Very cool . Funny , only one other person than I have I heard about using arrowheads in a flintlock ! LOL ...if it works , it works ! My powder making is very simple .I hated to use a tumbler , because I didnt want to use modern equipment but it is essential I found out .... I buybthe two ingredients , I make the charcoal ( I'll post pics of it in the paint can , use a clean never used one ) combine them then tumble , 20 hours for a half pound , it can be used after that !! Its too fine for me so i mix it with rubbing alcohol to dough like consistency , rub it through a mess seive on to a cookie sheet, makes it granulated close to 2F , and set in sun to dry ...thats it. There are other steps some use but thats not for me. It works JUST fine. Fast too.