Probably the most produced and most underlooked revolvers in the S&W line are the 38 caliber K frames. The model 19s and 66s as well as the big N frames get a lot of attention as do the newer 686 series but there are more 38 caliber K frames out there than any of the others. The first 38 M&P Hand Ejectors were produced in 1899. There have been changes, but they are still making them today. Here are my Model of 1905, 3rd change from 1911, Pre model 10 from 1955 and my 1983 model 64, representing 72 years of 38 caliber K frame production