Oh my goodness this does NOT sound prudent at ALL
"an empty (fired that is) 7.62X39 case
(AK OR SKS) is a good powder measure for the .44 BP revolver.
when filled with 3F about 28grs 3F and place a felt atop the powder. then greased slug/ball."
Start with a 9mm then go 38 special-
Heck, I could find a powder measure faster than I could locate a 38 long.