Earliest Geco 9 mm Parabellum box


Here is a picture of a rare Geco box corresponding to cartridges headstamped Geco * 9 m/m * and loaded with a round nose CNCS bullet. Note the use of two different “Geco” logos illustrated in the side panels. The one on the left is very unusual.

The label on the back was added by a gun store named “Armería San Martín” which was located at San Martín 284 street, Córdoba city, Córdoba Province, Argentina. The owner was a Swiss gunsmith named Santiago Aeschbacher.

Box of 7,65 para rounds needs identifying

Fede, You have done it again. I have never heard or seen this box. A wonderful item. I assume it is in the collection of the Association-would like to know for my records.

Do you have any idea on the date of this ammo. The combination of the Logos may give a clue. My guess is about late 1920s.

I don’t think this is the Earliest Geco commercial box, unless it is pre-WWI. My earliest Geco load has a Truncated Cone bullet and the case is dated Feb 1915. I would think any pre-WWI loads would have truncated bullets. The Geco * 9m/m * does occur with a truncated bullet so the headstamp could date from before WWI. I have no idea when Geco started producing 9mmP.

The earliest commercial Geco box I have is:

The loads have the military headstamp “Ge 10 D 18” and are a mix of 9 (Sep), 10 (Oct) and 11 (Nov) dates.

The earliest Geco military box I have is dated April 1917. Does someone else have an earlier one?

Can anyone accurately date the Geco * 9m/m * headstamp???

Again Fede, many thanks!



Lew, thanks a lot for this information. We often use the term “Geco” when refering to Gustav Genschow & Co. A.-G. products but what I mean to say is that this would be the earliest 9 mm Parabellum box showing the “Geco” logo illustrated. This trademark registration was filled in 1922 and claims use since 1919.

Does anyone known of any other box, catalog, etc. showing the “Geco” logo shown on the left?

PS: Yes, this is now part of the association collection.


Genschow became a corporation (Aktiengesellschaft, AG) in 1907. Before, it was named "Badische Munitionsfabrik Durlach GmbH, Gustav Genschow & Co."
Manuacture of pistol ammunition started in 1906 with Browning cartridges. "Production was expanded step by step to Mauser, Parabellum and Bergmann."
Source: booklet on the history of the factory by Elga Roellecke


Lew - I have the same commercial box for Geco that you show. However, the round I got with it is from Spandau, but dated 11 18 (latest I have or have seen, although I know from your books that you have 12 18). The cartridge has no primer seal and does not appear to have ever had one. Other than that, it looks like any other Spandau WWI round. I suspect that a round dated this late was probably never delivered to the German military - it certainly would not have reached the front before the Armistice. Since Spandau was not a commercial factory and no commercial packaging for 9 mm or any other auto pistol commercial seems to be known, at least not to me, I would guess they sold off these last “too late” lots, probably in bulk and probably to other ammunition factories or very, very large dealers. I doubt they would want to have been bothered selling off small quantities at a time.


The only Geco catalog I have from the 1920’s showing a 9 mm Parabellum cartridge is from 1929 (pre-Sinoxid) and illustrates a round headstamped K DWM K 480C with a truncated nose bullet. Also, the only cartridge illustrated in the entire catalog showing a Geco headstamp is a 6.35 mm Browning headstamped D Geco D 6.35, a format which can be dated as early as 1925.

Considering that a 9 mm Parabellum headstamped D Geco D 9 m/m without a Sinoxid primer would be pre-1930 and that this same headstamp format continued to be used when this primer was adopted, I would think that the Geco * 9 m/m * is most likely from the early 1920’s. However, I don’t have any proof of this and I don’t expect to find this caliber in a German catalog from that era.


Fede - Generally speakking, you will only find cartridges like the 9 mm Para in Export Catalogs from Germany. I believe these military pistol cartridges were probably not authorized for sale to civilians in Germany.

