I picked this fired cADS cartridge up at the UK ECRA Meeting. It is not for my collection, but for a friend who collects any militaria connected to the South African Border War.
I would think that finding out exactly what this was for would be near impossible. However, as it is stamped “M101A1”, it may have a US equivalent.
This is an example of something that is probably quite “rare” but not of much interest to many collectors.
The case head diameter is 30mm, case length 34mm, calibre roughly 27.5mm
Here are a couple of photos: (Sorry for the poor quality photos, they were taken with a phone camera)
Ink stamping ings on case are “CART EJECTOR REL UNIT M101A1 087 A 83”
The headstamp is: “M101A1 A 82 AE”
Thanks for any more info if anyone has any.