Maybe you want a gun that offers double capability, like a rifle that also provides the ability to fire shotgun shells.
Gunsmith Horace Warner took a ca. 1884 Winchester Model 1873 rifle chambered in .38-40 and added a 12 gauge shotgun barrel on the top. Through an ingenious connecting rod system, the rifle's hammer can connect to the shotgun's firing pin mounted in the upper breechblock. To maximize the rifle's accuracy, its sights were shifted to the top of the smoothbore barrel.
Quelle: NRA Museum