I have read posts from others, warning of the absorption properties of Clean Shot and American Pioneer Powder. They are also suspecting that Pinnacle will fall into this group. That's what I find so confusing. Wisconsin can be a humid place for the most part in the warmer weather, nothing unbearable mind you. Of course in winter, we have lots of rain, sleet, or snow. That's why I am surprised I never had a problem with Clean Shot or Pinnacle sucking up moisture. I had Clean Shot laying around the house in a large plastic ketchup bottle (a poor man's cheap and free powder horn) for almost six years. The powder shot as good from the first to the very last shot. At no time did I take special precautions to keep it moisture free. The same with the two pounds of Pinnacle I shot last winter. It layed around in the containers it came in with a plastic pour spout on the top until it was used up, in the gun room on a wooden shelf. No other precautions were taken with the Pinnacle also. I have yet to shoot American Pioneer Powder, but fully intend to get a couple pounds of it and more Pinnacle and look forward to shooting it. I guess I will see if I have problems with the powder or not.