https://www.canadaammo.com/product/d...rifle-primers/
I haven't used the Berdan primers from these guys but do use the boxer types. All Russian made.I have been using TulAmmo KV-7 large rifle berdan primers bought at a gunshow. They work great in the gp 11 brass and old 8mm too. I do understand that there is diferent sizes of berdan primers. This from an older web site.
http://www.dave-cushman.net/shot/ber...imensions.html