Argentine subcaliber rifle for artillery

This is an Argentine Model 1891 Mauser 7.65mm rifle converted for subcaliber use.

The “rim” diameter of the sleeve over the chamber area is about 50.4mm and the forward edge about 49mm.

Can anyone help ID the caliber of artillery piece this was made for, possibly a 37mm tank/anti-tank gun? Did the sleeve fit into the chamber, or was this made to fit into a cartridge case for a larger caliber tank gun?

Thanks in advance.

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If you measure the Muzzle bush, you will find it is an insert for a 37mm AT gun. Probably the US model.
The rear sleeve locks into the chamber, ( without the original breech block but with a special replacement breech lock.)
They used (?) specially 7.65 Trace projectiles, loaded to simulate ballistics of 37mm gun.
Many countries used this subcalibre system, starting with the Morris Aiming Rifle for large calibre Naval Guns and Land Artillery in the 1880s.( 1" Nordenfeldt cartridge)
With smaller artillery, rifle actions were adapted for subcaliber use.


Fede !!! Help us, maybe for Hotchkiss or Vickers Amstrong 37mm used by the argentine navy ?

Interesting, I saw this at our gun show two weeks ago, it belongs to the NRA emploee manning their display table.
This should more accurately be called a Spotting Attachment, because it was clamped onto any number of larger guns aboard ships.
These were made for both the Springfield 1903 and the Springfield 1898 Krag… [cropped to remove his face due to ID permission]

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Jack, the term you are looking for is “aiming rifle” I think.

Aiming Rifles, such as Krag and some Springfields, were for Outside Gun attachment ( see Brophy)
But the Morris device was for in the barrel fitment.
The M1891 Argentine adaption is for inside fitting…note forward bushing of correct Bore ( Land) diameter.

Doc AV

I’m curious about the terminology on this - in the US generally subcaliber is a term used for training devices. As such, most US subcaliber devices are mock projectiles with an internal gun barrel, used to fire a small caliber projectile but with the same handling and firing procedures as the real round. The only exception I can think of was the US use of the German 14.5, but that was an exception. Is this item intended to be used like the 14.5, or is it intended for bore-sighting, spotting, etc?

John, very interesting piece, thanks for sharing. This conversion was called “economic tube” and was used by the Argentine navy in several artillery guns having different adaptations. Ammunition was of the standard ball type, not tracer. They even made a variant in 7.65x61.

Please, can you post pictures of the markings?



Hola, Fede,
Seeing you mentioned use of 7.65x61 in Armada Argentina subcalibre use,
can you find me original chamber/
cartridge specification drawings for the 1914 MA 7.65x61?
I have a M1909 Rifle With chamber
US importer-modified to Cal .30 M1906 …I wish to adjust the chamber to proper
7.65x61 MA…I already can make
Very close approximations of the
MA cartridge using my existing dies etc.
From comparison of photos of
MA and Cal.30, it seems that the
MA was developed by combining
The profile of the 7.65x53 case shoulder and neck, with the longer
Cal. .30 case…from experiences of the AA rifle team at the PanAmerican Matches in USA in 1912 or so…
Ball’s book on Mausers shows an Argentine M1909 fitted out with a US Springfield type stock( no pistol-grip and lenghtened forestock) and the special M1903 windage adjustable rear sight. No cartridge details except
“7,65” are implied in the ID of this rifle.
Have you any photos of the AA MA
Rifles? I Would assume that the
Rifles of the Rifle team woukd be
the modified ones?
I have been to the Museo de la Nacion, but couldn’t see a MA rifle there. ( maybe I did not look hard enough-- too many interesting to see, and not enough time…even a week would not be !enough!

And with the decline in Matches etc. During WWII, the MA rifles were converted to Subcalibre devices???

Muchas gracias y saludos.

Doc AV, the Navy wanted a new service cartridge for their Model 1891 and later also Model 1909 rifles and tubes without any modifications except for the chamber; it was never conceived as a match cartridge. In their experience the regular cartridge suffered from certain deficiencies noted after Camp Perry 1913. To my knowledge, no rifle has been identified so far.



Yes, that is what I meant when I said ‘Spotting Attachment’, and, while the inscription clearly states SUB CALIBER ATTACHMENT, if you look at the book, (which I made note of neither title nor auther), the chapter is titled ‘Sub Caliber Rifle’, and in the various pictures, and descriptions, they do not differentiate between those that go into the barrel and those that clamp onto the barrel.

The book indicateded that they were used both as a training device and a soptting device.

The book indicateded that they were used both as a training device and a soptting device.

Thanks -