I'm trying to ID the model of this S&W 5-shot flat latch with 4" barrel. Its chambered in 38 S&W. I thought flat latches were only on Model 36 revolvers but the 36 didn't come with 4" barrel so here I am....
Guy nailed it. More specifically a “.38 S&W Regulation Police Model of 1953 NEW I Frame”. A 3 screw version. Built after 1955.
The J frames had flat latches from their beginning in 1950 until 1966. And the I frames from about 1952 until about 1961 when they were all turned into J frames.