FTF near Camby / downtown Indy
From info stamped on the gun and online research...
Hopkins & Allen model Ranger
seven-shot 22 Long caliber single action revolver manufactured between 1871 - 1879.
This gun is only slightly larger than the NAA mini revolvers.
Rifling is visible in the barrel which is pretty clean considering the age. The hammer cocks back nicely and the firing pin protrudes prominately through the aperture. Although I haven't fired it, I believe it is capable except for the one issue it has. The cylinder stop has worn to the point that the cylinder spins free and will not "lock up". I'm not sure the image captures it but I tried. I believe someone with the knowledge and equipment could manufacture one and replace it (there is a small pin that can be punched out to remove it).