With my Pedersoli Kentucky Rifle, just about every new flint rests against the frizzen in the half-**** position. This ends up creating a gap for powder to escape since the frizzen can't close all the way. What is a good way to shorten the flint so that it doesn't rest against the frizzen? I know I can tap the edge & chip off pieces. But that creates more of a serrated edge instead of a nice, straight edge the way that a fresh flint tends to look. Any tips?