13x92 SR Mauser Tank Rifle

I have this case with no headstamp.
Meassurement identifies it as 13x92SR.
Length: 91.73mm
Ø base: 23.06mm
Material: brass
Primer: Berdan

Can anyone identify the maker anyhow?

Together with the case I received this projectile. I belive that they belong together.

Ø 13.24mm
Length: 64.68mm
Weight: 52.49g or 810gr.
strongly magnetic
If there is a tracer cup or not I canot see because of corrosion.

Thanks in advance


Can you post a photo of the head with the cam focusing on it?

You mean the base of the projectile?


Nice find! Cartridges without headstamp are very hard to find in good condition. I don’t know who is the maker, but some attribute them to Germany (1930’s) and others to Belgium.



Yes, WWI German 13mm cases were all by Polte Magdeburg ,April November 1918, known. December rumoured but unconfirmed by actual samples.

Post-WWI possibilities are Sweden M21 AT, Soviet Union experimental AT and Maxim MG, and Thun Switzerland for China.
FN also made some ?1924?) for Baltic States, and possibly ROC.

Cleaning up the head of the case (where the primer is) will show up the headstamp if any.
POLTE WWI headstamps are a bit lightly stamped.

Doc AV

Desperado, I mean the case head.

Ok, there you go

Thanks! I just wanted to view it to make sure there is no faint headstamp.

Ok, thanks so far.
Some questions remain:

  • Am I right to say that pointing on a definitve manufacturer is not possible?
  • Is the definition of the caliber 13x92SR correct or has it to be renamed?
  • Regarding the projectile: Is it related to the case or not?



German sources from 1918 are scarce, most are from a later time.
A Rheinmetall drawing from 1934 identifies the caliber as 13 mm and case length as 92.0 mm. Therefore, a metric designation of 13x92R seems correct.
SR means semi-rimmed, but the case is of the ordinary rimmed type. I have to admit that Wolfgang Kern in his book used 13x92HR (HR = Halbrand = semi-rimmed). Manfred Stegmülller in the ammunition chapter of Kern’s book in my view correctly writes 13x92R. Stegmüller also writes that no tracers were found so far.

Nominal dimensions of the bullet according to the Rheinmetall drawing: diameter 13.2 mm, length 63.4 mm, weight 52.5 g.

The German official designation, according to a label on a casing, was “Tuf-Patrone” (as usual no caliber in the small arms cartridge designation). Tuf means Tank und Flieger (in the sense of anti-tank and anti-aircraft). The cartridge was intended for a Maxim type machine gun (Tuf-MG) and the Mauser rifle only a stopgap measure.