Not 45-70 but I have shot my 1895 Marlin guide gun in .450 Marlin with 400 gr jacketed at 2000fps.
I loaded 5, shot 4 and decided that the last one didn’t need to be fired.
I won’t be doing that again.
And I don’t consider myself recoil sensitive.
I do have a 45-70 barrel for my Contender handgun and my favorite load through that so far is 70 grains of black substitute behind a Lee 405 grain rnfp. It is a pleasure to shoot and accurate.