I have used my fathers old 30-06 310 tool to load for the 30/40 in the past. It worked very well. My father used a sawed off case with a copper wire soldered to it for a powder measure then dumped the powder onto a Pacific scale pan to finalize. It was a good system and I did the same for another reduced load.
I did lap out the neck sizing die so as to not over work the brass and made a couple of expander dies for different styles of bullets. The threads are odd ball but not that difficult to duplicate.