Seems to me just use 45/70 load data in it...it'll be lower pressure, so I don't see what would go wrong..
as long as you avoid slower powders in small charges....

444 Marlin load data would also be usable.

did some loads like that for an older guy about 10 plus years ago...he enjoyed them...

he has sadly since passed...he was in his early 80s at the time... just couldn't reload anymore..

"Minus the killings, Washington has one of the lowest crime rates in the Country" Marion Barry, Mayor of Wash DC

“Owning guns is not a right. If it were a right, it would be in the Constitution.” ~Alexandria Ocasio Cortez