Handloading the Largo

While the pursuit of accuracy and high performance is interesting, we sometimes overlook the fact that handloading is the only means of obtaining a reliable supply of ammunition. So, the first need is to have something to fire in the piece. Performance and economy are secondary considerations. Such is the case with the 9mm Largo pistol. Although factory Blazer ammunition is now available, for most of my shooting career, 9mm Largo ammunition has been difficult to obtain. This is unfortunate, as the pistols that fire the Largo are often well-made, interesting pieces. On the other hand, the low availability of ammunition is among the reasons the price of the pistols has remained depressed. This is okay by me, as an inexpensive pistol taking custom ammunition fits my personal criteria well for recreational shooting.

I have experimented with several pistols in this caliber, including the Astra versions, but my favorite by a considerable margin is the Star Super. The Super is a good-looking pistol obviously closely related to other Browning derivatives, but it is more than a clone of any other pistol. It offers unique features that set it apart from the crowd when first introduced and remains modern even today. After decades of producing Browning-type locked-breech service pistols, Star introduced the Star Modelos Super just after World War II. According to historians, the pistol was produced until the early 1980s. There were many variations on the theme and factory records are scarce, but suffice to say the pistol enjoyed wide popularity. The Super was produced in 9mm Luger, 9mm Largo and .38 Super. The most common chambering seems to be 9mm Largo. The main differences in the pistols are in the breech face. The .38 Super requires a wider breech face to accept the semirimmed .38 Super cartridge. The pertinent dimensions are 9mm breech face, .384 inch; and .38 ACP Super breech face, .405 inch.

The “Super” designation denoted improvement in the mechanical aspects of the pistol, not necessarily the .38 Super chambering. The pistol has advanced features that would not be out of place on a modern 1911. These include an external extractor and a loaded chamber indicator similar to that found on my most modern 1911, the Smith & Wesson SW 1911. The loaded chamber indicator is simply a cut-out in the slide that reveals the base of the cartridge case if the piece is loaded. There is also a full-magazine indicator, simply a small piece of metal that protrudes from the bottom of the magazine if it is fully loaded. The sights are among the best of any service pistol of the era. Compare the Super’s sights to a 1950’s 1911, Browning, Beretta 1951 or French 1950 and you will see the comparisons I base my opinion upon. The sights featured a white inlay when new, but most will have long seen this inlay worn off.

The recoil spring guide is captive, and lockup is achieved by angled camming surfaces instead of the swinging link of previous Star pistols. The Tokarev and the French 1935 were the last new pistols (other than 1911 clones) to use the swinging link. The use of the High Power-type lockup allowed a revolutionary new takedown system. With the magazine removed and the slide in battery, a lever on the right side of the pistol is turned down and the slide can be removed. This is a fantastic advancement, a noteworthy improvement in service pistols that has not been adopted by other single-action service pistols. Detail changes in the magazine safety and trigger action were also introduced.

Given the improved takedown, the pistol is rather simple to field strip. It is all Browning in this regard. The safety system bears some discussion. While 1911-like, the Star system positively locked the hammer when the safety is “on.” Unlike the 1911, however, the safety may be applied when the hammer is in the down or fully forward position as well. There is no grip safety.

Overall, our Spanish friends saw the Star Super as a singular improvement over previous single-action pistols, and essentially they are correct. We probably would not have as much experience with the piece save for the importation of the Star Super in great numbers during the past decade or so. These pistols vary in age and condition, but they are available for less than $200, a light tariff for a high-quality pistol.

Feeding the Largo

The 9mm Largo is longer than the 9mm Luger. Case length is the same as the .38 ACP, .900 inch. At least that is the measurement of the majority of Largo cases. Some sources quote .910 inch as the proper length.

Modern CCI Blazer aluminum cases measure .900 inch. The case is quite similar to the .38 ACP save the Largo does not have a semirim, a design that sometimes gives trouble in the .38 Super, so its deletion is all to the good. At one time, the only ammunition available was military surplus of suspect property. Some used corrosive primers. Handloaders could not use Berdan-primed brass – at least not easily – and we really prefer not to use brass that once used corrosive primers. The obvious answer was to use .38 Super brass. Sometimes, the Super brass worked just fine. Other times, the rim hung up on the breech face. This is an individual thing, but in my experience the Star Super most often demands the correct rimless brass while others are less exact. When the piece will not accept .38 Super brass, the answer is to relieve the breech face to the proper dimension.

When the market became sufficient for factory loaded ammunition in the Largo caliber, Speer developed the Blazer loading. There are two versions, one using the 124-grain Gold Dot bullet and the other using a full-metal-jacket bullet. Each develops about 1,100 fps. This is conservative in respect to older steel but warm enough to operate the action. Berdan-primed aluminum cases are not reloadable, but at least we have a factory product for casual use. I prefer to use the correct cartridge case, as the true 9mm Largo features a larger extractor groove than the .38 Super. Common sense tells us the case the firearm was designed to accept would have the greatest potential for reliable function. Fortunately, Starline has come to our aid with quality, affordable 9mm Largo brass. This is a great boon and allows concentration on load development rather than hours spent making cases or modifying the piece.

