I started experimenting with overloading 9mm pistols as soon as I started reloading in 2000.
I only started getting serious about testing the 380 with in the last year, but I did get 357 mag performance out of a 380 in Sept 2003 [1187 fps 158 gr], but that was just a raw datum, and not the falsifiable science I am trying to assemble now.
The People Magazine version of what I would say about the 380 vs the 9mm is:
1) 9mm pistols almost all have thick chamber walls, heavy slides, room for good recoil springs, and case support to .19" or less [9mm case webs are .16"]. This makes for a robust pistol that can take double loads of Power Pistol and kick like a mule.
2) 380 pistols can have thick or thin chamber walls, heavy or lite slide, big or small recoil spring volume, and case support from .17" to .29" with 380 brass having a case web .175" thick. This makes pistols that can barely tolerate 380 +P to pistols with hot handloads that can beat the best factory 357 mag ammo with the same short barrel lengths.
What does it all mean?
With the wide variation in 380s, the pistol may be able to handle just wimpy or really hot. The tiny one that fits in your shirt pocket is likely the wimpy kind.
The word 'forum" does not mean "not criticizing books."
"Ad hominem fallacy" is not the same as point by point criticism of books. If you bought the book, and believe it all, it may FEEL like an ad hominem attack, but you might strive to accept other points of view may exist.
Are we a nation of competing ideas, or a nation of forced conformity of thought?