Connecticut Shotgun Manufacturing Company RBL Professional 20-gauge Slug Gun:
It is quite possible that Tony Galazan, who runs CSMC, knows more about fine scatterguns (and in particular, how to make them) than anyone in the U.S. This, however, is not a scattergun; it is a 20-gauge double rifle built for sabot slugs, and is a truly nifty piece of machinery. It's built on a round action, has 24-inch barrels THAT YOU CAN REGULATE YOURSELF FOR YOUR OWN BRAND OF SLUGS, a single trigger, auto ejectors, iron sights, and all sorts of options available including fancy wood, straight or pistol grip, single or double triggers, and assisted opening. The base price is $3,995. You can see it at connecticutshotgun.com.