step 1 get some .32 short colt brass drill it out and then trim it down as needed(or a HC .22 off set case can be cut down)
step 2 get some .27 cal nail gun blanks uncrimp them and then cut them down to length (a die can be made out of steel tubing and a hacksaw can be used to cut them down they will have to be shorter then the casing so theres room to seat a round ball )
step 3 load with black powder 3f should be used (this will most likely only fill up the blank casing) then seat a round ball in the casing done you got a round and the casing can be reloaded
i have the dimensions if needed