Well, they ain’t revolvers, this should probably be in the Reloading section to get due attention, but...
3031, 4198, and Varget. If I can’t do what needs to be done in .45-70 with those 3, I’m probably trying to do something which shouldn’t be done. Varget will be dirty with such light bullets, and since you’re single feeding, you won’t need to crimp, so it’d be even worse. But 3031 should suit your needs just fine.