I do know that it is good to have a touchhole liner that is coned out on the inner side of it, with a touchhole not too small. Straight 2F down the barrel is all that you should need, some people use the 4F under their Pyrodex main charge to assist in ignition. Ideally when the barrel is loaded, you should be able to see a kernel of 2F powder waiting for ya in the touchhole, keep the pan filled below the hole with 4F. You don' t want too much powder in the pan behaving like a fuze, you want that fire flaring upwards kissing that kernel of 2F at the touchhole instantly setting off the main charge. Use nothing but sharp edged hand knapped English or German flints for spark every time. Practice with it as often as you can, experiment with charge weights and bullet types, you' ll only improve.