Today, I want to talk about the 380 ACP, the little cartridge that could. So we're going to take a look at how this big-boned, but unloved, stepchild quietly came into the market and spent nearly 80 years in obscurity before rising to the height of its popularity. Where it was esteemed as the bare minimum for an effective self defense cartridge, before once again falling from favor. And remember: if you think I'm wrong, fight me in the comments; if you can prove I'm wrong, shoot me an email. I'd love to hear from you.

The 38 caliber has a long history, going all the way back to muzzle loading firearms. For a brief rundown of the caliber, and of the 38 ACP, please see our video on the 38 Super. In short, though, the 38 was popularized by Colt and standardized by the US Military.
 
The story of the 380 begins with John Moses Browning, around late 1906, with FN's request for an updated design to replace the .32 caliber Model 1900, which was beginning to look decidedly outdated. The new cartridge's origins, however, are enigmatic. There doesn't appear to be any surviving records that would provide insights into exactly when, or why, the cartridge began development. So far as we know, there was no direct request for the cartridge, and even when released no one really wanted it. It may have been a response to the move away from 32 caliber revolver cartridges in the US or, more likely, an effort to simplify production, as the 9mm was becoming quite popular in Europe, and .38 was immensely popular in the US. Additionally, nearly every Browning design that wasn't a shotgun was available in a .38 caliber. Whatever the reasoning, it appears to be the unique brainchild of John Browning, and was likely begun sometime shortly after his return from Belgium in August 1906. 

This was a very busy time for Browning, between 1905 and 1907 he was heavily involved in development of pistols for the US Military, as well as the new 45 ACP cartridge, and oversaw set up and production of his Autoloading Rifle with Remington. In Belgium with FN, he oversaw setup and production of the M1903 and M1906 pistols, as well as his Autoloading Rifle, and kept FN up-to-date with .45 caliber pistol developments. It is also rumored that FN set up production of Browning's M1895 machine gun during the Russo Japanese War and subsequent conflicts erupting throughout the Balkins and North Africa, which likewise kept Browning involved with Colt's production and development of the gun. When He was wasn't in Belgium, at Colt's, or Remington, or in Court during ongoing patent disputes with Georg Luger, Browning continued development on a new machine gun design, worked on improvements to pump action shotguns, and adapted the Winchester 1895 rifle action to work with a tube magazine. While at home in Ogden, he also regularly organized and participated in trap shooting competitions. It was in the midst of all this that Browning began designing the new pocket pistol for FN, as well as a new cartridge. 

The first surviving records of development come from the Union Metallic Cartridge Company, who began producing samples in January of 1907. 

The UMC cartridge, as made to Browning's specifications, was rimless and straight walled, with the same case length and overall length as the 32 ACP, with a case diameter .005” smaller than the 38 ACP, making it an even .380”. It used 2.7gr Bullseye powder to fire a .355-.356” 95gr jacketed bullet at 850fps. 

Sometime during 1907 or early 1908, case diameter was further reduced, to .375”, before beginning production. 

While the pistol for FN was taking shape in Ogden, the cartridge was also applied to the Colt 1903 Pocket Hammerless, which required modification to the magazine well, a new magazine, new barrel, and modification of the barrel bushing. In 1908 Colt quietly released the cartridge as the 380 Automatic Colt Hammerless along with modified Model 1903 pistols. There were no announcements, no fanfare, the 380 was simply added as another option to existing advertisements. Eventually the Hammerless designation would be dropped and it simply became known as the 380 ACP. Despite the extra machining required and having a separate serial number range, Colt's made no distinction between Pocket Hammerless pistols chambered in 32 and 380, even internally all were known as the Model M. Informally it has come to be known as the Model 1908, along with the 25 ACP Vest Pocket model released the same year. The importance of the Colt Pocket Hammerless can hardly be understated, it was the first to exceed production and sales of the Model 1849 and was the most successful Colt pistol until the M1911. However, the 380 pocket model accounts for less than a quarter of total production.

The new pocket pistol for FN was also completed in 1908, but wouldn't be patented in Belgium until February 1909, or start full-scale production until 1912. Originally titled the New Model Browning, it would later be designated the Model 1910. While not as svelte as the Colt 1903, it was slightly more compact in height and length, and was perfectly suited to the sensibilities of the Art Deco style emerging in Europe. Unlike the Colt which was adapted to the 380, the FN was entirely designed for it, and change of caliber during production required only 1 unique part, the barrel. All other parts, including magazines, could be used interchangeably with both 32 and 380. Exactly when the 380 cartridge, produced by FN as the 9mm Browning Short, was released in Europe is unclear. The designation comes as a distinguishment from the 9mm Browning Long, which was released in 1907. Had Europe embraced the 38 ACP, this would have been a very confusing cartridge line indeed. 

