Anyone made up brass for this one yet. Or do you have to form it?

Go to 6mmbr.com
I've read info on the Dasher there.

I don't have any experience with the 6Dasher or the 6BR, but according to Ammoguide the Dasher can be fire formed from the 6BR ammo. The Dasher looks like a cool cartridge. An AG info contributor says he gets 3300 ft/sec with a 105 grain Berger bullet from that fat little case. Very respectable in my opinion.