13,2x99 Hotchkiss history

Anyone have any data for the ap round btw? All the data i have is the velocity which is 820 m/s

Tony, the projectile used in the 13.2 was not the MG131 type. As you remember the MG131 used a separate driving band while the 13.2 had a unique design where the steel body of the projectile formed a thicker portion and engaged the rifling with the bare steel body. This actually could be the reason why the Germans had no (known) AP types in this caliber.

Thanks for that correction! I should have checked the 13.2x93 HE in my collection more carefully…

Also some swedish data i have says that the ap projectile had 12 mm pen on a 60 degree slope at 200 m

Romania also produced this cartridge:

Did they actually produce it? I thought they only had a handfull of 13,2 mm FN m.1939 guns which where replaced rather quikcly with the mg151.

Alex, Do you have any data on the German Hotchkiss loading - projectile weight and MV? Also, what designation was it given?

Some years ago I received a message from a Frenchman concerning a rather different history of the 13.2 mm Hotchkiss (apologies, I did not note his name). The message was as follows:

First of all, I want to specify that there is no relation between a. 50 BWG [presumably BMG] and a 13.2 x 99 Hotchkiss ctg case! The first Hotchkiss researches for a heavy machine gun ctg started early 1901 in relation with S.F.M. and the original ctg was more likely a scaled up 7.92 than any American one. Main improvements were carried out after WWI with the adoption of a variation of the 13 mm Tankgewehr ball. The final tests were ended early 1925.

Why two case length ?

After the adoption by the french Navy of the 13.2x99 mle 1930, once noticed that barrels had a too short life . A competition between the three ammunition factories in charge of the production started ; each studying the possible improvements. It was Cartoucherie de Valence, Manufacture du Haut Rhin and Société Française des Munitions. A detailed report of each improvement of the three factories will be out of subject and very long but one was effectively a better improvement. Its specificity was the adoption of a large groove in the medium, cylindric part of the ball. But , due to the position of the groove, it was for reasons of manufacture impossible to crimp easily the case neck. The only solution was to shorten the case neck and crimp it in the upper part of the ball groove. The case lengh was then shortened of 3 mm, the new cartridge was adopted as 13.2x96 mle 1935. Groove and short case are concomitant.
Note that the two ctg length can be used in the same barrels and that the two case length continued to be manufactured in the different manufactures, even after 1935.
The reduction of the case length is for manufacture reasons and NOT a question of distinction with the .50BWG case. In the 1930’s , the Hotchkiss 13.2 had a world wide extension than the .50 BWG and could be used in Hotchkiss MG , Air cool and water cool Browning MG , Breda and Scotti MG , Japanese Hotchkiss MG.

I did not take this very seriously when I received it, but wondered if there could be anything in it…?

In case it came from Philippe Mention I would consider it to be most serious data as he is digging French archives up and down for the 13.2mm Hotchkiss project.

Tony, I do not have the manual for the German 13.2mm ammo and also do not know anybody who does.
This is one of the few manuals we are missing for some unknown reason.

This includes the manuals for the German:
13.2mm Hotchkiss
2.8cm s.PzB. 41 (28/20mm squeeze bore)
37x250R C/36 (M42)
37x252R Flak DA ®
128mm KwK
800mm Dora
And sure some others.

Not Philippe, I know him!

I wouldn’t have thought that anything that size would be lost very easily!


The German Bundeswehr hast lost tanks and aircraft in their inventories. So what is a manual in wartime?


Oops - this is where I need an emoticon with a very red face…I contacted Philippe, and he told me that he had indeed sent me the original information I posted above!

This is fascinating, since it shines a completely different light on the history of this round. Philippe tells me that he has accumulated a great deal of information on the round which he may be posting on his aferhm.org website in due course.

Ok here is the 13.2+99 and 96 they both seem to be the same yet they are not the
difference is in the necks.There is supposed to be a variation in case lenght but there
seems to be little 99,24 to 99,08mm.they would be difficult to differentiate if it would not be for the
neck.they are both incendiary tracers and the bullets are different too,one is cupro nickel
the other seems to be copper washed steel.

Hi Sherryl,

The cartridge shown in photos 3 and 4 is a 12.7x99mm (.50BMG) AP from the Dominican Republic.


Well yes you are right,a half a lifetime ago I was sold that round as the short Hotchkiss,but at
that time I had no means to verify it,so I left it alone till now and done some checking after
reading your post,and found out that now I have a new headstamp for my 50cal.BMG
well that is the way it goes at times.


Hello, below is on the left a 13,2x99 and on the right two 13,2x96, you can see the large crimp which start just above the shoulder.


Here are a few 13,2mm Hotchkiss cartridges and two boxes.

13,2 box


Excellent! Thank you very much.


I do not have a collection as wonderful as Rigby and the rest of you, I have at least one round to add to the list. It is a Italian produced HET round from 1940 used in the Swedish Airforce.

This round is deactivated, only to close the discussion :)