Really Unusual 120mm APDS Item That Makes No Sense At All


I recently purchased this unknown 120mm APDS related specimen. It is incredibly well built and engineered which makes me believe that it is probably not a amateur art or science project. I was told that it was a special built tool used in the early development of a APDS round. It doubt it was made to be fired as there are a lot of small external parts and this type of wiring does not look like it could withstand the forces of being fired. It has what looks like a very heavily built camera iris inside that has its aperture controlled by and external knob. The part that has the wiring in it reminds me of an old VCR recording head, only a lot bigger. Anyone have a clue on it?



Aluminum parts (easily machined) from a 120mm APDS that were repurposed for some unknown R&D project or test???



Other then maybe the VCR recording head looking part, the main body is all steel. This thing is heavy.



Maybe a wind-tunnel aperture / diagnostic tool of some sort for measuring flight characteristics of various different-shaped penetrators in observable airflow?

My collector senses want it to be some sort of super-secret radioisotope thermoelectric generator pod that is somehow fitted to a 120mm space cannon for electric ignition of an anti-satellite gun in orbit though.


Somebody has been spending to much time listening to the old Buck Rogers In Space radio programs:-)



Hello Jason,
Its been awhile! I was actually going to buy this as it was in Canada already but passed as it was too odd of an item for my collection, plus I needed money for other items.

When Dave sent me the link for it I looked around online but couldnt find anything and finally showed a friend on mine in the UK. He said he has seen them before, and although this one is not complete and missing almost all the internals and parts that it is used for calibration on the 120mm guns. It had sensors and all types of things on it to measure a variation of things for the gun. I will ask him if he has any more info on it but thats all I know for now. Hope it helps!


Interrupted threads look like breech end if a barrel?


Jason, in the following link you can see a decription and pictures of the item you bought and another one that is attached to a hysteresis synchronous motor ( … Both are made using a 120 mm APDS sabot made by ROF Birtley (see picture below).

I can’t help with its identification but I don’t think that it has anything to do with a calibration device for the 120 mm gun.




Thank you everyone, so much for all your help with this. Fede, awesome link to some better pics of a more complete example like, Rhys mentioned. I am saving those pics. Anyhow, super grateful for everyones feedback and help. Jester, I thought the same thing when I saw the way the threads were modified.