He also had a recipe for making up priming powder.
I preferred to stockpile primers when they went on sale. The S==t hasn't hit the fan and if it does, I'm to old and slow to do much about it anymore. The fellow I gave it to, still has it but only uses it to make up percussion caps. The consistencey isn't as important there.
He finds that his ignition powder recipe can be quite variable, depending on where he gets the components.
He puts a bit paraffin over the ignition powder to keep it dry and in place.
He finds that the percussion caps can and do get jostled around in his possibles bag. They can even get damp in there from humidity. That's why the paraffin cover.
He finds that aluminum cans actually make better percussion caps than steel. They go off more readily and don't damage the nipple or hammer.