The earliest Geco commercial-style headstamp on 9 mmm Para is . G G & Co . D. and is known, I believe, from a single specimen in the Woodin Laboratory collection. There is also a * Geco * 9m/m headstamp that is very scarce. I don’t have it in 9 mm Para, but I do have it in 9 mm Corto (.380 Auto) headstamped * Geco * 9 m/m K with “O” Sinoxid primer. Lew shows this without an “O” primer on 9 mm Para as “probably in use as early as 1916.” That is possible, but based on my 9 m/m Short round, I am inclined to think it is from later than than, perhaps in the late 1920s and running into the eraly 1930s. In short, the “two-star headstamp” style could span a few years before and after the beginning of use of the Sinoxid primers with “O” on the cups. Just a guess. I have no documentation for it. Regretably, I had the box for the * Geco * 9 m/m K rounds, but it went missing on me a few years ago. I have not been able to find it since then. I do believe that the two-star headstamp predates the “D Geco D” headstamps, or else was made for some specific reason during the same time frame. It is not a common headstamp on any caliber of auto pistol cartridge that I know of.

Who Invented and Introduced the Sinoxid Primer and When?

Fede, I misread your posting. Those who correspond with me know that I have a habit of seeing what I think is being said, instead of what is actually being said. Sorry.

Thanks John for amplifying my comments on the early Geco/GG&Co headstamps. My comment on when the Geco * 9m/m * headstamp being “probably” used as early as 1916 is a mistake (one of many) and should have been “possibly” since it was based on the rounds I knew at the time all being RN bullets. I am a bit smarter now. Since writing that I have found truncated bullet loads with this headstamp both with and without Sintox primers. In addition the introduction of the “Geco” trademark in 1919 would indicate that any “Geco” headstamp must date from 1919 or later.

I also have the Geco D 9m/m D headstamps both with and without Sintox primers, all with RN bullets. Clearly John is correct that the loading of these two cartridges overlapped. From the Erfurt Conference of 1909, Genschow was allocated the “D” letter for their headstamps representing production at their “Durlach” factory. I have a 7.63M drawing dated 1925, of the Geco hst with the two Ds so we know the headstamp on 9mmP could have been this early.

An explanation for this overlap in production may be associated with the agreement in 1927 between RWS and Geco (applied in 1929 and on) that RWS pistol ammunition would be produced by Geco. Perhaps the headstamps with the stars were case production at another factory to supplement Geco capability. In the late 1920s, this could have easily been RWS until the turnover was implemented in 1929. The Star cases loaded after the introduction of the Sintox primer could have been cases produced earlier. Just speculation.

All the other pre-1945 Geco headstamped rounds in my collection have the Sintox primers except for the rounds headstamped Geco 9mm and Geco 9m/m with copperwashed steel cases which have plain brass primers.

Do we have an actual date when Sintox primers were introduced??? Did they entirely replace the old style primers, or were both available for a period???

I have a note that in 1920, Geco established a Buenos Aires agency in Argentina (becomes 'Geco Compania Industria Comercial S.A." in 1924).

Great info everyone! Many thanks.



Lew, in the “Sinoxid” trademark registration the Genschow company claims use since April 16, 1930. I don’t know if the old style primers were entirely replaced but at least there is a documented answer giving a starting date for any cartridge with a Sinoxid primer. I couldn’t find any earlier reference to this type of primers in pre-1930 Genschow, RWS, Dornheim or SB Schönebeck catalogs, but I’ll interested in hearing others opinions regarding this date.

The Argentine Genschow agency had many products specially made for them, including Geco brand rimfire and shotshells with unique markings, and also distributed some products made by Winchester, Remington-UMC, Savage, Browning, Colt, Walther and Smith & Wesson. In 1943 an Argentine company named FADA S.R.L. made a single shot bolt action carbine for this company which was offered under the Geco brand. The company was liquidated in 1945.

Thanks to everyone for their comments.

Who Invented and Introduced the Sinoxid Primer and When?

As far as I can tell the only dated 9 mm Parabellum cartridges that could lead to the interpretation of a contemporary use of the “old” and “Sinoxid” primers are those headstamped RWS 1932 (“old”) and P G V 32 (Sinoxid). Are there any other dated cartridges showing both primers?


