Well, unfortunately that Volcanic pistol is a total fake. I bought it a couple years ago from a company that makes non-firing replicas (movie guns/stage props). That action does work on it, working the lever raises the cart. carrier block, cocks the hammer. It loads like a Henery rifle.
There's a fellow on You tube shooting on of those things, If I recall he built
this one, was shooting .22's in it.
There's a few originals still around, they come up for sale occasionaly on those gun auctions. As far as I can tell, no company makes a replica.