What you're looking for is the LeMat Pistol, designed in the mid 19thC. Very popular cavalry weapon during the Civil War. It was a big-bore six-shooter with a 16-gauge barrel underneath, looking something like the idea of the 40MM tube under an M16.
The LeMat is currently being manufactured in Italy and the US by a couple of those companies that work the Cowboy Shooters and collectors markets. Apparently works great!
www.civilwar.si.edu/weapons_lemat.html
Should be enough to cause immediate and severe local sanitation problems amongst your neighborhood perps.
IMNSVHO, not a good candidate for IWB concealed carry, unless you weigh about 375 and wear muumuu's under a parka.
Way cool!!!
Some brainy gunsmith needs to take that design and upgrade it with modern materials, methods and such. Get the weight down, etc.
Can you imagine what a load of buckshot would do to a perp at close range? Hell, with that, it’s practically impossible to miss.