Today I want to talk about one of my favorite pistol cartridges, the much misunderstood, 38 Super. 
Like all good stories, this one starts at the beginning, all the way at the beginning. So let's go down the rabbit hole with more than anyone has wanted to learn about this Super 38 Automatic cartridge. 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 first point of confusion for many comes from the name, why is it called 38 when it uses a .355-.357” bullet? Most people will say it's because of the size of the case, but that's not entirely accurate, and it's a long story in itself.

In the early 1800s the most advanced handguns fired from a revolving cylinder using a cap-and-ball system. Powder and ball in one end, cap on the other. One of the most popular revolvers was a .36 caliber Colt. .36 caliber refers to the inner diameter of the barrel, or bore size. is another point of modern confusion. Before we

.360” at the lands and .375” at the grooves. The chambers of the revolvers were generally .377” diameter, and the round balls made for the gun were typically .380”. All these varying measurements were to ensure a proper gas seal as the lead ball traveled through the gun. The .380” ball would first be forced into the .377” chamber over a charge of black powder. When fired the now .377” mostly-round ball would be squeezed further as it left the cylinder and was propelled through the forcing cone and rifling of the barrel. Because of the swagging done to the bullet a lubricant mixture of wax and grease, which was essential in muzzle loaders, was relatively optional and typically applied to the chamber over the bullets. While this grease did act to lubricate the bore and soften black powder residue, its primary function was to stop hot gasses from igniting the powder in the other chambers of the cylinder.

Around the mid 1800s the first commercially successful metallic pistol cartridges were being applied to revolvers that had been converted from cap-and-ball. The first were rim-fired and later center-fire. The conversion consisted, among other things, of drilling the cylinder through from end to end. Due to the straight-walled chambers, cartridges were made with cases and bullets of the same diameter, the base of bullets having a”heel” to fit within the case mouth. For .36 caliber revolvers that diameter was .375”, which was just big enough to fill the barrel bore and just small enough to smoothly fit into the .377” chamber. Because the bullet was no longer being swagged down as much it required a ring of grease to help form a complete gas seal while traveling through the barrel. This was placed in a groove just in front of the widest section of the bullet. Manufactures rounded up the .375 diameter in advertising the new cartridges and called them “38”. The practice of naming things after the nominal groove diameter became standard practice within the US at this time, which is why many cartridge names adopted during this time do not accurately represent current bullet diameters.

Having a heel and lube on the outside of the bullet caused issues, as anyone who's used a 22lr has experienced, so things were eventually changed as manufactures started making new revolvers intended for the new style cartridges. Smith & Wesson and Colt, the two industry leaders of the time, came up with the same solution to improve their 38 cartridges, but used slightly different dimensions to ensure their guns only worked with their ammunition (at least at first, sort-of). Case diameter was increased, Smith & Wesson to .385” and Colt's to .379. Bullets were made with a smaller, consistent diameter, .361” for Smith & Wesson, and .357” for Colt. Cases were lengthened slightly to allow the lube groove to sit within the case, and cartridges were named 38 Long to denote the change. Both companies reduced their barrel bore to a grove diameter of .361”-.363” and used a hollow base to improve bullet expansion and accuracy. In practice, Colt's tolerances were generally so loose that cartridges and pistols of either manufacturer could be used interchangeably. Due to the issues caused by Colt's wider tolerances they would further reduce their barrel bore to .357”. In an effort to maintain military contracts, Smith & Wesson would follow suit and also standardize their cartridges and barrels to Colt's .379”/.357” dimensions as well. With the smaller bore, hollow base bullets were no longer used and accuracy improved with the slightly heavier solid bullets. After nearly 40 years of advertising the renamed 36 caliber revolvers and cartridges as the bigger, better 38 caliber, there was no way anyone was going to admit their guns and bullets had actually gotten smaller, so the name “38 caliber” stuck, and is still used to this day.

But what does all that revolver nonsense have to do with the 38 Super Automatic?

Well, firearms development stepped into the modern era around 1890 when the centerfire brass case and inside lubricated bullets were combined with smokeless powder. It took another couple years for reliable powder and primer combinations to be developed, but during that time the first successful work was done with auto-loading pistols. While the first commercially and martially viable designs were being developed in Europe, in the back woods of the US territories an inventor was already a decade into a career laying the foundation of modern small arms design.

In 1894, while John Moses Browning was developing at least two rifles, two shotguns, a machine gun, and experimenting with automatic rifles he found the time to apply the gas-operated toggle design of his machine gun to a handgun. But turning a design that required a tripod into a gun that could easily be held in one hand wasn't good enough for a man like Browning. He saw the potential of what he had created and designed four more unique ways to make a handgun function, all of which had complete working prototypes by mid 1896.

