This is a replica of a revolver. Not really sure what kind of revolver but, I got some of the dimensions from a page showing the specs for a Ruger SP101 (This was the first thing that popped up on a google search for "snub-nose revolver"). The cylinder spins but there are no other moving parts. This is my second design and if I tried to get carried away with over engineering it, I would have never finished it.