The New 251 Falcon from Gary...
25-20 brass is as rare as hen's teeth these days. So, Gary and I discussed forming from different cases.
Believe the Hornady 218 Bee may be the easiest, but time will tell.
I necked up some well used 218 Mashburn Bee cases in 251 Falcon dies to get an idea of what we can expect. It worked just fine.
218 Mashburn, 25-20, 251 Falcon and 256 Win Mag