I take it the cartridge shells are the barrel in themselves, it does not look to have a .177 rifled barrel inserted through the 6" barrel of the revolver itself where in any case the cylinder gap would negate its worth?
A short cylinder or barrel is all that's required for a gas pistol where a sharp small burst of gas sends the light BB or pellet on its way.
Might have to invest in one of these for old times sake seeing as I no longer own the real thing, damn what was I thinking.

I do have one of those pump up Crosman American Classic air pistols in .177 cal and use slightly heavier lead BBs instead of steel BBs or pellets. This pistol is superbly accurate and hits real hard, easily penetrating steel cans from side to side without pumping to maximum.