I have a couple of old brass shotshells in my collection. The used an "overshot" card that usually had the shot size stamped on the card too. The ones I have actually have a very small roll crimp and I understand they used a product called "water glass" to further seal the wads.
You can buy them from MidwayUSA and Cabelas and several other places. Magtech makes one brand that I know of. I have seen them in 12, 20, and .410 gauge for sale.
You can buy them from MidwayUSA and Cabelas and several other places. Magtech makes one brand that I know of. I have seen them in 12, 20, and .410 gauge for sale.