Another excellent book written by the factory Historion Roy Jinks is also shown and I have it as well and I highly suggest it as a Great choice. Here is a direct link to the Factory letter I spoke of and the Excellent reference book the Poster before me mentions that can be ordered from your computer and shipped to your front door. Some models are not as fast selling as others and although a reference book shows serial numbers and list's years when they shipped, it can only be considered a general idea of that model as I have seen some that shipped several years after these books show them to due to a less Popular status or demand for them. It will be a 6-digit number preceded by a 'C' or a 'D'. The serial number of a Model 10 is found on the bottom of the grip frame. The Only True way to know when your gun was shipped from the factory is to apply for a Factory letter. The number you listed for the 10-5 is the assembly number, which is arbitrary and basically meaningless.
I see another responder has Pointed out an excellent source of S&W serial numbers and it will provide many hours of good reading on all the different models they made and make.
