One thing I forgot to mention in my earlier post. Have someone with a good bore gauge measure the IDs all along the barrel, including the chamber. This will give you a good clue as to whether or not the barrels have been reamed, how long the chamber and forcing cone and chokes are, etc. Expect rather nominal bore diameters if not reamed -- no guarantee but better than flying blind. ALL of the Husqvarna underlever hammer doubles I have seen with over bored barrels got that way by someone reaming them after they left the factory. Also suggest miking the OD of the barrels and comparing it with the IDs. While not a substitute for proper measurements of wall thickness, it is cheap and might tell you that the barrels are the typical thick walled ones of these utility guns.

Niklas