As Mr. Roller has said in other posts, L&R uses 52-100 tool steel for their frizzens. They will be hard all the way through. I second Don and suggest you experiment with flint position-- bevel up, bevel down, in, out, etc. I set up my flints to just clear the frizzen with the cock at half-bent and the frizzen closed. Some of my rifles spark best with the bevel down, other like the bevel up. Thickness of the flint may make a difference,too.