10mm Mars. Fake or not


I have asked a few friends already and 70% saying it’s a real one, rest of them saying, don’t know. What do you think ?

Rim is 12,34mm Head is 12,52mm Neck is 10,72mm Bullet is 10,16mm Case is 25,12mm


I understand that this is an unheadstamped case, but a photo of the case head would help the experts render an opinion!


I will try to get a photo of the case head later today and “yes” it is without hds.


I have none to compare it to, but I only remember seeing MARS rounds, in a few different calibers, with CN jackets, not GM.
I think John Moss needs to make an appearance here.
Ditto on the need for a pic of the base.


I will make an appearance, Jon, but not sure I can add anything to it. Admittedly, neither the bullet nor the case-mouth crimp is what I would expect to see in a MARS cartridge. I have never seen an original (confirmed original, that is) 10mm MARS round, so it is hard to say. The only one I have is a NUPE case, headstamped, that was made by Kynamco (? - some say Bertram) for cartridge collectors. The hole in the case tells us nothing, as I had an original MARS .45 Long dummy with a similar hole, and snapped primer. It was felt to be original. In a weak moment, since I had the live cartridge as well, I traded it to Jim Tillinghast for a whole lot of good rounds. He agreed with some other good sources that it was a legitimate dummy, and the circumstances surrounding the acquisition by me would not make me suspicious (no claims of orighinality or not, same price as a live one which wasn’t any big money then, etc. Of course when I obtained it, I had also just purchased my live one for the then-going price of $20.00.


Jon, as I am usually do, enlarging the fotos or captured fotos from the object by about 20 times, it mostly reveals fake headstamps (engraved, ciseled or similar ways) to one point. But here, the “hole” in thr case shows clear, that it was drilled in after the “staining marks” on the case where already there. And secondly, that the tooling, the drill hole was made with, was



I have exactly the same cartridge in my collection and I have seen 3 of them in France.

I think it’s a 10 mm MAS (Manufacture d’Armes de Saint Etienne).

From 1901 to 1910, the MAS made trials to develop an automatic pistol. One of these 10 mm pistols is in the MAS Museum in St Etienne.

(I am sorry for my poor english).



Chassepot - what is wrong with your English? What you wrote was near perfect English. You communicate excellently. Thanks for reminding us that not every cartridge given one name by its owner is a fake if it is not that cartridge. I don’t know if this is a 10mm MAS or not, but there is always the possiblity of a cartridge being genuine but simply not the round the owner thinks it is. The MAS pistol pictured looks heavily influenced by Mannlicher’s designs, I think. Interesting. Merci.


Hello Chassepot Your English is much better than my English but we are not going to discuss that. :-)
I am little bit confused about the name her. 10mm MAS, MAS is what I know French but the photo of that pistol are very similar the Mannlicher pistol / carbine as John M. are saying. I know I haven’t heard or seen everything, BUT I have NEVER heard about MAS or Mannlicher pistol in 10mm caliber so this her is very interesting for me. This other rounds you have seen, are they with a hole in the case ? I guess not but need to ask.

It was a little difficult to read all from the drawing but what is it saying about the bullet diameter / Case mouth, inside 10,1mm and outside 10,5mm, is that correct ?
The rim and head diameter was “what I would say” the same. My round is a berdan case too. I got this round from a collector ho had it in his collections for more then 30 years.
So how big chance is it that some people did make fake/home made rounds before 1970’s ?


Hi Jon, i havent said, that cartridge is a fake…just said: The hole was drilled in, after the staining spot was there…

From the 10mm MAS exists a lot of “Copies” made for the french Cartridge collectors club. But they are identified by a special hs and mady by MEGRET.
If the dims from Alex cartridge goes with the dims given in the old MAS-Drawings, its may such a “fausse cartouche” for function tests. The fausse cartouche was usually just with a snapped primer…The hole in the case can than be attached later on, to go with the french rules (a snapped primer alone is no deactivation in the french law, as you still can use (re-use) the case)…and that also would explain, why it is “over” the staining spots…



Here I got a photo of the case head


Fakes have existed since before the 1970s. In California, we had a large number called “Grass Valley Fakes” from the town the person making them came from. I have seen even the MARS Pistol rounds that were the guy’s fakes, and they would have fooled me at that time. These date from the 1960s, I think. Certainly earlier than 1970, as they were known before I got into cartridge collecting, which was about 1960 or 1961. He got caught because he reproduced a Chinese headstamp from a photo. Great job, except the photo was badly printed and made the headstamp look the opposite of what it was - I forget which. Either the photo looked like a raised headstamp when it should have been stamped in, or the opposite.

Sal Guarini had a lot of these fakes pulled apart so people could see inside and get some idea of why they were fakes. He would only show them, as I recall, to people he knew, as he was not giving classes in how to make fake cartridges.


This would be an interesting topic for a future St. Louis seminar.




The neck(and mouth) -diameter of 10,72mm of your cartridge corresponds very well with the drawing (which gives 10,8 (thats a deviation of 0,08mm!! only which is well in the range of the usual diameter-variations in production-even today-.
Your bullet diameter also corresponds well with the given diameter (at base of the bullet with 10,3mm). As you already take measurements at the end of the neck of the case, the given 10,16mm from you are IN THIS range.
The rim is also beveled, as in the drawing…
So, I go with Chassepot , your cartridge IS a 10mm MAS cartridge, for the essays with that Mannlicher-Typ pistol from the St.Etienne Museum.



It is for sale,
Send PM if interested.