Roller

[Kurt]

Bill.
Is this a .44-70 Maynard chamber? That is a great caliber if it is.
If that chamber has a tight case neck using the chamber reamer for a sizing die is not ideal for use on new unfired brass even if it is annealed because the brass will spring back a little making chambering hard as well as extracting the fired cases once you get the round chambered for a few loadings. I went through this with one of my rifles using a chamber reamer for the sizing die. When I order a die for a tight chamber I also get a matching reamer with a smaller diameter made so this problem does not happen. But once the brass has been fired a few times the chamber reamer die will work great.
One thing in your favor is your roller it will came a round in but you might need your rod to get the fired case back out for a couple shots.
Kurt