I was wrong....You DO have a Colt Army Special. Sorry.
Open the cylinder and look for the serial number on the frame, just below the barrel, and on the inside of the crane the cylinder rides on.
With the serial number, we can give you the year it was made.
History-wise, the Army Special was made from 1908 to 1927.
Since the Army didn't buy the gun, in 1927 Colt changed the name to the "Official Police" and that's just what it became...THE official Police revolver for a great many departments.
In later years the same frame and action design was used to make famous guns like the Officer's Models, the old model Trooper, and the Colt Python.
The design has changed so little since, most parts will interchange between a 1908 Army Special and a brand new Colt Python.
The Army Special was available in .32-20, various obsolete .38 caliber cartridges, the .38 Special, and the obsolete .41 Colt.
Barrel lengths were 4", 4 1/2", 5", and 6".
From 1908 to 1923 the factory standard grips were black hard "Gutta Percha" rubber with moulded-in checkering.
From 1923 to end of production in 1927, checkered walnut with silver Colt medallions was standard.