Lodge2004 wrote:The Standard Catalog of Smith & Wesson, Second Edition, is not as clear to me on that model/serial number. I am NOT an expert in any way. Just so happen to like S&W handguns and own a few.
D524xxx falls in to the following date/serial number range: 1973-74 - D510001-D659901, but it also shows those serial numbers as belonging to models 10, 12, 13, 14, 45.
The model 64, 65 serial numbers don't start until 1976-77. It has a 1D prefix and your number would fall in the following date/serial number range: 1979-80 - 1D45001-1D99999.
Since the 64 started being produced in 1970, perhaps they used the D prefix the first couple of years? The original 64 had a tapered 4" barrel. The 64-1 (circa 1973), and I believe later models as well, swithced to the 4" heavy barrel.

Thank you. Mine has the 4" tapered barrel so I presume it's an earlier model? It appears that this gun is still available, but as you say, with the heavy barrel. My gun has ".38 S&W Special Cartridge" stamped on the barrel without any mention of +P. Whatever date it is, It is pretty and it is a shooter. Thanks again.