I would not worry about the pyrodex. I have shot off countless pounds, and had some as long as 6 years. It shot fine. I was told by an old BP shooter to avoid shaking the plastic jar of pyrodex too much. He claimed that the grains will break into smaller grains, and might change the way the gun shoots towards the end when you measure the charge out. Take that info for what it is worth. I don't shake the jar, and all is fine. Keep it dry and don't worry, good shooting....