I got these just yesterday from a friend down in the US, I purchased some early M865 sabots from him and he gave me these with them. They where recovered from an AAI Corp building before its demolition. He was EOD for atleast 20 years and had an extensive collection, so I have no reason to believe these are “fake” or homemade. I have pictured them beside a standard 20x102mm dummy round for scale.
The black colored one seems to be made of some lightweight metal, it is very magnetic but lighter than a steel rod of the same size. Could possibly be hollow. It is also a few millimeters longer than the other and has a much longer tapered nose.
Length: 9 1/2"
Fin length: 2"
Body diameter: 1/2"
The other one is much heavier and seems to be made of hardened steel or tungsten. It is ever so slightly magnetic so possibly an alloy, but much heavier than the other. The fin assembly is the same as the other dart, and both are press fit onto the body. The nose of this penetrator is stubbier and not as tapered as the other, and again slightly shorter.
Length: 9 1/4"
Fin length: 2"
Body Diameter: 1/2"
Neither dart have the buttress grooves and are smooth. The fins on both are slightly off center from either other on both. They are very similar to this AAI 30mm experimental APFSDS penetrator with some slight differences however these seem much to big to be 30mm (Picture is of one currently for sale on Gunbroker from seller ORDNANCE.com). I would really like to know what these are from, so if anyone has any ideas, needs more pictures etc please let me know!