9mm Steyr or Bergmann-bayard, which is it?

Since both the Bergmann-Bayard and Steyr cartridges fall within the same range of measurement (which this one does) it appears that the bullet weight is the telling factor. That I don’t have. Does anyone have a comparative total weight that I might use. This weighs in at 186.5 grains or 12.08 grams

9 m/m Steyr. If this cartridge were loaded with the Bergmann bullet it would weigh about 200 gr.

Although not conclusive, the Austrian headstamp would lead me to Steyr.

And the Bergmann round generally has bullets with a blunter ogive. Jack

I researched the 9 x 23 mm rounds for several years. There is no question that your cartridge is a 9 mm Steyr. While sometimes interchangeable, the Bergmann-Bayard and the Steyr are not the same case. While working on a book about the 9 x 23 mm family of cartridges, I tried 112 9 mm Bergmann-Bayard cartridges from my own collection in three barrels from Steyr-Hahn Model 1911/1912 pistols, with one of the barrels withdrawn from the study as, much to the chagrin of my friend who supplied the barrels from guns in his outstanding Steyr Pistol collection, we found that barrel had been reamed out to accept 9mm Bergmann-Bayard rounds, and poorly done to boot. Of the 112 cartridges, only about 1/3 of them would fit the other two Steyr chambers, and some of those were actually too tight to be considered a proper fit,

In my study, I found no Bergmann-Bayard cartridges made in Austria, by any company, including the G. Roth A.-G., the company that made the round pictured on this thread, and Hirtenberger. All Austrian-made cartridges of 9 x 23 mm were truly Steyr rounds.

Since the Bergmann-Bayard is normal with bullets of approximately 135 grains (a well-thought of published source shows 134.26 to 137.34 grains), overall cartridge weight can be used to determine which of the 9 x 23 mm rounds is at hand. However, there are problems with this. Steyr bullets are reported as being from 114.20 to 118.05 grains. But, there are exceptions. The overall cartridge weights determined by the weighing of every 9 mm Steyr and 9 mm Bergmann-Bayard round in my collection for a spread of 177.2 - 195.1 grains for the Steyr and 195.4 - 204.09 for the Bergmann-Bayard. Some rounds were excluded as being non-typical. For example, the Bergmann-Bayard rounds by Midway Arms, so headstamped, have a 124 grain bullet, but a total cartridge weight of only 188.6 grains and a 9 mm Largo round was found that had a total cartridge weight of 190.1 grains, but is identified by its headstamp as “9L” indicating “9 Largo,” the Spanish name for the Begmann Bayard cartridge. In short, identification by overall cartridge weight can be misleading.

All factors - country of origin, overall cartridge weight, bullet weight if known - must be considered. In my “experiments” which including pulling bullets from many duplicates to my collection, by the time my book was written, I had moved four or five rounds I originally identified as being Steyr to my Bergmann Bayards, and about the same number in the other direction.

All part of the learning curve, and perhaps the most frustrating, but still the most fun, study I ever did on sorting out cartridges by the intended “caliber.”

John Moss

The reference I have is White & Munhall, Pistol and Revolver Cartridges, Vol. 1. The comparison they do on the two gives the B-B with bullets of 125gr. - 136gr. and the Steyr 114 - 118gr. Also they note the case taper of the B-B as .010 - .016 and the Steyr about .007. The taper on this round is .004. So that, with what John and Jack have offered pretty much nails it down to the Steyr. Not in my bailiwick at all (sorting someone else’s stuff) so a big thanks all for the help - really appreciated.

There is simply no question that it is Steyr. As I mentioned, I have seen no evidence in 57 years of collecting this and other auto pistol rounds that any 9 mm Bergmann-Bayard rounds (or other 9 x 23 mm types) were ever made in Austria, including by G. Roth A.-G.


Yes, this is quite rare civilian version of common 9 mm Steyr round from Georg ROTH factory .
No military headstamps of this sample from GR are known.

Were all 3 GR headstamps,
GR / * / * / * /

  • / GR mono / * / 892 /
  • / GR mono / * / 696 /,
    civilian versions? Looks like John is replying…Good!

There are three of these G. Roth A.-G. 9 mm Steyr headstamps. The other two headstamps are the same except for the 6 o’clock position. One has the G. Roth case number 892, proper for the 9 mm Steyr cartridge. The other has the number 696, which is actually the Roth case number for 8 mm Roth-Steyr. I assume that the second was a headstamping error. I have all three of these cartridges so they are confirmed.

Reference: “The 9 x 23 mm Rimless Pistol Cartridges”, John Moss, Woodin Laboratory, page 60.

I agree with THV that all of the three headstamps are likely from commercial sales. I have never seen a G.Roth A.-G. 9 mm Steyr cartridge headstamped in a military style.

Dan - I will go ahead an post this, but it duplicates your answer. Sorry for that. I was almost ready to post when your answer appeared on the screen.

John Moss

Thanks John, I seen you coming.
My first star got changed to dots. Some auto incorrect thing…
Also, I think the 892 is the highest known Roth number.