Lew et al - The Gustav Genschow Co. A.-G. was really an international company as early, at least, as the 1920s. They had offices in many cities in Germany, as well as some abroad. Their 1933 “Munitions-Preisliste” (Price List) shows catalogs available in German, English, French, Spanish, and Portuguese.
In that catalog, their primary address is Hamburg, but they show offices in Berlin, Köln, Königsberg i. Pr., Franfurt am Main, Nürnberg and Vienna. For some reason, the Argentine connection is not mentioned, although that dates from earlier than this price list. This catalog also shows “Waffen-Fabrik in Spandau.” I found that interesting in light of the fact that my earliest Geco box, the same as one lew shows, had Spandau-headstamped ammo in it from
November 1918. I don’t know if the two, the fact of Spandau surplus ammo in a Geco box, and the mention of a Spandau connection in the catalog, are related, however. It is only offered here as a matter of interest.

The 1934 Munitions Price List (Export Catalog) shows the main address of Geco as Berlin, not Hamburg, although Hamburg is still mentioned in the places where they had offices. However, the 1936 catalog reverts to the Hamburg address line as primary It also shows ammunition factories at both Durlach and in Wolfartsweier and actually shows it as the factory for Hunting Ammunition, Pistol cartridges, revolver cartridges, Flobert munitions, rimfire ammunition, paper cases (assume shotgun shells for reloading) and Sinoxid primers. Durlach is shown primary as a lead-shot manufacturer. They also show a leather factory in Altstadt-Hachenburg and an Arms factory in Berlin-Treptow.

I have a nice little 1940 Geco Calenddr and fact book titled "1940 Notizen für
Jäger und Schützen (1940 Notes for Hunters and Shooters). It reverts the main address back to Hamburg and also notes offices in Berlin, Frankfurt am Main, Köln am Rhin, Königsberg, Nürnberg, Vienna, Rio de Janeiro, Buenos Aires, and Santiago de Chile. Factories are shown at Durlach (ammunition and shot for hunting), Berlin-Tretow (Arms) and Hachenberg (leather wares). The Wolfartweier factory is not mentioned in this booklet.

I have a little two-page ammunition catalog in Portuguese, unfortunately not dated, that offers only the 6.35 mm Browning and 7.65 mm Browning cartridges. The company name on it is Sociedade Geco Limitada, Rua Theophilo Ottoni 35, Rio de Janeiro, Brasil.

Hope this is of some interest to those with an interest in Geco and its history.

Edited to correct my atrocious typing!

John Moss


Try to make a shrt history about Geco.

25th August 1887: Founding of Gustav Genschow & Co. under the basic principle; “delivery only to resellers.” Founder is Gustav Genschow from Stralsund

1899: Participation in the Badischen-schrot and Gewehrpfropfen factory Durlach

1903: Acquisition of the Durlacher Zündhütchen- und Patronenfabrik GmbH

1906: Melting of the two companies in the Gustav Genschow & Co. as well the establishment of the first branch in Cologne

1912: Establishment of a specialized branch office in Vienna for export transactions to Austria-Hungary and the Balkans

1921: Establishment of another branch in Königsberg / Prussia and the new organization of the sales departments in Frankfurt / Main and Nürnberg

1924: Akquisition of the Deutsche Werke Aktiengesellschaft. This was the only specialist factory in Germany for small caliber weapons. Foreign business flourished at that time, including in South America. In nearly all South American countries were Genschow pistol cartridges used for the police forces.

1927/28: Forming of an interest-community with the RWS and the Dynamit Aktiengesellschaft vormals Alfred Nobel & Co ., the largest munitions factory in Nürnberg. Production of rim fire and Flobertpatronen, revolver cartridges, metal cases, primers and air gun pellets in the works Fürth/Stadeln und Nürnberg

1940: Death of the founder Gustav Genschow

1952: Resumption of production of hunting and sporting ammunition (rifle bullets, shotgun shells, in 1957 for pistol / revolver)

1963: the transition of the entire plant of Genschow & Co. Aktiengesellschaft into possession of explosives and munitions factory Dynamit Nobel AG

1966/67: Consolidation of brands GECO, Rottweil, RWS under Dynamit Nobel AG

1972: Relocation of the company from Durlach / Karlsruhe to Fürth / Stadeln

2002: Acquisition of Dynamit Nobel AG by the Swiss technology group RUAG



Dutch, Your comment on Geco acquiring DWA is interesting since the box for 1920 & 1921 DWA 9mm indicates the “S” (which I assume is Spandau) was the case manufacturer for the DWA cases. The bullet maker is “M”. The primer is by “Sp” which I again assume is Spandau, and the loader is “D.W.Sp” which seems to me to indicate that DWA and Spandau were the same activity in 1920 and 1921.

