Somewhere in these pages I seem to recall modifying 16 ga to 14 ga by increasing the od of the hull using tape warped to fill the space. Would not paper hulls from Chedite cut to 2.5 inches and wrapped be possible? (probably work with plastic hulls as well). I'd use black powder and 7/8 oz shot. Card and fiber filler. A little pricy but the RMC brass hulls, about 30 would make for practical field use. Like making and using pin fire hulls for those guns.