Does anyone have information on 13mm Madsen Cartridge

My Madsen archive gives only a single hint of a “MADSEN machine gun, cal. 13,5 mm” in 1936. Even 13,5 mm ammo is mentioned, but no specific details.
Would be great to see this drawing.

I have a copy of a photo of a Madsen HMG somewhere - from memory, calibre 13+mm. Nothing on the ammo though.

I have 2 photos from Tonys files that are labelled Madsen Kynoch Contract

I will keep looking


Richard, these are 11.35mm.

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My mistake: my memory has conflated two photos I have: a 12.7 mm Madsen and a 13.2 mm Vickers-Berthier.

The 12.7x99 is then the Saetter machine gun from post 1945. It also existed in 7.62x51.

Yes, that’s the photo I have.


I will see if I can get a copy of the drawing of the cartridge. It would be great if you can post information on the weapon and a photo if possible. This would be a step forward since, as far as I know, Bill hasn’t identified the weapon.

All, Many thanks for looking! It would be great to turn up any information at all, even a reference to the weapon or it’s usage/application.

Thanks for the effort!


I misunderstood Bill. Following is his reply!

we have never seen a drawing, so have no idea what it looks like. All I know (from Peter Labbett) is that it was made by Kynoch late 1920s for Venezuela, and Berk Lewis said he saw one so labeled in an official display in Venezuela, but couldn’t examine it.

Bill has not heard of a 13.5mm Madsen cartridge either, but did mention that Kynoch made an experimental 13.5mm cartridge.


Looking a Kynoch Drawing data base I got from Tony Edwards I have only found these 2 entries

BK/82/189 Cartridge 13.5mm Kynoch cartridge 1.5.29 2504 FC. 3 R/R DRAWING
BK/101/33 Cartridge 13.5mm Kynoch Cartridge 27.1.30 1585 FC. 2 R/L DRAWING

They are late 1829 & 1930 dated so late 20’s and 13.5mm ???

I will try and find the drawings in the files


I can only find one I am not sure if its any help


The cartridge is the same overall length as the .50 BMG, but slimmer and therefore presumably less powerful.

The 13.5 mm Kynoch cartridge is extremely rare. Only two specimens are known to exist, both being dummies with a solder filled primer pocket, GM jacketed bullet with steel core, and no headstamp.

OT, but in case it is of interest: the 13.2mm Vickers-Berthier I mentioned. This photo is the only evidence for the gun which I am aware of. Anyone know more?

I have had the round in the picture for some time (shown next to a 50 cal for reference). It was recovered by one of my colleagues about 15 years ago from a garden in North London. It was very corroded and I used BIOX to remove the worst of the rust.

I have never known wether it was a genuine solid steel dummy or something someone had turned up on a lathe. With the thick rim it certainly looks like a Madsen type case. The round OAL is 125mm, the base is 23mm and bullet at the neck is 16mm but, because of the rust these are only approximate measurements. I would welcome any views from the forum as to wether it is original or not.

I hope someone manages to turn up a drawing it would be great if the dimensions roughly match.

I got a reply from a friend who is a former Madsen employee.
Unfortunately he has no details on the cartridge or gun as it was all long before his time.
The only thing he can say about Venezuela and a 13mm cartridge is that the 1924 dated export books do list the following items:
M19 cartridges
M20 belts
There is no info if this project ever was implemented or just planned/evaluated.

This much from a living fossil.

Recently I received further DISA/Madsen documents about produced weapons and prototypes. Among others, this entry (translated):

1930: MADSEN 13,5 mm in provisional trial-mount

So no doubt (to me) that they really had an experimental gun in a 13.5 mm caliber. The given date matches with the Kynoch drawing posted here before. But of course this can also be coincidence.

I remember that some (long) time ago, excerpts from Kynoch’s shipping documents were shown. In conjunction with 11.35 mm Madsen, I believe, but I can’t find it again and tell who it was.
So if anyone has access to these documents: an information of whether Kynoch has supplied 13.5 mm cartridges to DISA/Madsen around 1930 would be the missing connection in this case and of the greatest interest.


May be this cartdrige: 11,35 x 62 mm Madsen

Photo source: (bottom of the page)

Below is the same photo, with source information-

This is a PDF entitled Пулемёты (1931 г., Vliegtuigbewapening, Нидерланды-1)
Google translation to English: Machine guns (1931, Vliegtuigbewapening, Netherlands-1)

Page 394-

Selected text:
Een 13.5 mm mitr. is eerst kort geleden gereed gekomen en nog niet
in een vliegtuig ingebouwd.
Voor beproeving en demonstratie is het wapen voorloopig op een
driepootaffuit gemonteerd. Het gewicht (42.8 kg) is hoog; voor be-
wegelijke (waarnemers) bewapening dus
ongeschikt te achten.
Erzullen „slanke"’ (stream-line bullets) projectielen uit verschoten wor-
den, vervaardigd door de bekende KYNOCH fabriek te Birmingham.

Google translation to English:
A 13.5 mm mitr. only recently finished and not yet
built into an aircraft.
For testing and demonstration, the weapon is provisional
tripod mounted. The weight (42.8 kg) is high; for working
therefore local (observers) armament
not suitable to eight.
There will be “slim” (stream-line bullets) projectiles will be faded
manufactured by the well-known KYNOCH factory in Birmingham.


That texy is dutch not danish.