https://imgur.com/a/UoyfU2w

Daryl,

I hope that this illustration from the International Ammunition Association website may assist.

There appears to be a thin metal cup in the base that presumably assists with obturation,

There is no provision for extraction, but perhaps the cups were flicked away from the bolt faces before re-loading.

It does not appear to be designed to be pushed through the barrel by the next charge like the base wad of a Westley Richards Monkey-Tail cartridge,