The short answer is yes.
Case length is about 1.89 and 45-70 is 2.10 so the sizer should work but the seat/crimp may be too long. I had to grind off a bit of the die bottom to get the crimp to work. Obviously you'll need a good crimp with the tube magazine.
The simple test would be to make a few 45-60 dummy rounds with cut off 45-70 cases and see what happens.
The other thing to consider is that after spending the money for the rifle, what's a few more bucks for 45-60 dies?
Just as a side note, the 45-60 is an excellent choice in the '76 and would be my first pick.
