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?