The Boss & Co O/U Sidelock in .410 bore is the rarest and most extraordinary of all Boss productions in any configuration. Only a handful of .410-bore Boss O/U guns exist; each was produced as part of a matched set commissioned at extraordinary expense. The .410 Boss O/U combines the world's first successful O/U sidelock design with the smallest practical sporting bore, resulting in a gun that weighs under 5 pounds and handles with improbable elegance. Type: Shotgun Action: O/U Caliber: .410 Bore Capacity: 2 Year introduced: 2010, United Kingdom Weight: 52 oz Overall length: 42" Status: Active Intended use: Upland / Sporting