A guy posted this question under the Rules thread above so I moved his question down here to give him an answer.
"Haowdy(that's Ga for hello) Gotta flinter, pedersoli, a nice Penn, been smokin some (powder,black) and been told y gotta keep yer flints SHARP. So how often should one knapp their flints, been told every shot. Btw I've got english flints..."
Good quality flints only need to knapped every 25 shots or so and possibly up to once every 100 shots if your lock geometry is just right. Some locks are flint bashers, on these locks the flint hits the frizzen straight on instead of striking it at an scraping angle.
If you get a miss fire and the pan doesn't flash it is time to knap the flint.
The easiest way to sharpen a flint is to put your finger under sharp edge, tight against the flint and very lightly tap the edge all the way across with just about anything metallic.
There are more styles of knapping tools than you can count, everyone has his own take upon the subject. Some are for use as I mentioned, some are little drifts that you put against the flint and tap with another object.
Here are some of the things people use, some quite ingenious.
https://americanlongrifles.org/forum/index.php?topic=58745.0I use a flint flaker like one would work arrowheads with. Sometimes I hold it in two hands and get agressive, sometimes I put the copper tip against the flint and tap the antler handle with my round head ball starter.