Geco 9 x 23 Bergmann for use in 9 Largo guns


A box of Geco 9 mm Bergmann cartridge imported commercially into Spain in the '30s (I believe). These were for use in 9 mm Largo guns, which were in service in the Spanish armed forces and were popular for private use too.

This must be superb quality ammunition for the period, being non-corrosive and waterproof.




Schneider - a great box. Thanks for posting. At the time I did my book on the 9 x 23 mm familiy of cartridges
I was unable to find a picture of the Geco packaging for this caliber. It is a very scarce box. I hope this one is
not “in a box in your junk room.” : )


What happened to the “9” on the “KAL. m/m”, it seems to have been erased?


Looks to me like the “9” was in white, and the box is simply faded a little.
Most of these boxes were a light blue in basic background color, but I haven’t
seen this box before this picture, so really don’t know.


Do the 9mm Bergmann and 9mm Largo have exactly the same dimensions?


Falcon - a hard question to answer. A lot of the 9 x 23 mm cartridge types vary mostly in the diameter of the base. Spanish
cartridges in 9mm Largo, depending on when they were made, run a fairly large deviation in base diameters. Also, there is not
just one “9 mm Bergmann.” There are several variations, with the important ones being the 9 mm Bergmann Mars and the 9 mm Bergmann Bayard. The 9mm Largo is basically the 9 mm Bergmann Bayard, the cartridge shown in this thread. Again, though, you will find dimensional differences from maker to maker and era to era. They are basically interchangeable, but when trying to
sort them out by measurement, confusing! They are NOT the same as 9mm Steyr, which has a smaller base among other things.
Occasionally you will find a 9 mm Bergmann Bayard cartridge that is known to be just that, from box labels, headstamps, or other evidence, that will chamber in a Steyr barrel, but they are few and far between. When I was doing my book, I borrowed three Steyr Hahn (Model 1912) pistols, and tried every 9 x 23, of any designation, from my collection, in all three barrels. About 75% would not go into any of the Steyr barrels, and some would go in one and not another, due to the normal spread of cartridge specifications. I did not find any non-Spanish 9 mm Bergmann Bayard that would not enter a Star or Astra Pistol chamber, however.