Steve to deprime Berdan type primers you need a special tool such as an old German one from EBAY or similar site, or a modern American one as sold by Huntington and similar suppliers, or a homemade one similar to a toothpick with a chisel point. Some of us old guys still load old stocks of Berdan primed cases, but Berdan primers are becoming harder to find. I have had some of mine for 53 years and they were old then. Buy every noncorrosive (RWS) Berdan primer you can find "on speculation"'.
Mike