RAEDWALD
40 Cal.
Probably been posted before but this is an old paper on the subject which goes into much detail of how the professional knappers made gunflints and is well illustrated. Handy for anyone who wants to give it a go.
https://books.googleusercontent.com...02xgTA5Yzo8BbixsJdQ8hrwYhBs-XTUbgxZufQHBPQKGg
https://books.googleusercontent.com...02xgTA5Yzo8BbixsJdQ8hrwYhBs-XTUbgxZufQHBPQKGg