Original piece; Probably a copy Colt 4½" Octagon barrel revolver or similar
.
Barrel sleeved to take .22" Air Gun Pellets.
The cylinder takes brass "bullet cases" which are in 2 pieces. The larger piece is the cartridge case which has a pressure valve and a firing button in the base where the primer would be. The case is primed with air using a HP bicycle pump which can be screwed onto the neck.
The bullet part can be loaded with a .22" pellet and then screwed onto the case neck where the pump has been attached. The 'round' is then loaded to the cylinder as a normal round would be.
Then the hammer is released the air pressure in the case is released and propels the pellet out of the barrel.
Not a great range but different.
I hope to be able to post pictures in the near future

