I made this out of two 21st Century Ithaca shotguns. The Ithaca shotguns eject their shells out the bottom and do not have side port ejection holes.
I shaved down one side on each gun and glued them together. I finally got around to getting it painted. It is a short stubby little thing, so I imagine it would really kick. But hey, if your in a jam do you really care?
Her are some WIP pics.