The concave circle with no S&W medallion stocks were used from 1904 to 1910. Assuming the stocks in the picture are original to the gun, that would be the time period in which it was produced. The serial number of the gun should be inscribed on the right hand stock panel. These guns were produced for use with .38 Special cartridges using smokeless powder. As such, it is perfectly acceptable to use standard pressure .38 Special ammunition in them. This further assumes the gun is in good mechanical condition. Keep the loads mild, using either 158 grain lead round nose bullets, or target wadcutter ammo.
Nightlord is correct in stating it is a "Model of 1905". To go a bit further, depending on serial number, it could be a Model of 1905 3rd Model, Model of 1905 1st Change, or Model of 1905 2nd Change. The 6 1/2" barrel was no longer offered on the Model of 1905 3rd Change beginning in 1909. The 1st and 2nd Change serial numbers ranged from 73251 to 146899, and were made from 1906 to 1909. Most 2nd Change models had two dowel pins in the cylinder with two holes in the extractor star to insure proper alignment of the extractor. This information was taken from the "Standard Catalog of Smith & Wesson" 4th edition, by Supica and Nahas. Hope it helps.
