With its easy-to-switch barrel system, Mossberg's SSi-One brings modern technology to the world of traditional-style hunting. The SSi-One is a lever-opening break-action single shot firearm that utilizes a unique interchangeable barrel/caliber/gauge system. Its sophisticated features and design give it the extremely high accuracy and reliability that the most experienced veterans of the field demand, yet it is simple enough for beginners to operate. Similar in many ways to the Ruger No. 1 or the Thompson/Center Encore, the SSi-One holds zero like no other and is built on a sleek, simple walnut stock that serious hunters appreciate. In addition to an integral hammer block and an automatic safety, the SSi-One employs a mechanical block that keeps the action from closing unless cocked, protecting the integrity of the internal magazine. This combo includes a 24-inch .223 Remington rifle barrel and a matching 24-inch, 12-gauge shotgun barrel with an extra-full choke tube. Its wood, metal, and bore are all in excellent condition.