few miles away from Karlsruhe.

The company site has been destroyed to make way for the expanding town. Only the ‘Schrottturm’, a tower built for casting lead shot, survived and is used as location for some local university experiments.

The local history society of the region published a nice little book on the history of the cartridge factory. It includes interesting photos from the legacy of one of the factory supervisors.

The booklet was written by Elga Roellecke in 1994 and it is titled 'Die Munitionsfabrik - Das ‘Zündhütle’ 1897 - 1972.

It was published by ‘Die Verein für die Geschichte von Wolfartsweier e.V.’.

Who Invented and Introduced the Sinoxid Primer and When?

Vlim - is that book still available?

John Moss



Yes. I ordered my copy not too long ago. … &Itemid=54

It is ‘Heft 1’.


In short:

The Durlach plant was erected in 1897 by entrepreneur E. Schreiner. Initially only primers were produced there. The plant is taken over by Gustav Genschow & Co (‘GeCo’) in 1903 and they expand the plant. In 1906 the company is officially called ‘Gustav Genschow & Co.’, a merger of the Berlin branch of GeCo and the ammunition plant in Durlach. Around 1931 the cooperation between GeCo and RWS takes shape.

In 1963 ownershop of the company is tranferred to Dynamit Nobel AG. The plant is finally closed in 1972 and dismantled in the following years.


I guess I am spending too much time on cartridge stuff! I actually had a dream this morning, and woke up with it, about this thread. It related to the question of who made the RWS and GECO pistol cartridges, and how that relates to the military codes.

Since we now assume, and I believe for the most part correctly, that Geco made all of the pistol ammunition marked both GECO and RWS (other than that from the Danzig Plant marked “GECO-RWS”), after their agreement in 1927, the question comes up about why there are separate case-maker codes during the War Years for the two factories, both found on 9 mm Parabellum ammunition. The codes “P151” and “dnf” represent RWS Nürnberg-Stadeln, and the codes “P405” and “dnh” represent RWS A.-G., Werk Durlach (vormals Gustav Genschow).

Two questions come to mind relating to this topic. Firstly, is it safe to assume that because of war needs, that the Nürnberg-Stadeln Plant of RWS was required to open up a 9 mm Parabellum production line of its own? The few “dnf” boxes I have, by the way, show that RWS loaded the ammunition as well as having made the cases.

Secondly, when did the Durlach factory stop being simply “Gustav Genschow & Cie. A-G.” and become “Rheinisch-Westfälische Sprengstoff A.-G. vormals (formerly) Gustav Genschow?” The latter name is shown in the official German list of codes, “Liste der Fertigunskennzeichen für Waffen, Munition und Gerät.”

During the original discussion, we talked only about commercial-style headstamps, and I guess the discrepancy between those and the military codes was in my subconscious, if I have one of “those.” But to dream about a Forum thread is, well…weird! Of course, that probably is just a normal description for me.

John Moss



Werk Stadeln was indeed mainly a primer production facility. It is interesting to note that the company was originally started by the same entrepreneur who started the Durlach company as well. This entrepreneur, called Schreiner also laid the foundations for DWM’s Grötzingen plant. Since Schreiner had preciously little respect for safety and safety laws he was quickly removed from his own enterprises.

Stadeln did produce rifle and pistol rounds during WW1, and continued to make shotgun and 22lr rounds after the war. Other products included flobert rounds, air rifle rounds, hunting rifle rounds, revolver rounds, slaughter rounds, explosive bolts and of course the primers.

Dynamit Nobel GmbH Explosivstoff- und Systemtechnik Troisdorf published a small book on the history of ‘Werk Stadeln’ in 1996.

The German Patronensammervereinigung did a reprint in 1998. I have Henk Visser’s copy here in front of me.


RWS and GeCo were united under an IG (Interessengemeinschaft) on the 1st of January, 1928, but ‘Gustav Genschow & Co.’ did remain a seperate entity with its own name. As did ‘RWS’. They just cooperated and had central administration and sales offices.

So the Durlach factory never stopped being ‘Gustav Genschow & Co’ until 1963 when the company became part of ‘Dynamit Nobel AG’.


Vlim - any idea why an official German publication, the code book (this is a reprint of the original sheets as the were issued, thru “ozz” in the letter codes, not something made up by collectors) would refer to the Durlach plant as “RWS vormals Gustav Genschow”? Could it have something to do with any acquisition of both companies by Dynamit Nobel A.-G. before WWII?

Regarding WWII production, I have only two boxes from “dnf” (RWS Nürnberg-Stadeln) and one shows all components other than powder as made by “dnf” while the other shows the same except for the bullets, which are shown as made by “dnh” (Geco-Durlach). Of course the code “dnf” is complicated by the fact that is was also used by the other RWS plant at Nürnberg, the old Utendörfer factory in the downtown area. So, I guess it is impossible at this point to know which of the two factories at Nürnberg actually produced which components for the 9mm simply by the code “dnf.” for 7.9 x 57 cases, the lot numbers tell the story - 1 thru 50 for the old factory downtown, and 51 and up for the Stadeln factory.

Any ideas on the above from anyone. Lew?

John Moss



I have a copy of the manufacturers lists dating from 1940 (reprinted by Karl Pawlas in 1977), as well as the recent book from Michael Heidler.

The 1940 list shows dnh as

Rheinisch-Westfälische Sprengstoff A.-G., Werk Durlach

With no reference to Gustav Genschow & Co.

Michael Heidler also shows it as RWS without referenc to GeCo.

Gustav Genschow & Co in Durlach is crossed out in the 1940 list (according to Heidler this was done in 1943) and replaced by another company (according to the 8th revision of the code list).

Perhaps the shortage of 3-letter codes inspired a rationalization of the lists?


Vlim - you are absolutely correct. Years ago, from xerox copies of the original lists that one of my friends, a well-known cartridge collector had, I made up a code list that was accurate. To that time, there was nothing even approaching accurate or complete in the USA. I don’t know if I got it off of there, or where. I extended the list considerably when I got the Pawlas reproduction of the lists. I even sent my original list to the German Language group of ECCC for approval of information and spelling and it came back to me with only one or two minor punctuation corrections.

I see now that dnf is show as simply “RWS (spelled out) Werk Nürnberg-Stadeln.” Interestingly, code dnh is shown as “RWS Werk Durlach.”

I stand corrected my friend. Thanks for setting me straight. I hate having wrong information. I suppose in a sense the “vormals Gustav Genschow” is not wrong, since it was the Gustav Genschow factory before RWS and GECO made working agreements, but I have corrected my own code workbook, which is one of the most used part of my library, to reflect your information and the actual entries in the “Liste der Fertigungskennzeichen.”

John Moss