With the introduction of the successful metallic cartridge in the 1840s, an explosion of innovation directed towards rapid-firing infantry weapons rocked the world. The culmination of this would be the mass-produced self-loading rifle, realized with the adoption of the Garand in 1933, its standardization in 1936, and eventually its mass production after 1939. However, the Garand was far from the first self-loader ever devised; many know of the Mexican-Swiss Mondragon rifle, but even earlier than that were the Cei-Rigotti of 1898, the STA series of rifles from France beginning in 1896, and the Madsen-Rasmussen of 1888, to name a few. Many of these early rifles worked fairly well, even; the Madsen-Rasmussen, Mondragon, RSC 1917, Mauser Selbstlader, and several other weapons were successful enough to be adopted in some capacity by military forces. Why, then, did the world have to wait until the late 1930s to finally realize the standard-issue selfloading rifle?
I. Ammunition Technology
Ever since the introduction of the centerfire rifle cartridge in 1866, military rifle ammunition has looked essentially the same. A copper-alloy or steel case enclosing the loose propellant is mated to one of a huge variety of bullet styles, with a Boxer or Berdan primer at the base. However, despite this external similarity, the ammunition available by the early 1930s was very, very different than that of the 1870s, or even 1900s. Transformative changes were made to each component of the military rifle round during this period, until the ammunition finally became suitable for use in selfloading weapons:
While it may not seem significant today, the metallurgy of both the case and projectile were a major stumbling block to reliable repeating, automatic, and selfloading weapons until the 1930s and ’40s. Problems were encountered even with something so simple as producing durable jackets for (then) high velocity smokeless powder rifle rounds, including jackets stripping off bullets in the barrel when fired. There were even major technological gaps between countries: The United States tried and failed to copy the alloy used in the German S Patrone projectile’s jacket, and early experiments with indigenous alloys resulted in failure.
Case metallurgy, too, was a significant problem; today there exist exacting standards for the metallurgical properties of military rifle ammunition (in fact, a lack of stringent enough regulations for the early .223 rifle cartridge led to significant problems in the initial fielding of the AR-15 to Southeast Asia), to ensure their reliable functioning in automatic weapons. The pioneers of high pressure metallic rifle cartridges had to contend with brass that was too hard or too soft, brass that created excess friction in the chamber, and on top of all this how to produce the millions of rounds that would be needed in a major war.
2. Powder Chemistry
In 1886, the first smokeless powder rifle cartridge, the 8mm Lebel “Balle M” was introduced. While this was a major leap in chemistry over miserably dirty black powder rifle cartridges – and though it led directly to feasible self-actuated machine guns, the early smokeless propellants were very primitive compared to the state-of-the-art propellants of the 1930s. Most smokeless powder ammunition before World War I (and even much into the 1940s) was loaded with single-base propellant, which has a much higher flame temperature, resulting in much more barrel wear and reduced sustained fire capability. These early single-base propellants were also highly unstable, resulting in wild pressure excursions into both the high and low regimes, and miserable storage lifespans by modern standards. One of the contributing factors to the eventual replacement of the 1895 Winchester-Lee rifle by the U.S. Navy was the ruin of large stocks of its 6mm ammunition due to propellant decay.
To compensate for the shortcomings of the ammunition of the time, the majority of military repeating rifles featured extensive and redundant safety mechanisms as contingencies for a catastrophic ammunition failure. The Mauser 98 rifle, in particular, is replete with multiple redundant features making it very difficult to destroy, and resistant to failing in such a way that would harm the shooter. Early selfloading rifles had to provide not only the sure integrity of the military bolt-action rifle, but also reliable and consistent functioning with what was often inconsistent and potentially dangerous ammunition, and they had to do so at much higher rates of fire.
3. Primer Chemistry
Corrosive salts in primers are notorious for their ability to corrode and ruin firearms, however, even before the introduction of non-corrosive powders, major advances in primer reliability and ignition properties were made steadily during this period. As an example, Winchester’s primers at the outbreak of World War I were the best in the world, enjoying a significant advantage in reliability and consistency when compared to their competitors’ primers. Winchester would then very generously (some would say foolishly) give away this primer formulation to its competitors in support of the war effort.
4. Powerful Ammunition
Selfloading pistols, in contrast to their rifle counterparts, took off in the late 1890s and became common in the early 20th Century. Many thinkers both then (Mauser and Luger, as examples) and now have taken this as evidence that the selfloading rifle could have been successfully fielded much earlier, as after all pistols are much smaller and lighter than rifles; if selfloading technology could be pioneered there, why couldn’t a suitable service rifle be developed?
