The front sight is a "Gilbert's Two Eyed Sight" to prevent cross-firing
Greener's "The Gun and Its Development", 1888
https://books.google.com/books?id=LAsAAAAAQAAJ&pg=PA531&lpg



Modern Meadow Industries Sight-Blinder Crossfire-Reducer



I think it is unlikely that the breech device was attached for wing or inanimate target shooting.