While I do a variation of what's been mentioned to the barrel, I'm surprised that the pan hasn't been focused on more. When I'm hunting I dump the pan charge and clean the pan out every 20 minutes or so. It's incredible how much moisture that powder draws. also, I've seen mentioned that 4f powder does not have a coating whereas 2f & 3f have a water resistant coating. If you're out in damp weather consider using 3f in the pan.
