Aluminium Swiss GP11


Hi to all,
can anyone provide me with the correct Swiss designation for this Aluminium cased 7.5mm GP11 ball round please.



Tony, I’m pretty sure this is a proof round rather than a ball.


Tony - I think this is probably a ball round. “Cartridge Headstamps of
Switzerland 1867 - 1985,” by Michael am Rhyn, published 1985, page
120, simply shows this cartridge as “Versuch” (experimental). They
make no mention of it being a Beschuß Patrone (proof cartridge), which
are covered on pages 124 to 127. During the early 1940s, there were
also aluminum-case 7.65 Para and 9 Para rounds, usually with the
M T headstamp, although one dated from the 4th Quarter of 1945 is
with the D T headstamp, as shown on your 7.5 round, and is somewhat
scarce. The aluminum-case proof rounds from Thun in the two pistol calibers
had the cases anodized bright blue.

Case metal supplier “M” on aluminum cases: Menziken
Case metal supplier “D” on aluminum cases: Dornach
Loading factory “T” Eidgenoessiche Munitionsfabrik Thun

John Moss


Many thanks Jim and John,
I am fairly sure it isn’t a proof round as examples I have do have a knurled rim.
I also have a aluminum case 7.65x21,headstamped,clockwise from 12 o’clock, 10 T 42 M and came to me with the designation of ’ Pist Patr 03 Avional’…now I have been unable to find a Swiss(German) translation for Avional but oddly enough a Bosnian one for aircraft??? maybe for aircrew use???
Thank you both for the information and it has been a great help as I am now cataloging my collection



This aluminium 7,5x55 cartridge was only a experiment


As for designation, I didn’t think there was a specific designation for 7.5x55 beyond simply “GP11”


I could be way off here - I am no metallurgist or scientist of any
kind, but I think “Avional” here may be a trademark name for some
specific type of aluminum alloy. Certainly the word takes its roots
from birds and aircraft terminology, probably Latin (I am no linguist,
either). I have heard reference in the past, possibly just slang, to
"aircraft-grade aluminum" and “aircraft aluminum alloy.” I have a
Swiss 9 mm Para label dating from December 12, 1944, overstamped
in red “avional Hülse” so whatever its meaning, it definitely refers to
the case material, not to its expected use.

John Moss


John is on the right track…
Avional (French) is an aluminum/copper alloy also known as #2017.


“Avional” is a Swiss trademark for Al-Cu-Mg alloys that was registered in 1927 by Aluminium-Industrie AG (AIAG) in Neuhausen, who years later also patented the process to manufacture cartridge cases. When it was put on the market, it was considered equivalent to German Duralumin made by Dürener Metallwerke AG.

Trademark registration:

Ad from 1939:




Many many thanks for the info guys…so I suppose I can ‘put this one away’ as Gew Patr 11 Avional much the same as the ‘Pist Patr 03 Avional’ ???



Back to John’s mention of a 9x19mm aluminum case round headstamped D 4 T 45 (April 45). It is an interesting headstamp since Dornach (D) only produced brass and Menziken (M) only produced Aluminum. The story of this round recently surfaced in Switzerland and reportedly is documented. In early 1945 the Thun Arsenal was converting 9mmP case production back to brass from aluminum. The last Menziken marked case known is M 3 T 45. Reportedly Thun was setting up or perhaps producing 9mmP with brass cups from Dornach when they discovered they had a quantity of aluminum cups in storage. The decision was made to run the aluminum cups through the machinery rather then converting back to aluminum again.

An aluminum case 9mmP exists (or did in 1986) in a Swiss collection headstamped D 4 T 41. I have only confirmed one specimen. The first M T headstamped 9mmP I know of is dated February 42. It seems likely that in 1941 Thun was trying out Menziken aluminum cups on their 9mm line for testing.

Tony, Your round with the D 2 T 40 headstamp is probably from some similar tests using Menziken aluminum cups on the production line for brass case ammunition. A very interesting round, even to a 9x19mm collector. Thanks for your post.




Slightly off topic, but was all 9mm production during this period aluminum cased? I have a box I recently acquired and I’d like to know what the cases are made of without opening it.


the swiss boxes contained aluminium cases are marked “avional”


Heljac, All Swiss 9mmP from 1942 through early 1945 (Mar 45) have aluminum cases as far as I know. I have never seen nor heard of a brass 9mm case from this period. I have the identical box to yours, same date on the front, and it contains aluminum case ammunition.

The same box style was used in the late `1940s loaded with brass case ammunition. The easy way to check is to weigh the sealed box, The brass case boxes, full, weigh over 200g and the aluminum case boxes weigh about 175g.

I checked about 8 of my 1943 & 1944 boxes, and none are marked “avional”. Perhaps that appears on some of the 1942 boxes, but I don’t have any from 1942 or 45.



From a well known and highly respected Swiss dealer, showing a note in the bag with a round from this box, which here is a photo of the box Xerox. (edited to add another photo of the box as the Xerox was folded when I first posted the photo)
Not sure what to make of the “false headstamp” comment, perhaps it’s just a translation quirk?


Pete - see my entry and Lew’s. I would not describe this in any instance
as a false headstamp, I know that was not your description, but I would
disagree with the Swiss Dealer on that terminology.

John Moss


box of the Aluminium Swiss GP11


Ammo Gun was kind enough to send me a link to website that contained the following images of boxes stamped Avional in red with a 1945 date. He also sent a photo of a 1943 box with the same marking.

Something new to look for!

Thanks Ammogun!



Lew, hst of the 20.1.45 box is probably 1 M T 45. I have a box of 22.1.45 with this hst.
For the langage mistake of the well known Swiss dealer, he speaks several languages, but is not known to write all of these…
The exact word is probably wrong hst.