45-70, i haven`t modified the crimp die so there is no crimp on that blank if that`s what you referring too.
No, that was not what I was referring too.
I was just curious as to what dies you had selected. 45-70 will work as a starting point. I used them for a while, years ago when I started trying to reload for an old original 1876. However, you will get better shooting results with the proper dies. The 45-60 actually has just a bit of a bottle neck to it. I use C&H 45-60 dies, but Lee also makes a good, inexpensive set.
My Uberti 45-60 works well with the shortened 45-70 brass, and requires no rim thinning. I rough-cut the brass with a dremel tool and then fiinish it to length (1.89) with a Lyman case trimer. I use bullet #457191 (300 grain) which is available from Bufffalo Arms, and it very close to the original bullet used in the factory load. The bullet must be crimped above the crimp grove in order to get the proper length for the action (2.25). I use a Lee Factory Crimp die when loading this caliber with smokeless. You have to request it from Lee, as I don't believe that show it on their website.