8 mm Ultra

Hello guys,
does anybody have (at least) the picture of 8mm Ultra (Geco 1934) box?
I have added recently this cartridge to my collection but can’t find much info about this caliber nor the picture of the box. (picture of my Ultra’s below)
Thank you



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First time I ever see this 8mm round and you ask for a picture from the box!!! :-)

Great round, thanks for showing.


Nice Find.
On the 8mm Utlra by GECO picture are they a modern reproduction by GECO of Germany? or from the 1934 era, if 1934 era they are in GREAT condition…
Here is information I found on this caliber; " Introduced in 1934 by Gustav Genschow & Co. of Karlsruhe-Dulach for a pocket pistol with some Walther’s PP pistols chamber in it." per Brandt.Muller’s “Manual of Pistol and Revolver Cartridges” Book .
Any picture of the box available ?

Both the headstamp and primer (Sinoxid) on the 9mm Ultra are 1930s vintage.

I have never heard of a box for either, but not my collecting area. The 8mm Ultra is a particularly rare item.



Thank you all… my pleasure to share the pictures.
Both shall be 1930’s originals.
Does anybody have at least the 9mm Ultra box picture? (the old one…not from 70’s or younger)

Thanks Trabi_Fun!
It is interesting to me, that they have different bullet jackets, one has 2 dots, and they are spelled ULTRA and Ultra. Very nice! Thanks for posting.

Is the 8mm a semi-rim?

Hi Alex,
yes, you’re right…it’s semi-rimmed.
Rim dia - 9.2mm
Base dia - 8.8mm
RGDS Tomas

Thanks Tomas!

There was a plain box in the crime lab, ones filled with 24 cartridges (one missing), from which where 19 rounds fired to obtain ballistical data…what a shame for the collectors…
Here the ballistic data obtained by this occassion…
see pic of data sheet from Ex-DDR Crime lab


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In my opinion, while the collecting community doubtless will feel a painful loss, History of Technology has gained extremely valuable hard facts (due to being measured by professionals) about this obscure cartridge.

Jochem, while understanding your point I wonder if it really takes 24 rounds to establish the average Vo and other data as the ballistics of this round hardly matter that much to the rest of the world.
Otherwise it would imply that we also should do crash tests with 100 year old cars (of which less than 100 do exist) to find out their performance in this regard.

But my remark here shall not be the start of a lengthy discussion of the pro and con as it is all opinions only and as we all know everybody has one and is entitled to.

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Peter, thx for posting. Interesting info.
RGDS Tomas

Verschossen wurden 19 !! Patronen (nicht 24 extra erwähnt), bzw nur 17, weil 2 eben zerlegt wurden für Einzelteilmessungen und 1 Schnittmodell.
Das sind gar nicht soviel Patronen zur Ermittlung von Gasdruck und Geschwindigkeit.Bei älteren Patronen gibt’s grössere Schwankungen, als bei “Neufertigungen”

There where not 24 rounds fired (read the text)
There where 19 Cartridges missing from 24 and of that 19 where 2 taken apart to get one Cut and one for measurements- Both (cut and pieces) and the rest of the box are still there…)
A number of 17 shots for establishing velocity and pressure is not that high…
Go and look ones into the ballistic lab of RUAG or S&B…


I share Peter’s view and in my own velocity tests or when I pay an institution for a pressure test, its at least 15 rounds (provided I have that many) to obtain a reliable figure. These institutions usually ask to provide 2 or 3 additional rounds, because sometimes a measurement is faulty.
While we can get decent data about an old automobile by simply driving it without a crash test, our pet subject ammunition forces us to eat the pudding to learn its taste.

All what you both are saying is correct.
But shooting 30, 40 or 50 year old ammo to do ballistic tests is like trying 1 week old bread for it’s taste.
Both a waste.
And what does the Vo of the 8mm Ultra help us (despite to likely be incorrect anyways)?
Noone is using it and no guns are around. The only value in this cartridge is it’s sheer existance.
I would not question it if there would be plenty 8mm Ultra around like with many other experimentals where shooting away some 20 rounds will not change anything.

But as so often, everybody has his own view on why and how he is approaching the ammo subject.

Lew - I am sorting thru various topics I missed when my computer was down for so long. I, too, have never seen a box for the 8 mm Ultra cartridge, although I have a specimen of the cartridge in my collection. The 9 mm Ultra box has been pictured in an old “Gun Report” Magazine, as I recall, and in some other places. It is nothing more than one of the Gustav Genschow & Co. A.-G. 25-round blue boxes with some black and some white print, for the 9 m/m Kurz (.380 Auto) cartridge, the box with a red diagnol banner in the upper right corner (as you view the top of the box) with “Oeldicht” in yellow letters printed in it). The only indication of the Ultra caliber is a small white tag with the word “Ultra” (as I have typed it, with the tag including the quotation marks) covering the word “Kurz” on the original box-printing.

Still, it is a rare box. Wish I had one!

Edited to clarify a statement in line two of my entry.

John M.

John, If the 9mm Ultra box is just a commercial box with a Tag on it, an 8mm Ultra box may not even have achieved that basic recognition. Thanks for the info! There always is the chance we will all be surprised on this topic someday.


Lew - it would be nice to have more information on that caliber some day. The information about there only being one lot of the 9 mm Ultra ever made proved to be absolutely wrong. There are three variations known of the cartridge - I have two of them. In fact, I had an article in the IAA on this subject.

The common wisdom is that there is only one pistol known in this caliber, and I believe that one was owned by the fellow who wrote the books on the P-38 Pistol (Warren Buxton? - am waiting for the arrival of a fellow to fix my printer, and can’t hear the door bell if downstairs in my library, hence the guess).

John M.