Kurt250
If you want to modify an 1860 Henry to shoot 44 Russian this article may be of interest to you.
http://www.9thnycavalry.webeditor.com/henry_article.htmlIf you want to shoot live then you might be interested in knowing that the .44 Russian shell with a bullet is about the same size as a .44Mag. without the bullet. So the modification to the Henry to shoot blanks made from .44Mag. brass should allow you to cycle and chamber a full sized .44 Russian with the bullet.
I don’t know how much accuracy you will get out of the gun because the bullet has to jump from the case to the forcing cone if you use the .44 Russian in a gun designed for 44-40, but it works great for blanks.
Terry