They are for the man who already owns a larger 12 bore and wants a light little carry gun that weight for weight shot load will out perform a 20. In England we tend to fit the bore to the weight of the gun and shot charge. 9/16th. Oz for a 28, 13/16th. Oz. for a 20 and 15/16th.Oz. for a 16. The 2" 12 was a bit of a novelty in the 1930's in an attempt to reinvent the wheel. Ammo is still available from a number of makers but may not be in stock at every gun shop and may need to be ordered. They are just fun little guns for something different to use sometimes. They mount well and seem to pattern better than they should. I certainly like mine even though it only ventures out a couple of times a year when I am moved to use it. Lagopus.....