The FN 1910 would be just as influential with European firearm manufacturers as the Model 1900 was, inspiring a new wave of modern pocket pistols. The 9mm Browning Short, however, would initially see the same fate in Europe as the 380 in the US. Where it was offered in pistols that also chambered the 32, the 380 saw only a fraction of total sales. The most notorious use of the Model 1910 in 380, would come in 1914 with the assassination of Austrian Archduke Ferdinand, igniting WWI.

Advancements in powder technology around the 1920s would see the average velocity of 95gr bullets increase to 950fps while still within the 21,000psi limit standardized by SAAMI.

Throughout Europe the 380 would see more widespread acceptance following the war, particularly during the 1930s, becoming a common cartridge among police agencies, and being adopted by several countries for use in an officer's pistol. It was especially popular in the Walther PPK used by German police detectives and intelligence services.

It wasn't until the 1970s that the cartridge would find general acceptance in European civilian use with pistols like the Beretta 84, which were popular options for concealed carry. However, by this time civilian firearm ownership was in a free-fall with ever increasing regulation and disarmament.

In the US, police agencies had never embraced the automatic pistol, preferring the revolver as both service and backup weapon. Caliber, however, had seen a much earlier shift, with 32 caliber cartridges being supplanted by wholesale adoption of 38 Special around 1900. 

Civilian use of automatics was much more widespread, particularly with pocket pistols, and only rose during the 1940s as soldiers returned with an increasing variety of small arms, 380 being rare among these though, as most were 32 caliber. Concealed carry was stigmatized during the 1950s and didn't really become popular again until the 1980s.

As concealed carry in the US transitioned out of it's criminal stigma during the 1970s and 80s, it was ushered along by the rise of competitive sport shooting, which had long been the domain of Military service members and police marksmen. The organizations that grew to meet this new market demand brought with them the sensibilities and traditions of their founders. This, however, presented a built-in dichotomy for the emerging sport. Military doctrine traditionally focused on power, distance, and accuracy (in that order) and was perfectly encapsulated with the use of 45 ACP and 30-06. The influence of policemen likewise brought the tradition of using, at minimum, the 38 Special and 12ga, but was more willing to compromise power for ease of use, to foster accuracy. They also brought an insatiable need to adopt the latest advancements for fear of being out-gunned through complacency. All this was reflected by gun writers of the day, which had similarly grown out of the hunting market to serve the wider audience of sport shooters. The one thing these three disciplines agreed on was that the centuries old use of pocket pistol calibers had no place in modern practical shooting. 

By the late 1980s the Wonder 9s were replacing service pistols, but the 38 Special, snub nose revolver, was still the standard in a backup or concealed carry pistol. By the 1990s, American gun writers were writing off the 380 as an obsolete, never-was, of European preference. That sentiment couldn't have been more wrong. In the late 1990s the polymer frame revolution caused a fundamental shift in firearm design. The pocket pistol, which had been dominated by the blowback action and 32 ACP, gave way to locked-breach 9mm. Likewise, the Vest Pocket Pistol was supplanted by a new market niche, the micro pistol. What was once limited to 22lr and 25 ACP, was now available in 32 and 380 ACP, thanks in part  to the selective use of a locked-breach, adapted to the tiny designs.

As the civilian market embraced the new micro pistols, favoring the sleek 380 over the comparatively bulky 38 Special revolvers, the sporting world begrudgingly compromised and redrew the line of minimum adequacy to include the 380, in very limited use. This has been echoed by modern ballistic testing, though even modern methods are subject to varying interpretation.

With the resurgence of interest in small calibers an increasing number of manufacturers have been producing higher performance cartridges since the late 2010s. Current 380 ACP cartridges now maintain average velocities between 950-1000fps with 90gr bullets in barrels as short as 3”. However, the most common pistols currently produced for the 380 typically have barrels between 2.5-2.75” with an average velocity closer to 900fps. There are even hotter cartridges available though, being able to push 90gr bullets over 1000fps out of 2.5” barrels. Discretion must be used with these, as there is no standard +P pressure for the 380 due to the predominance of blowback designs in which those cartridges are unsuitable and liable to damage. 

The debate over adequate minimum performance still rages on, as the 9mm continues to be chambered in ever smaller designs. The 380, despite it's stigma as a bare minimum and increasing cost, is still holding on, for the same reasons that it was long overshadowed by the 32. In pistols of comparable size, the 380 is more comfortable and controllable than 9mm. While concessions for comfort will likewise continue to be hotly debated, a pistol you regularly practice with will be more effective than a cannon you don't know how to use.