[Carriage Hill]

They’re called THV and Monad Bullets:

http://www.quarry.nildram.co.uk/THV.htm

After some searching for a name with which to locate their history, a Google Search returns this:

https://www.google.com/search?client=opera&q=THV+bullets&sourceid=opera&ie=utf-8&oe=utf-8&channel=suggest

[spetznaz]

Much appreciated. I’ve not seen anything like it.

[deks]

Great link! Thanks.