I shot one, ONE time many years ago in a friends Contender.
Have no idea what load he used, we took it off the shelf from the gunshop/indoor range we used to work at. Now, I was used to full power 44 mag loads in his TC, I used to use it for pig hunting. Nothing prepared me for the 45-70's recoil.
Call me a wimp if some of you want,but Im never going to squeeze that trigger again.
Felt like Mark McGuire took a full swing against my hands.
There is no fun in that sort of pain.
If your going to reload to reduce the umph, why not consider a different caliber ?