cartridge ROCK G83 M73

[orpheus72]

Can anyone tell me where this cartridge was used in and who the manufacturer (MPA) is ?

Details:

Height = 48,90mm
diameter = 20,75 (12 Kal.)

Markings are:

20 TP-T ROCK G83 M73
LOT 1 MPA 74

 

[Slick]

Geert

First guess: mortar ignition cartridge. Sadly, the only detailed references I have covers U.S. mortars, and nothing comes close to those markings. Might be a CAD charge.

Rick

 

[Bonnex]

I think Mecar used MPA for a while (Belgian as is FN). TP-T would normally mean something like Training Practice - Tracer.

I cannot be sure but maybe this is the propelling cartridge for a 20mm sub-calibre TP-T projectile for a Training Rocket for say, the Blindicide or a 3.5-inch launcher.

PRB (also Belgian) made a 20mm training rocket for a 3.5-inch rocket launcher and the 'round' was a 12g cart loaded with a solid slug with tracer, the case looks similar to yours.

Hope this helps in tracking it down.

 

[orpheus72]

I think Mecar used MPA for a while (Belgium as is FN). TP-T would normally mean something like Training Practice - Tracer. I have no idea really but maybe this is the propelling cartridge for a 20mm sub-calibre TP-T Rocket for say, the Blindicide.

Hope this helps in tracking it down.

Thanks.

I already tought it was a subcal of some sort (seen the 20 TP-T marking).
FN and Mecar are indeed based in Belgium, so MPA might be a designation from Mecar.

EDIT: Found the MPA marking on D. Lynn's pages confirming it as MECAR Belgium.
Further browsing the MECAR history i found this; MPA : Socite anonyme Belge de mecanique et d'armement site de Ptit Rœuls, Belgium

Rick: I ruled out a Mortar cartridge, as it does not have the small thicker belt a mortar ignition cartridge has (this was to ensure it could NOT wrongly been used in a shotgun).

Geert.

 

[Tony Williams]

I'm intrigued that the headstamp says ROCK. Might it have had some use in the mining industry? I know that some specialised loads have been used for such purposes. For instance, there's the Dardick Tround triple round.

As a matter of interest, there was also an item in the ECRA Bulletin in July 2009 concerning Winchester and Remington shotgun cartridges designed for blasting away the build-up of material inside blast furnaces.

 

[Andysarmoury]

It sounds as if your shell could have a industrial use, I have a 8 bore made by remington, that was used for industrial purposes
Andy

 

[smle2009]

I was thinking along similar lines but the M73 marking would suggest a military application to me?

Tony

 

[Tony Williams]

Could be. The military has all sorts of odd uses for 12 gauge. For instance, the M32 Line Throwing round used by the USN and Coast Guard. I think they have bird-scaring rounds as well, to clear airfields.

 

[orpheus72]

I Know here in Belgium the MECAR BLINDICIDE subcal rocket was used (see attached pictures)

The cartridge fits perfectly into the 'ROCK GUN' marked subcaliber round, but never heard that they used this kind of plastic cartridges for them.
In an old blindicide manual i have, the round used in that subcal is described as an aluminum cartridge with copper projectile

But seen the markings on the subcal: 83 -20 wich we also find on the cartridge.....

 

[AMMOTECHXT]

I believe that MECAR made a type of line throwing projectile that laid a line of det cord, for use in suspected anti-personnel minefields, to blow a clear path for troops on foot. That was around the time of the first Gulf war in 1991. The UK bought some on a sale / return basis. FN = Fabrique Nationale.
I may be mistaken. Certainly MECAR was mentioned in the description of the item, known as RAMBS 2 - the second version of a Rapid Access Mine Breaching System but it worked on the bullet trap principle and was for use with the UK SA80 5.56 mm rifle. Possibly it was similar to something MECAR made.

 

[Krt7.92]

In Belgian ammo ROCK is the abbreviation for rocket