 I have also used the Starline .38 TJ case with excellent results. This case features a large extractor groove and rimless head, making for better feed reliability in .38 Super pistols. It works fine in the 9mm Largo. The design places the case head farther into the chamber for safety. In its original form, the 9mm Largo is about as powerful as a standard 9mm NATO loading. Most common were 124-grain bullets, but some loads used bullets as heavy as 134 grains.

I am content to load the 9mm Largo in the 9mm Luger +P+ or low end .38 Super class. Most of the loads I use are geared toward informal practice, but a few top-end loads that maximize the caliber are included, and I have not observed excess pressure signs with these loadings, but slide velocity is increased and wear will be accelerated. The Largo can be quite pleasant and accurate with standard loads. Top-end loads should be reserved for occasional use, if fired at all.

Load Data

There is precious little data available for the 9mm Largo, but the case capacity and dimensions are similar to the .38 Super. I began my pursuit with loading data for the Super, beginning with starting loads. I found that as a rule the same bullet and powder charge demonstrated a bit more velocity in the Largo than in the Super, so keep a watch on pressure and slide velocity, and let caution be your guide.

Powder

I used the same powders that have given good results in the .45 ACP and .38 Super. These included Bullseye and Winchester 231. However, I used a powder that, while established as a good performer, I have had little experience with – Winchester Action Powder or WAP. I found it a good choice. The report of the WAP loads seemed greater than the others, even at moderate velocity, but overall results were good. Power Pistol had proven a good choice for heavy loads in the .38 Super, and once again results were good. The 9mm Largo, like the .38 ACP and .45 ACP, works well with a variety of powders. It is a matter of finding the “sweet spot” in your pistol.

Bullets

I used an eclectic selection of 9mm (.355-inch) bullets that have given good results in the 9mm Luger and .38 Super. None heavier than 124 grains was used, but I concentrated on the 115-grain weight, which should give adequate bullet pull and accuracy while retaining good expansion potential. I was correct, but I also enjoyed fine results with other weights. As an example, the 88- to 90-grain 9mms are sometimes a waste of time in various 9mm pistols. While high velocity is attainable, the bullet has insufficient pull for consistent powder burn, and overall the small bearing surface does not produce great accuracy. The weight seemed contraindicated in the 9mm Largo, but with a modest supply on hand, I gave them a try.

As a moderate range varmint zapper, the lightweights would do the business. At close range, expansion is violent with the Sierra bullet, usually resulting in fragmentation. On the other hand, in experiments with the .38 Super, the 90-grain XTP refused to fragment in wet newsprint, even at 1,600 fps. This is food for thought and special applications. In any case, the Largo gave fine accuracy with the 90-grain bullets. This was unexpected but pleasant.

Overall, I feel that the 115-grain JHPs gave the best results in this caliber, and accuracy results were the best obtained. I used the Nosler and Sierra JHPs with good results; both gave good accuracy. Either offers good expansion potential, with the Sierra more likely to fragment quickly. It all depends upon the scenario. For general purpose use, a bulk bullet that gave good performance is the Zero Bullets 115-grain JHP. You may ask why I use so many hollowpoints instead of FMJs, but the answer is economics. As long as the pistol feeds JHPs, why not? The Zero bullet is inexpensive and in bulk is usually the same price or less than comparable hollowpoints.

In the 124-grain bullet weight, I used the Hornady XTP and Speer Gold Dot. Accuracy was good, and top velocity resulted in a load that met steel reaction targets with a resounding clang. Those wishing to duplicate the original 9mm Largo loading may use the Hornady 124-grain Truncated Cone bullet.

Lead Bullets

The Largo proved accurate with cast bullets. The Magnus 122-grain bullet, designed for the 9mm, is a good choice for inexpensive target practice and small game. Filled with good lubricant in a wide grease groove,

leading was at a minimum below 1,200 fps. This is the ideal economy load, and accuracy potential is good with the right powder combination.

Overall, I found the loading project profitable. I used RCBS 9mm Largo dies, although .38 ACP dies will do yeoman service if you have a set on hand. Winchester primers were used in every load with good results; however, a difference in performance in magazines was noted. The magazine supplied with the pistol featured a yellow band on the base plate, probably a military mark for inventory control. It wanted to dip the first cartridge in the magazine into the feed ramp at times, compromising feed reliability. Once the first round was fired, the pistol always fed the rest of the magazine. The better performance was realized with a magazine with a solid follower, while the less reliable magazine featured a cut-out below the follower body. Either worked fine once the first cartridge was loaded, and a simple push on the slide usually completed loading with the offending magazine. If I have a choice I will take the solid follower design.

I began by cautiously using data intended for the .38 ACP then applied my own experience with the .38 Super, a similar cartridge, to the 9mm Largo. Overall, the 9mm Largo pistol and cartridge were found to be good performers. Plus, this performance is available on the cheap. That sounds like a lot of fun to me!