Sizing the cartridge case is not a problem both the initial die and a Case Forming Die the gun came with resize the 45-70 government case to the correct dimensions in terms of near matching up to the chamber cast I did, matching up to the fire formed cases, and to the spec diagrams I have.

While the expander plug seems oversized, in the end that is an easy work around. I can always hone it down to the right size once I am sure what that is. The problem is the final bullet tension is loose. This is either due to me using too small a bullet or the dies not being made tight enough.

Once I have had an independent and qualified verification of the bore slugs I can move forward.

The current die set I am using is a CH4D set and when I put the case with the 0.423/0.424 bullet into it I get no resistance at all. It appears that both the case and the bullet is smaller than the die. Only the bullet seating cone makes contact with the top of the bullet. I get no resistance from the die at all.

If it turns out to be the die I believe my best course is to send the case with the correct bullet to someone to have them make a die that is correct.

I have to still get a trim die from CH4D so I may have them make me a custom crimp die or something of that sort.