dave cash,
Your DEFENDER 38 is one of a series of .38 S&W (will also accept the British .380-200 cartridge) 5 shot, typically 4" flat sided, round bottom barrel (a very few are known with 6"), blue finish, DA/SA, auto ejecting, hinged frame revolvers with the "RICE" (bird's head shaped grip) frames. This series was derived from the large frame, .22 cal. SPORTSMAN series.
The earliest examples seem to derive from the 1938-'39 period, and are either "un-named" or will have DEFENDER stamped into the left side of the barrel. These will have the SPORTSMAN frame but non-adjustable front and rear sights (different from the SPORTSMAN). By 1940, the design of the DEFENDED 38 seems to have "jelled" into the form that the rest of the series (which ran at least into the 1946 period) will have and was catalogued as the MODEL 25.
This war-time series will have front adjustable for height sight blade, usually seen with a "gold" bead inset into the blade; rear windage adjustable sight and the ones after 1940 will have a trigger guard without the second finger rest extension. All these will have a pivoting firing pin slotted and pinned to the hammer nose. The 1940 (letter code 'A' and, possibly, the 1941 (letter code 'B') models will be equipped with checkered walnut monogrips. During the war years the monogrip was changed to brown or black Nylon platic material.
The DEFENDERS can be broken down into several variations depending upon outward configuration. The variations can be pretty complicated and I would need to see a pic of your gun to tell for sure, but most likely, from the serial number (these were all numbered in their own range), will be a 3rd Variation and made in early 1943. I have examples of the entire known series, including one that is NIB and came with a factory inspection slip dated May 8, 1944 - this one is serial number 13533. The total production number is not known, but it doesn't appear to have exceeded 20,000 units, at least from the serial number range known at this time.
H&R period advertising suggests that these guns were suitable for Civil Defense, Bank Guard, Security Guard, Plant Guard and auxilliary police use. My experience with the dozen or so that I own or have owned is that they are sturdy and well built, with "good" fit and 'war-time' finish.
After 1946, H&R made some adjustments to the design and eventually came up with a model that was called the 925 but had the 1880's style manual ejecting system, and a 4" or 6" barrel. This series was further changed and became the DEFENDER MODEL 925 2nd Model as a standard around 1964 and was offered with a 4" or a 2.5" barrel with modified, shorter grip frame. Some have been noted chambered in .22lr. The Model 926 came out in 1968 and this model was always equipped with a 4" barrel and chambered in .22lr or .38 S&W. At some point after that, the M925 was made exclusively in .38 S&W with the 2.5" barrel and rounded butt - while the M926 was made exlusively with a 4" barrel and both chamberings. Both these models, remember, are MANUAL ejecting - but retained the frame and barrel assembly of the SPORTSMAN with adjustable front and rear sights. After 1973 both models were offered with the then new H&R version of a "transfer bar/safety ignition system."
Here's some pics to go along with the narrative:
View attachment 152045
Discregard the following thumbnail attachment - I got it in here, but can't seem to get it out - it's not relevant to the DEFENDERS.