I always used to use fired brass for a snap cap. But I figured I'd get some real ones for my CPO Sig. So I bought a package of six Traditions brand (the Fiddler on the Roofs in me likes that) at Parro's nice new store in Waterbury for a pistol that allegedly doesn't need them and had at it. I think it's good for the manual of arms part of learning a new gun. Now there is a nice crater in the brass "primer" and the extractor is beating up the base of the cap. My question is: When has the snap cap had the radish and needs to be replaced?