this is what im using for my cast bullet loads when using pistol powder.. people have often asked the question of how to use small pistol primers in their rifle cartridges and all of them got back it cannot be done because they are smaller and thinner.. i have the solution.. i turned these out on my punch press with a set of drawing dies a little while back, they are adapter cups for the small pistol primers.. i can also make primer cups for making primers from scratch with this setup.
but these work great for most cast bullet loads. i have actually tried a few with full power loads and they held up but flattened out pretty good. i still would not recommend doing this with the full power loads and only the low pressure cast..also if you have extreme head space id not do it either. im not sure how most rifles would fair with the extra thickness, a mauser seems to have no problems as the firing pin comes down like the hammer of doom.
i made them out of 0.015 thick aluminum from a cake pan i got from scrap aluminum bin. yes that is a cake pan as in baking a cake.. i have shot a few hundred cast rounds with this setup and have not had one problem when using standard cast loads with unique powder..
also you can actually on some large rifle primers drop the anvil out and pop the dent out of the used cup and drop a small rifle primer right in and shoot that way.. but as i said, it takes a serious firing pin blow to set it off that way and a mauser has no problems..