It looks like those 8mm shells are crimped over the shot. Early on in this discussion the idea of using a die intended for crimping blanks came up… I have to wonder though, how many times that brass case will take a crimp before failing. With the high cost of cases, this is a consideration!
OTOH, with the Woke movement to Green Practices, those plastic straws are disappearing too. I guess if we’re going to make out own shot loads for revolvers we’ll have to pay to play, however we do it.
Froggie