So, what exactly is the cause of the rise of the 380?
This time around? The rise in the number of people carrying concealed.
The cartridge was introduced by FN about a century ago. At that time the most popular small handgun cartridge in the country was the .32 S&W. The introduction of self-loading pistols resulted a lot of sales for the .32 ACP and .380 ACP.
Believe it or not, police departments in this country often chose .32 S&W Long revolvers at the time. I have one my grandfather got from a policeman who was not at all pleased with its effectiveness.
In Europe, 7.65 automatics (.32 ACP) were widely used by the police. The French military even used them.
The .380 is more effective than the .32. The Beretta Model 1934 in .380 was a standard Italian military side-arm.
Colt autos in both .32 and .380 were issued to U. S. general officers until about thirty years ago.
I think the primary appeal was and probably is the flatness of the little auto pistols.
They're not for me. If I were to choose to carry one, I'd be darn sure to use the most effective personal defense cartridges available.
Of course, you won't see a French soldier or U. S. General carrying a 7.65MM pistol any more these days, either. Things have changed. Could be that the bad guys are worse today.
I've often wondered what might have happened had the French or Italians (or even the Russians, who used small caliber sidearms) had encountered the Moro tribesmen who gave our troops so much trouble in the Philippines. Perhaps nothing. The U. S. adopted the .45 ACP after that, but to my knowledge, only Norway and Argentina followed suit.