You can put them in the oven at 150 degrees (my wife's oven is a measured 145 degrees on the "Warm" setting) to redistribute the wax and take the swelling out of the hulls. I tried it with 75 once-fired Federal hulls last week, leaving them in the oven for an hour and a half, and it totally removed the swelling. I was surprised that there was little to no odor when doing this.They are pretty nice, I wish they were more waxy though. They swell pretty bad in the duck blind, and I ended up going back to reloading plastic. Maybe the new ones will hold up better.
I wonder if anyone has ever sprayed the exteriors of them with water repellent, like Nikwax, scotchgard, or ReviveX. Never thought of trying that until now.