I used to de prime berdan primed martini cases with a short piece of 3/64 piano wire soft soldered into a bit of 1/4 mild steel rod. I do not know if you can still get berdan primers. I would also drill the flash holes out with the 3/64 drill. I was only loading these cases with black powder. It is tedious but can be done. I would also be casting in pure lead if your rifle has a choked bore, at least to start with anyways/