Why use foil or other modern items in a muzzleloader? Because I can....and like many of you inquisitive folks here, I like to experiment. I already have worked up effective target and hunting loads and materials for every gun that I have. I still like to play and experiment. What better medium with which to experiment than black powder and muzzleloaders?
One idea that you might try with the Aluminum foil, as an aid to producing better shot patterns, is to cut it into strips long enough to fold over the end of a mandrel (or dowel) the inside diameter of the bore of your barrel and wide enough to meet on each side or overlap a wee bit. . Take 2 strips and make a Plus (+) sign with the foil. set the end of the dowel in the center and fold the ends upward around the dowel to make your cup. When shot, the end product looks like flower petals that have opened up.
To load: load your powder charge as normal down the barrel. Place a lubed wad or card into the end of the barrel. Gently push the wad/card into the barrel a couple of inches with your dowel. With your dowel, push the petal cup into the barrel to the wad. Remove the dowel and load your shot charge into the petal foil cup. Place an overshot card over the shot and gently push it down to seat the entire column on the powder.
This procedure has been performed with different materials (e.g. different thicknesses of paper, leather, cloth, wire screens, etc.) with some success and might just work for you with the foil.
I intend to try this method myself when I get around-to-it. I want to try different materials using the PLUS strips and with different types and sizes of shot.
I say: GO FOR IT
@adkmountainken !
DanL