This is where I take the easy way out. I've shot a bundle of that hethen fad stuff. However, ALL four of my Henry rifles have long been set up for 45 Cowboy Special as they are, obviously all .45s
That said, when it comes to smokeless as opposed to BP, I always hesitate to provide load data, as all rifles are slightly different and your results may not be the same as mine. I also trust NO ONE to reload my ammunition. Ever. SO:
Taking the easy way out, i would suggest a browse thru several reloading manuals. Begin at the starting load and work your way up if need arrises. Also, Please Please remember, if your even tempted, fillers can have disastrous effects on many smokeless powders.
Coffinmaker