That’s a post-war .38 M&P long action. You’ll notice that the hammer spur is located near the top of the hammer. The spur is near the center on short action guns. The “Made in U.S.A.” stamp is correct. A lot of people refer to it as a transitional.

The “S” prefix signifies that the gun has a hammer-drop safety. I believe S&W changes to the short action on this model around serial number S99X,XXX

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