Loading 45-70 shells for a single shot is completely different than loading for a lever. Single shots are much easier, and in my opinion more accurate. I will describe how I do it in my 1885.

Fireform your brass first. When loading to fireform look at the wording on the brass. I use WW brass. I align the first "W"-straight up and down in the chamber. Every time you shoot your ammo, always align the "W" at 12 o'clock in the chamber. This is done so that your casing fits your chamber the same every time.

Now you are ready to start:
1. Trim all brass to the same length.
2. Resize the brass only to the length of the bullet-do not resize the whole case. No need to. It will slip fit right into the chamber. Make sure you remove sizing button from the die.
3. Bell the case ever so slight, just enough to keep from shaving the lead bullet.
4. Use a Sinclair sizing mandrel. Run the case up on to the mandrel to size the inside of the case.
5. Seat the bullet, touching the lands will normally shoot the best. You can push it back a bit off of the lands, but I do not.
6. Use a Redding taper crimp die. Apply an ever so slight taper crimp to the bullet. A heavy crimp is not necessary.
7. This is how I attain my best accuracy from a single shot. You can get alot of firings from a case because you are working the brass very little. And since you fireformed the brass to the chamber there should not be alot of case expansion.

Now all you need to do is cast your own bullets. I like RE 7, and 2400 powder for 45-70's. Tom.