actually the (sucks water out of the air) is very untrue. Ive had rifles loaded for a week and 2 weeks and both shot their original POI. Now if the powder does get wet, it basically will turn into a hard "Pellet" I had it happen while testing a rusted barrel, the nipple threads were letting condensation get to the powder in the bolster and it was a solid block. Fired off perfectly. Some teflon tape on the threads sealed it off from moisture after seeing that, i do it on all of my sidelocks. Consistent seating pressure is the most important thing to do while shooting the powder. You have to seat the bullet until you feel the powder compress, then its ready. It likes hard seating.