John Browning had an unusual method for developing prototypes compared to his contemporaries. He would build an action using a standard, available cartridge, then once the design was fully functional he would tailor the cartridge to best suit the design. Records from this time have largely been lost if they were recorded at all. From what is available, we know that the cartridge for these first guns was based on the 38 Smith&Wesson. It is likely, but unconfirmed, that all the prototypes originally fired the standard 38 Smith&Wesson cartridge (.385”case with .361” bullet). While there is no documentation specifically regarding the 38, it is recorded that at this time Browning would personally modified cases, work up his own loads, and send them to Winchester to have their ammunition department create commercial samples. And it appears that this was how cartridge development started in Browning's first pistols. 

Between 1894 and 1897 Browning had submitted all of his pistol prototypes to Colt, which purchased limited patent rights to produce them. Colt, however, was only really interested in one of the five designs. Further development of Browning's cartridge would be tailored to his short recoil dropping barrel pistol, later know as the Colt model 1900. 
The earliest record of this cartridge development comes from the logs of the Union Metallic Cartridge Company, which Colt's used extensively for prototype projects. UMC records that 40 cartridge samples were sent to Colt on August 7, 1896, referred to as “38 S&W Headless”. Further information from UMC is not recorded until 1900, but, as already stated, we know cartridge development was also being done by Winchester, under Browning's direction. The earliest surviving cartridges are Winchester samples from 1897. The cases, .385" (9.78mm) diameter by .770" (19.56mm) long, are rimless with an overall length of 1.167”. The bullets, however, appear to be the smaller .357” as used in the 38 Long cartridge, but have not been studied to determine exact size or weight. It was these cartridges, along with Browning's pistol prototypes, that made their way to Europe during 1897, where they were inspected by a certain German firm who was already a competitor in American Military trials for automatic pistols. The Europeans rejected all of Browning's full-size pistol designs, likely to avoid domestic competition.
Back in the United States, Browning's pistol and cartridge continued development, as seen in another Winchester sample from 1898. Cases maintained their .385” (9.78mm) diameter, were lengthened to .897”(22.78mm) for a 1.303”(33.10mm) overall length, and the rim was increased from the case diameter to .401”.  Bullets appear to be the same .357”, but again have not been studied to determine exact size or weight. There is no documentation for why these changes were made, but there is debate that it may have been part of early experiments to test the feasibility of standardizing military cartridges in both an automatic pistol and revolvers. This theory is plausible given that the extremely close dimensions of the cartridge to the 38 Navy and Army cartridges then in use would allow it to be chambered in Colt's revolvers. Even today, the 38 Automatic can be chambered in many 38 special and 357 Magnum revolvers if they have relatively loose chamber tolerances. This practice is not advisable, however, due to the automatic's higher standard operating pressure.
The lengthened, semi-rimmed case, nominally designated 9x23mmSR, would be standard throughout the rest of development and production. In 1899 the Army Ordnance Board began testing the Colt/Browning pistol and cartridge. Trials documents record the cartridge as firing a 105gr jacketed round-nosed bullet at just over 1300fps, using Walsrode Green Shotgun Powder. Testing was intermittent at first, with small batches of samples being provided by UMC throughout early 1900. Maximum overall length of the cartridge was reduced to 1.275 before being put into full-scale production in March. By June 1900, two million cartridges were sent to Colt's for military trials. 
While testing was ongoing with the military Colt released their new automatic pistol to the commercial market. In commercial catalogs of this era there were so many proprietary cartridges for specific arms that they were typically listed with the caliber designation followed by the specific application, i.e. 38 automatic, Colt's pistol. The abbreviation of this advertising convention is how we got the nomenclature for this and Colt's future pistol cartridges; A.C.P.
For those of you still with us, you're probably saying “great, we got to 38 ACP, when are we going to get to 38 Super, the whole point of this video?” Actually, we're already there, you just don't know it yet. Bear with me, it's a long story.
Between 1900 and 1911 minor changes were made, with a great deal of focus given to refining the pistol and cartridge to function reliably with solid lead or soft point bullets. This was likely done for the commercial market as the military exclusively used fully-jacketed bullets due to their greater reliability.

