Smith & Wesson did not produce or ship products in serial number order. As a pistol moved through the manufacturing process, at each station no attention was made to which serial number was being worked on, just pick up another frame and do your job. It was the same in shipping. Pull the require pistols to fill the order and only when the invoice was made out were the serial numbers recorded. For example, the invoice that includes my M41 has ten pistols from #12112 to #18968 all shipped on the same day.

The “table” in other posts is only a list of partial serial numbers and the year that particular individual pistol was shipped. It is not a list of starting and ending serial numbers for a year. It was dropped in the 3rd edition of the Standard Catalog of S&W probably because it was too confusing.

I know of a M41 with a higher number than yours that dates to September 1959 and a lower number that dates to April 1962. My best guess is that #21723 shipped from S&W in mid 1961.

Sorry for the long and inconclusive answer but you will have to shell out $100 for a historical letter if you want an accurate answer.

Oh! Welcome to the forum. Hang around and i think you’ll enjoy it here.

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SWCA #3526