This is a Nagant M1895 revolver. I bought one exaclty like it for my son. The revolver is unusual in that the mechanism both turns the cylinder and pushes it forward, to form a sort of gas lock between the chamber and barrel. There is no cylinder gap upon firing.
It is one of the few revolvers you can reasonably suppress. The ammo is unique to the pistol, having a recessed bullet with the brass entirely covering it and a crimp at the top to help form a gas check when firing.
A cheaper substitute, should you wish to shoot are several loadings of the .32 long, which is what my son generally uses.
http://en.wikipedia.org/wiki/Nagant_M1895