9x23mm Largo

9x23mm Largo Comparison

It came from Mars

The 9x23mm Largo has gone by a number of names over the years, with the names, 9mm Largo, 9mm Bergmann–Bayard, and 9mm Bayard Long all being used to refer to the venerable round. First developed in 1901 for the Bergmann Mars Pistol, the cartridge and pistol combination underwent two years of refinement until being finalized in 1903.

After being adopted by the Spanish Army in 1908 the 9mm Largo would see use in many pistols, machine guns, and carbines. The round would be the preeminent round of Spanish Military and Police pistols until as late as the 1980’s. Until finally being replaced by other options.

Mr. Bergmann I presume?

The 9mm Largo was first developed by German industrialist Theodor Bergmann. Bergmann was not, ostensibly, a firearms manufacture and focused much of his efforts on automobiles and bicycles, eventually selling his automotive manufacturing to Carl Benz (yes that Benz). Despite his focus on transportation, it was his firearms that would bring him the most acclaim. However, a number of his most successful firearm design’s manufacturing was done by others under licensing.

In 1903 Bergmann submitted the 9mm Largo cartridge and his Bergmann Mars Pistol to the Spanish Army for testing as a standard issue sidearm. The Bergmann Mars Pistol went up against other firearms such as the Mauser C96 and the Luger. Once formally adopted Bergmann found himself unable to find a German shop able to complete the 3,000 Pistols that he needed for the Spanish Military. Undaunted, he turned to the Belgium manufacturer, Anciens Etablissements Pieper. They were able to complete the order and deliver the pistols in 1910, two years after its official adoption.

The Spanish Military was not the only ones to be impressed by the 9mm Largo and the firearms chambered for it. In 1910 the Danish Military adopted the Bergmann–Bayard model 1910 pistol. This pistol would remain in production for the Danish Military until 1935. Below Ian at Forgotten Weapons talks about the Bergmann Mars Pistol.

Wait, haven’t I seen that before?

The 9mm Largo shares some case dimensions with two other rounds. Externally the 9mm Largo is the same as the 9×23 Winchester and the 9x23mm Steyer. While a pistol chambered in 9mm Largo can chamber 9×23 Winchester, the Winchester round has a much higher max pressure, and thicker case walls to compensate. Catastrophic failures could happen if one were to try to shoot the newer round in an older, 9mm Largo pistol. In short, do not try to exchange these two rounds in a pistol. The 9x23mm Steyr shares a number of external case dimensions with the Largo as well, however they are different enough to make them non-interchangeable.

While the 9mm Largo round was considered to be strong for the time it was first produced, the standard, modern, 9mm Luger loadings just edge out the older round. With 9mm +P, the difference grows. This helped to contribute the eventual dropping of the round. Additionally much of the advancements in bullet and powder technology have been aimed at other rounds, further push the 9mm Largo to the back of the pack.

Hand loading and factory ammo

9x23mm Largo
9x23mm Largo – Image Via Wikipedia

Factory ammo for the 9mm Largo has become scarce at best. Blazer was the most common a few years ago, however as of this writing, 2016, we can only find one current manufacturer of 9mm Largo, factory new, ammo. Good To Go Ammo seems to be the only one offering new ammo. For hand loaders, load data is somewhat difficult to find, and the real stumbling block to loading this round. Starline offers new 9mm Largo Brass, and modern powders will work in this round. We were able to dig up some reloading data from 9mmlaro.com for our readers to use.

Chambered Firearms

Many different firearms were chambered for this round. The previously mentioned Bergmann Mars Pistol, and the Bergmann-Bayard 1910 were two of the first to be chambered for this round, and help to popularize it. The Star Modelo Super was chambered in 9mm Largo and very similar to the Browning 1911 in function. The Star Super was one of the more common later pistols chambered in this round, before it fell out of favor. While an exhaustive list would be far too long for this article some of the other notable guns chambered for the 9mm Largo include:

Times Change

While the 9mm Largo spent decades as one of the top cartridges for the Spanish Military and Police, today it is obscure in the US Market and impossible to find in production guns. With the Spanish Military moving to the 9mm as its preferred round and the 9×23 Winchester doing everything it did, but better, it’s safe to say that this cartridge time has, sadly, passed. However, it is fair to say that its spirit lives on in other rounds.