Both are 209 hammers with tapered firing "pins" (striker). The only differences are the step down shape near the impact end of the top one, and an Allen wrench fitting in the safety end of the bottom one. I'm trying to decide on which to grind the striker flat for caps. Sounds like there were a variety of styles and makes no difference. I thought perhaps the more restricted space created by the step down one might be better at containing the 209 blow back?