Note this patent is for the locks, not the bbls. In the Specifications Pieper states, this improvement is "particularly" suited to guns having Three bbls, though parts of it may be applied to guns having One or Two bbls if desired.
I seriously doubt any part of this gun was ever a part of a drilling. The "Pieper Breech" was Piepers name for his "Mono-Block" which he patented Aug 23, 1881 US patent #246,195. A look at this patent will show bbl construction very similar at least to this gun. It must also be remembered that makers (Firearms as well as others) often stamped patent dates & numbers of any patent they onwed upon their products, even though sometimes they were not directly applicable to the model upon which stamped. I suspect they just thought the patents appeared "Impressive".
