That +P+ stuff was a "work-around" load. At the time the word Magnum was a dirty word in the media and was bad press. The ammo companies started making "light Magnum" ammo and calling it .38 Special just to keep the media happy while supplying good ammo the the LE agencies to keep the officers safer. Like said above, it was mostly used in medium frame .38 Special or .357 Magnum revolvers.

For the most part Speer is doing the same thing but in reverse. They are making a 1000 fps "short barrel" round and calling it Magnum. @1000 fps it's hardly a full Magnum round but it makes the people who buy those 12oz S&W J frames happy because are shooting a Magnum round from their $900 revolver. In reality those short barrel Magnum and .38 Special +P+ rounds are identical. It's all in the words you use...

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