Between 1900 and 1903 Colt's pistol and the 38 ACP saw field testing state-side and actual combat use in the Philippines. Field tests done at Fort Riley, KS by the US Cavalry returned a litany of complaints about the pistol and the cartridge's “small caliber”, but did conclude it was less prone to breakage and provided greater accuracy than the standard Colt revolvers. Changes were being made even before official reports were received and both commercial pattern and improved “Military” models were shipped to active units in the Philippines. Again requests came back for ergonomic changes to the pistol, but overall it was well received and praised for its ease of use and improved accuracy.
 Unfortunately use in the Philippines would leave all 38 cartridges of this era with a stigma of inadequacy. This however, this is largely the product of propaganda espoused by senior military officials, especially within the Ordnance Board and Cavalry, who had disagreed with the change to “small bore” pistol cartridges and sought to justify the return to larger calibers. Most reports that are used to highlight the “lack of stopping power” of the 38 Colt revolvers, if read in their entirety, detail that instances where Moro Juramentados were ineffectively shot multiple times were not only fired upon with revolvers but also with 30-40 Krag Carbines. Actual complaints from that campaign were targeted at the Colt revolver, which was prone to parts failure and difficult to repair in the field. While they did reissue 45 caliber single-action revolvers, the best solution to the “small bore problem” at the time, which was really a body armor and close range engagement problem, was the liberal use of 12ga buckshot.

In 1903 the diameter of soft point bullets was increased to .359”-.360” to aid accuracy. Also in 1903 use of Bullseye powder became standard, as it was cleaner than the previously used powder.
In 1904 the US Ordnance Board abandoned development of 38 caliber military cartridges and announced that all future cartridges were to be no less than .45 caliber. During the Thompson-Lagarde tests which were used to arrive at the .45 caliber standard, two 38 ACP cartridges were used. One fired a jacketed soft-point 120gr bullet at 1048fps, and the other a full metal jacket 130gr bullet with a velocity of 1107fps. 
Development documentation after 1904 is extremely scarce, as nearly all commercial records were discarded, and information must be inferred from advertisements and catalog listings. Between 1904 and 1911 UMC records that the only change of note was that instead of providing a cannelure on the bullets, it would be made on the case to alleviate issues with bullet jacket seperation. After 1911, available records and catalogs suggest that no significant developments were made until the 1930s.

Commercialy Colt's 38 Automatic Pistol line (1900, 1902 sporting, 1902 Military, and 1903 Pocket Hammer) did well and continued in production until 1929. The Military model was particularly popular in Central and South America and was used on all sides of the Mexican Civil War and along the border in skirmishes with Texas Rangers, who also used the pistol.

In 1920 SAMSAA, a precursor to SAAMI, published dimension standards for commercial cartridges and officially labeled the 38 ACP, “38 Automatic”. Colt must have pissed off somebody because US standards organizations did not like putting Colt's name on cartridges if they didn't have to. In 1926 SAAMI was established and immediately began consolidating and standardizing cartridge variations. During this time the wide range of bullet weights available for 38 ACP was consolidated and the 130gr bullet became standard across all manufactures. Some variation still existed, however, with velocities ranging from 1080fps to 1190fps. 

In 1928 Colt released a variation of the Government Model (M1911) chambered for 38 ACP with the model name “Super 38 Automatic”. It is a common misconception that a new cartridge was also released with the pistol, but ads, articles, and catalogs from 1928-1932 confirm the use of standard 38 ACP. The biggest culprit in the naming confusion is Maj. J. Hatcher, who wrote an article in the 1929 issue of American Rifleman in which he randomly used the term Super 38 and 38 Super interchangeably when referring to both the pistol and cartridge.
 
It was not until 1933 that a high velocity loading of the 38 ACP was introduced specifically for Colt’s Super 38 Automatic pistol. The new load pushed the standard 130gr bullet at 1300fps. 
The high velocity loads bore the same head stamp as typical 38 ACP and were only distinguished by packaging labels. Very quickly most manufactures began using nickel plated cases, likely to aid in extraction of the higher pressure cartridge, and this was the only visual distinction between standard and high velocity loads until the 1970s. Naming conventions were inconsistent between manufactures and distributors but eventually the title “38 Super” stuck and became the standard designation for the high velocity loading. 

During the 1930s the Super 38 gained popularity with law enforcement officers and gangsters alike, with the high velocity 38 ACP being touted as the most powerful 38 cartridge available before the 357 Magnum was released in 1935. Aggressive marketing by Smith & Wesson throughout the 30s and 40s successfully marginalized the Super 38 with police and sporting markets, while Colt focused on their own revolvers and military contracts of the Government Model. Over the next 30 years the Super 38 would slowly fade into obscurity, becoming the niche choice for those who considered themselves serious gunmen.