However, these early thinkers found the problem much, much harder to solve than they expected. Rifle rounds, in contrast to those of pistols, run nearly double the pressure, and may have much wider case heads, resulting in tremendous technical challenges for the selfloading rifle designer. The high bolt thrust of rounds with high peak pressure and wide case heads was one component of this, meaning selfloading rifle locking mechanisms had to be robust enough to handle the force on the bolt (and precluding the use of the simple blowback mechanism), but also highly relevant was the much greater friction between the case and chamber relative to pistol calibers, a problem compounded by the poor powder chemistry, case metallurgy, and less precise tolerances of ammunition of the day. The early selfloading rifles, then, had to be designed in such a way that they unlocked after the pressure had receded enough to allow reliable extraction, but not before the loss of pressure to unlock the action. Today, rifles enjoy finely-toleranced ammunition with excellent propellants that are highly stable, and noncorrosive primers, and thus can extract earlier and cycle more reliably.
For many years, it was believed that a satisfactory selfloading rifle in a major rifle caliber with weight under 10 pounds simply could not be developed. So serious was this problem that the US Army pursued the development of the .276 Pedersen rifle cartridge, explicitly under the assumption that the use of the standard .30 M1 cartridge would simply prohibit the development of a suitable rifle. Garand’s highly advanced T1 .30 caliber rifle would prove this assumption false, and with that, support for Pedersen’s .276 rifle cartridge evaporated.
II. Weapons Technology
A selfloading rifle is on the face of it more sophisticated than its predecessors, but less visible to the eye are the improvements made in the materials, details of the design, and other fine aspects. The time it took to perfect these design elements meant that the effective, battle-ready selfloader was out of reach until just before World War II:
5. Gun Metallurgy
Steel comes in a dizzying number of alloys, everything from pot iron to chrome-vanadium tool grade steel. What may be surprising is that the vast majority of the high grade steels are 20th Century innovations, meaning rifle-makers of the 1870s did not have access to the nickel steels, chrome-moly steels, stainless steels, and very high-carbon steels that the later manufacturers would. Advances in metallurgy were critical to the development of the selfloading rifle; stainless steels would allow gas blocks to be manufactured that held their dimensions even when firing hundreds of rounds of corrosive ammunition, the mass production of high carbon, low impurity steels would give the Garand an operating rod that would not bend under the pressure of firing, and chrome-moly steels would give the Garand a strong, light barrel.
6. Heat Management
Early automatic weapons required the use of extremely heavy barrels, water cooling, or both to remain effective at the high rates of fire expected of them. As the development of self-loading rifles progressed, it became clear that the existing architecture of repeating rifles would not be sufficient to manage the heat produced by the new rapid-fire weapons, and as a result, many early automatic and selfloading rifles utilized large radiators or other cooling apparatus to allow the weapon to sustain a rate of fire above that of repeating rifles. Such devices, however, were heavy and added to the weight and complexity of those designs, precluding for decades the production of an effective, rapid-fire selfloading rifle for general issue. It was only in the late 1920s that selfloading rifles would catch a break, as the introduction of new steels and better powder chemistry (especially the IMR line of propellants) gave the selfloading rifle a chance to shine.
7. Exposure Resistance
A weapon that is fouled by exposure to the environment will suffer significant penalties to its operation. Corroded gas tubes, stuck breechblocks, and wood-warping due to humidity could slow or stop a self-loading rifle in ways that simpler and less sophisticated repeating rifles might soldier through. In part due to this, early self-loaders were often required to be able to be used as repeating rifles in the event that adverse conditions prevented the gun from operating correctly, a requirement that added weight, bulk, complexity, and cost. As metallurgy and propellant chemistry improved, selfloading rifles proved more and more resistant to the elements, resulting in highly effective rapid-fire rifles that could be used in any conditions.
III. Production Technology
8. Tooling and Precision
It is no coincidence that John Garand is the man responsible for the development of the first successful general-issue selfloading rifle; Garand was a genius toolmaker. Having previously worked for Brown & Sharpe as a machine tool designer, Garand not only had the technical genius to design a rifle that worked, he also had the knowledge to create the tools that would put an M1 Garand into the hands of every U.S. Army rifleman in World War II. An overlooked aspect of the production concerns of selfloading rifles is the precision of the tooling and measuring devices available. So important was this, in fact, that it was Springfield Armory who blazed the trial of ever more precise machine tools and measuring devices.
Garand’s rifle was considered by many to be un-mass-produceable. Indeed, without Garand it would never have been mass produced; he was one of the few highly skilled toolmakers left in the gutted 1930s Springfield Armory. Once the M1 had been adopted, Garand set to work designing and making both the machines that would make the rifle, and the machines that would make the machines to make the rifle, plus all the jigs, fixtures, and other production hardware needed to produce it. No other small arms designer I know of had such tremendous knowledge and skill at realizing the production of their own weapons. Thanks to the tireless work of John Cantius Garand, the infantry selfloading rifle finally was born.
For further reading on the subject, I recommend the following books:
– Proud Promise: French Autoloading Rifles, 1898-1979, by Jean Huon
– A History of U.S. Military Small Arms Ammuniton, Volume I 1880-1939, by F. W. Hackley, W. H. Woodin, and E. L. Scranton
– The M1 Garand Rifle, by Bruce N. Canfield
– The FN49: The Rifle That Ran Out of Time, by R. Blake Stevens