Caveat: there is more variance of opinion on this topic than some of the other ones we're covering, but ultimately it comes down to this - no tournaments backed by federations allow them, and they aren't going to change that anytime soon. If you want to spar with a blunt, that's at your own risk (and may violate your insurance policy), but we suggest giving up on trying to convince a tournament organizer. You're just going to piss them off.
- There's less mass in the blade, resulting in milder impact forces
- Feders are designed to flex, especially in the thrust. Blunts are flexible, but typically not to the same degree.
- Feders typically have safer tips, or at least are easier to mount a safe tip onto.
- Feders typically have thicker edges, spreading the impact forces out.
- Feders are historical, even if the modern variants are different. We don't know for sure, but similar modern designs confer benefits to safety, so there's a chance they were used for the same purpose historically as well.