A Canadian fellow who tinkers in gunsmithing came out with a break open, 12 gauge handgun in this video. He incorporated a top rail to mount various optics, and a small forend to hold the monster handgun. The grip appears to be a rugged large frame rubber revolver grip, that must not make any difference in how much the thing must hurt to shoot! According to STG Tactical Canada, there aren’t any other such firearms registered in the handgun category, and so it appears to be the “Most powerful pistol in Canada”.
The practical uses of such a handgun might just be limited to having an awesome 12 gauge pistol, similar to the practical uses of an IWI Desert Eagle. You could probably hunt with it, but if you can hunt with a 12 gauge pistol then you could probably also hunt with a 12 gauge shotgun due to local hunting laws and such. If you needed something that small for some serious wildlife protection, you might be better off with a large caliber revolver. Although, this thing is almost incapable of jamming, compared to a revolver so that might be a factor as well.
Now, shotgun shell chambered handguns aren’t anything new at all, Ithaca came out with a 20 gauge “burglar” double barrel with a pistol grip handgun in the 1920s, there’s a 12 gauge conversion of the 1911 in Thailand among a number of other inventions, and we even blogged about an odd contraption of a handgun that electronically fires 12 gauge shells from a tube while being semi automatic.