Anyone ever hear of a Winchester Model 98?
Before you spend a lot of time in the books, I will tell you that it was Winchester's cannon. They made them from 1903 up into the 1930's, with the last being chrome plated and equipped with rubber tires. The description says it had a 12-inch rolled steel barrel, cylinder bored, with a carriage having two 3 5/8" steel wheels at the front end. It was 10 gauge, and was for blanks, though the company said it would stand up to any 10 gauge black powder load.
The carriage was japanned, the barrel blued, and the breech blackened. Length overall was 17 inches, height 7 1/4 inches, width 7 inches. My source doesn't say how many were made in total, but over ten thousand had been sold by 1915, so there are a fair number out there, and I have seen a couple, usually just sitting on a shelf at a gun shop or, in one case, a restaurant.
I have done some checking, but I don't know the legal status. They are not muzzle loaders, so presumably they would come under the NFA in some way, maybe as an "any other weapon". I can't find that they have been put on the curio and relic list, but maybe I missed it.
Most of my information and the picture are from Harold Williamson's "Winchester, the Gun That Won the West", a company history.
Jim