See the book by Colin Greenwood "The Classic British Rook & Rabbit Rifle", Chapter 4 "Needle Fire Rook Rifles". An identical rifle No. 13896 is shown and described on pages 40 to 42. These rifles used needle-fire cartridges of the Dreyse design. They used a quick screw breechplug entering the barrel to both lock the action shut and somwhat seal the breech. About a half turn to the left allows the barrel to drop and open for loading, while turning it to the right not only locks the barrel, but also seats the cartridge and somehow seals the breech. Look at the "bolthandle", checkered on top to be pushed down to tighten the breech. Though this long "bolthandle" was a Rigby peculiar, nearly identical needle fire rook rifles were offered by many British gunmakers. Greenwood concludes: These rifles were made for the British guntrade in Liege, Belgium and may be dated to 1865 - 70.