Well a good flint or cut agate (which is what I was using) is the key to a good spark. Besides a hard frizzen of course. If the frizzen is soft you get short hot sparks but it cuts into the frizzen as well. If the frizzen is hard, you get nice long hot sparks.

An agate is not as sharp as a flint, but these I purchased were on sale at Traditions Firearms once, so I bought six or seven of them I think it was. I had real good luck with cut agates in my Trade Rifle as well.

Today this rifle, other then the one misfire/hangfire went off perfect. Very little delay. I still get a kick out of all that smoke they throw.