You could get brass hulls from a place like Rocky Mountain and load w/o crimp. Just put in OS card, and maybe use waterglass to seal. Not sure where to get data for brass hulls, but they are probably more voluminous than Fiocchi hulls, so data might transfer safely.
http://www.rockymountaincartridge.com/page7.html shows 24 gauge brass cases at 10 for $39.50. These would probably last long if no crimping is done to them. That lets you place the OS card wherever it wants to be, instead of filling to get a crimp.
A look at the loading instructions shows the typical primer that we use for shot shells. It is probably 209 size.
Just so no one comes up with a 3" 24 gauge load. These guys might just make the cases for it.
