Attachment 121184 Responding to the bad press from the Philippines, Smith and Wesson lengthened the Army's service cartridge by a small amount, upped the bullet weight and powder charge a little bit to bring the .38 Special to the market in its Military & Police revolver. That's why the .38 Smith and Wesson Special is a longer version of Colt's cartridge rather than a longer version of its own proprietary .38 S&W cartridge. The idea was to promote the fact that both the US Service cartridge (aka .38 Long Colt) and the new .38 S&W Special could be fired in the new Military & Police revolver. Early ones are even marked that way.
Attachment 121184 Attachment 121183