Smith & Wesson 638 

S&W had developed the .38 S&W Special in 1902, and in 1949, company president Carl Hellstrom requested a new small-frame revolver to fire the more powerful cartridge. The result was the famous M36, or Chiefs Special. It was offered in square- and round-butt models, as well as an Airweight version with an aluminum frame. But the exposed hammer snagged on clothing and was less than optimum for pocket carry.

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Thus, in response to requests from law enforcement agencies, S&W modified the J-frame by adding a small exposed tab to permit cocking the hammer and single-action shooting, if desired. S&W called this design the “concealed” hammer, as opposed to the truly enclosed hammer of the Centennial models of 1952.

The first of two new J-frames was the M38 Bodyguard Airweight (aluminum frame), which debuted in 1955. A steel-frame version (M49) was added in 1959.

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