Zeke
AA 5744 is the only smokeless powder that I use, because of my 45-90 loadings. Getting into the fall/winter months after the snow flys the outdoor range areas are sometimes not accessable. I have an indoor range I go to that I'm a member of, so using BP is not desirable.
AA 5744 is most friendly to use and work loads up with. You can find your data in either the standard or obsolete cartridge area. I'm currently working on some JSP loading for this cartridge. You will notice that in their data for the 45-90, they do not list any bullet loads for JSP's
Load Data RifleI have since spoken with the company, and have gotten a starting point for both the 300-gr, 350-gr and 405-gr JSP bullets. They list these bullets for the 45-70 and the 45-120 loadings, but not for 45-90, 45-100 or 45-110. I just had to find out why not?
I know your question was for the 45-70, but I just thought I would add this bit of information here.
Have a great one and good luck with your 45-70 loadings.