In 1974 SAAMI began to standardize high pressure variations of cartridges and added a “+P” designation to denote this standard. They got around to the 38 ACP in 1979 with published standards for; 38 Automatic at a maximum pressure of 23,000cup (26,500psi) and its high pressure variant titled 38 Super Automatic +P with a maximum pressure of 33,000cup (36,500psi). When manufactures applied these standards to the cartridges, velocity using a 130gr bullet became 1040fps and 1280fps respectively. While these new standards were a step backwards in cartridge performance they did provide a margin of safety when shooting old Colt pistols, for both the shooter and the gun. Keep in mind though, that the +P pressures are maximum safe standards. Since 1979, manufactures have been producing typical 38 Super +P with a velocity of 1215fps, a mere 25fps over the standard load used in 38 ACP for over 70 years. That doesn't sound very super.

During the 1970s the rise of competitive sport shooting caused a revival of the 38 Automatic. In competition classes where the Government Model was favored, the Super 38 offered additional magazine capacity and reduced recoil, which was especially true when combined with a compensator. When handloaders began pushing the 38 to greater pressures than before, it was limited by the pistol's chamber design which left a significant portion of the case head unsupported. In addition to allowing case expansion, this also allowed misalignment of cartridges in chambers with loose tolerances, where the rim could ride under the barrel hood and seat the cartridge too far into the chamber. This condition was aggravated by competition shooters who had a habit of undersizing cases (.381”) to increase feeding reliability. Despite this ultimately being a shortcoming of barrel quality control at the time, shooters that didn't understand the issue often had the loudest voice on the matter and the cartridge again gained an unjust stigma, as inherently inaccurate. 
During the 1980s two developments came about to fix the safety and perceived accuracy issues, both marketed by after-market barrel maker, Bar Sto. The first change was that chambers were cut with a shoulder to force cases to headspace on the mouth rather than the rim. To ensure this worked with the undersized cases (.381”) and lighter weight 9mm bullets (.355”, 124gr) preferred by competitors the chamber throat was reduced  in diameter and length. This has since become standard among manufactures despite SAAMI's refusal to publish the new dimensions, citing the possibility of increased chamber pressures. The second development was the introduction of ramped barrels, like those used on Colt's 1900 series pistols, which lengthened the chamber and fully supported the case. These developments allowed handloaders to push the cartridge to its extreme limitations, seeing pressures upwards of 50,000psi used in guns for competition and hunting. Also during the mid 80s, Para Ordnance pioneered the use of doublestack magazines in the 1911. This spurred the development of new versions of the 38 Automatic, as standard cartridges were prone to rim-lock in the new magazines. At first handloaders resorted to forming brass from 556/223, but the significantly thicker cases decreased capacity and created a potential for erratic peak pressures that could rise well above safe limits with small variations in powder charge, bullet seating depth, or even ambient temperature. 
During the 1990s a balance of increased strength and adequate case capacity was found with cartridges such as the 38 TJ, 38 Super RL and 38 Super Comp, which featured enlarged extractor grooves and a smaller rim diameter of .400” for the TJ and .385” on the RL and Super Comp. Lapua and Jagemann produced cases with an even smaller rim, .381”, to maintain a truly rimless cartridge even when undersized.
The brief popularity of the cartridge's extreme variations in competition use also fostered a renewed interest in the standard cartridge used in more basic pistol models. The late 1990s and 2000s saw what will probably be the widest variety of 38 Automatic variations and pistols chambered for them. By 2020 the only 38 Automatic variation that remained in production was the 38 Super Comp. During the mid 2010s the variety of new pistols chambered for the 38 Automatic saw a sharp decrease, however the number of manufactures producing 1911 pistols increased dramatically, and all have a model available in 38 Super. So, all things considered, there appears to be as many 38 Automatic pistols being produced today as there ever has been, it's just that they all come in a 1911 flavor. 
With the 2010s decrease in popularity however, manufacturers began taking shortcuts with their pistols that have again given the cartridge and the 1911 an undue stigma of being unreliable. As the 38 fell out of competition use, in favor of 9mm, manufacturers responded by offering the same pistols chambered for the shorter 9mm cartridge. To feed reliably and maintain accuracy magazines, feed ramps, and breachface dimensions had to be altered. The shortcut that many manufactures took was to standardize their designs on the 9mm and then simply chamber those designs in 38 Automatic to satisfy the small market demand. Doing this, however, introduced a host of problems, particularly with feeding and ejection. Unfortunately the current 38 Auto market has once again been pushed out of the mainstream where it requires gunsmiths and handloaders to keep the pistols and the cartridge operating to their full potential. For those dedicated users, though, there is a reverence for the cartridge's capability and history that will continue to carry it into the future.

If you allow for confusion in the naming convention, the 38 ACP is one of the longest continuously produced pistol cartridges, having begun in 1900, behind only the 32 ACP which began production in 1899.