The Holland and Holland "Paradox" and the Westley Richards "Explora" and "Fauneta" are the preeminent ball and shotguns utilizing rifled chokes. A number of other makers had their own versions with different methods of stabilizing the projectile while maintaining good shot patterning.Barreled from 28 to 8 gauge with the 12 being most common. Two Hollands just sold at the Holt's Auction. Prices range from about 5K to 50K US.