I once helped a beginning trapshooter and reloader who was experiencing a lot of bloopers during a Saturday winter league shoot. We loaded 10 boxes of my recipe on my loader for the next day's shoot. But he still had bloopers so I asked him where he stored his shells and learned that he kept them in his car's trunk. I did too but my car was parked in a heated garage. I told him to take them indoors and the next weekend, they shot just fine.
Ed