Perhaps this is something that was already well known and I am just figuring out the obvious. I have seen Similar DWM marked boxes from 1920 & 1921 identified as DWA boxes, but these actually contain ammo marked “DWM K 480C K” with serifs (hst DW03F in my headstamp guide).

I have five of these DWA boxes with Spandau markings dated 11, 23 and 24 Dec 1920 (they worked Christmas Eve), and 25 Feb & 24 Mar 1921. Four of them have DWA loads in them and and one (Marz 1921 pictured) is empth. Three of the boxes are full so their is little question that they are the correct boxes.

I just opened the 25 Feb box which was sealed until about 10 minutes ago, and it contains 15 mixed DWA 11 20, 12 20 and 1 21 headstamps, and a single “S 9 18” headstamped round so not much question that the “S” is Spandau. Like John M, I cannot stand the suspense of a sealed box.



The Geco/Genschow history has been discussed before:



The government owned military factories at Spandau had to be destroyed as part of disarmament.
Deutsche Werke AG was founded to keep at least a small part of this alive. It resided in the same area as the former government installations. No wonder that Spandau cases show up in Deutsche Werke boxes.
A history of Deutsche Werke has yet to be written.


John, I was going through my stuff and I also have a Gustav Genschow & Co box identical to the one I illustrated, but this one is filled with S 11 18 loads except for a one S 9 18 and a few S 10 18. I do not have an S 12 18, but Randy Elzea reported that he had it. I have not checked his collection at the Woodin laboratory to confirm this. I have no record that I have actually seen an S 12 18 dated round.



Lew - I thought you had the S 12 18 round because of the way it is entered in your book.


John, I mentioned errors! It should have been entered 12(3).



Fede - Back to Sinoxid primers, I find the earliest dated RWS round I have which has a “O”-marked Sinoxid primer is a 9 mm Kurz round dated 1931. I have several rounds in different calibers with this primer from 1932, and also some 1932-dated rounds with plain primer, so evidently there was a cross over period of a couple of years, since there is a note on this thread about a claim for this primer from 1930. The R.W.S. 1931 round is odd in that there are periods after each letter in R.W.S. I don’t say that doesn’t exist on other cartridges, but it was not the norm for the “RWS” to be punctuated. I am not considering as punctuation the dots that appear on Geco and RWS ammo in various places and various quantities (one thru four total, appearingly individually before and after the other entries on the headstamps. These are probably a date code, which to my knowledge, has not been interpreted yet.


John, we seem to go over the same topics time and again.

Here is a discussion on the RWS “dots” which I believe to have been used to indicate different manufacturing lots (eg by Norma), not date codes as there aren’t enough variations (certainly on RWS examples).


Here is what I have on the Sinoxid primers and I am sure this topic has been discussed several times before also:

The date of introduction of the Sinoxid primer is often confused with some references saying: 1916, 1926, 1925, 1928 and even 1932. The truth is that the SINOXID primer was patented in 1926 [Ed : Ref rottweil-munition.de].

RWS first started the development of a rust-free primer in 1901, at the plant in Stadeln, Germany. The ammo made in the Stadeln plant has had a non-corrosive primer since 1910, although not the Sinoxid type. This used a “U” primer marking (U = “Utendoerffer” ?) which was used until 1905 and then a “R” marking was used.

RWS introduced the first commercial mercury-free rust-free primer which it called “SINOXID”. The first loading in cartridges was made for military use in 1926. The name Sinoxid came from a prize contest to name the primer. The first spelling was “Sinoxyd,” but was later changed to the still-current “Sinoxid.”

The Sinoxid primer used an “N” marking. The “N” stands for the RWS "N"urnberg factory. Indication of the use of the patented Sinoxid primer is noted on RWS packets from 1928 (Heinz Held) and catalogs from at least 1931. There are also primers with “SINOXID” written on them which were predominately used for shotshells (see images).

The M+F Thun later acquired the license for the use of the German Sinoxid priming.

Who Invented and Introduced the Sinoxid Primer and When?