The Volcanic Pistol: Progenitor of Automatic Weapons

By Louis A. Garavaglia

A U.S. patent issued to a German firearms designer in November of 1902 finally gave credit where credit was due: “In different constructions of automatic firearms, the toggle-link breech mechanism of the American repeating pistol of 1854 has been employed.” So it had and employed in some of the best-known firearms of the period. The 1902 patent (#712,972), issued to Andreas Schwarzlose, covered a delayed-blowback system incorporating a clever folded-toggle arrangement. As a machine gun, the system would see widespread use through two World Wars. And in that role, it would sometimes be on the same battlefield as an even more famous arm, the Maxim Gun—another descendant of the “American repeating pistol of 1854.”

This pistol, a lever-action repeater named the “Volcanic,” was patented in February of 1854 (#10,535) by Horace Smith and Daniel B. Wesson. It was actually the outgrowth of two earlier designs, patented in 1849 and 1851.

Both of the earlier guns were repeating rifles and shared important features, such as an under-barrel tubular magazine and a longitudinally sliding breechbolt, backed by a pivoting locking block. Smith and Wesson’s big contribution was to replace the locking block with a toggle link, controlled by an underlever; and in so doing, they now had in hand a basic design that was genuinely “good.” Good as the gun was, however, its “Rocket Ball” ammunition was inherently faulty, and the company failed in 1857. At this point one of its stockholders, a successful shirt manufacturer named Oliver Winchester, took over the operation. Guided by Winchester’s faith and perseverance, the Volcanic became the Henry rifle of 1860, basically a Volcanic redesigned to take self-contained rimfire ammunition. Another redesign involving the magazine system resulted in the world-famous Winchester Model 1866 (literally world-famous—a total of 50,000 went to Turkey in 1870-1871). Further improvements brought about the long-lived “Winchester ‘73,” with its centerfire .44-40 cartridge.

The ‘73 had been in production for less than 10 years when it attracted the attention of a prominent inventor named Hiram Maxim. At the time, Maxim’s prominence had nothing to do with firearms—he was best known for multiple patents on electric lamps. His interest in firearms development had resulted largely from shooting a big-bore Springfield rifle, only to be (in his words) “surprised at the violence and force of the kick.” He then posed himself a question: could this obvious disadvantage be somehow converted to an advantage? (With that thought, he was confirming one of the observations about genius: “A genius is the only one who sees what is there for everyone to see.”) After pondering the question, Maxim worked out an idea to operate a firearm mechanism by using the force of recoil and applied the idea to a Winchester lever-action sporting rifle, patenting it in April of 1884 (#279,278). In Maxim’s prototype, the entire rifle recoiled against a separate, spring-loaded buttplate, held rigidly against the user’s shoulder; a rod linked to the toe of the buttplate extended forward to the receiver and, acting on the toggle linkage through a short lever, operated the action. Just over a year later, in July of 1885, Maxim was issued a second patent on this system (#321,513), this one showing a true machine gun.

At this point Maxim had a decision to make. Such were his talents that within a month of acquiring this patent, he was issued yet another patent (#319,596) on an entirely different machine gun—this one operated not by recoil, but by gas; a sliding “muzzle cup,” blown forward by the blast of gas coming from the muzzle when the gun was fired, cycled the action. Maxim weighed the alternatives—recoil operation versus gas operation—and decided to pursue the recoil system. (Nearly five years later, in January of 1890, a designer named John Browning applied for his own patent (#471,782) on a muzzle-blast system. Other inventions based on the same system would follow.)

Maxim’s decision to pursue his recoil-operated gun was richly rewarded. Articles about it appeared in the Scientific American and London’s The Engineer late in 1884, and in June of 1885 the New York Times printed a lengthy piece headed “Admired by the British; the Maxim Gun at the London Inventors’ Exhibition.” The article, no less than enthusiastic, said in part:

Conceive a weapon weighing only 65 pounds, mounted upon a light tripod, which pours out automatically 600 shots a minute! There is no crank to turn; there is no labor of feeding. One man simply sets the frightful stream of bullets going, and then directs it at will ... The basis of it all is the utilization of the recoil force to fire the next shot. Each time the recoil energy, instead of being wasted in kicking the gun [back], is used to eject the empty cartridge, cock the gun, place the next cartridge [in the chamber], and fire it.

The idea is as simple as the result is wonderful. The “wonderful result” became even more wonderful as Maxim refined his gun (he later called the first model “heavy and cumbersome”); he came up with at least one major variation before the all-but-final design (#367,825) patented in August 1887.

In the spring of 1888 the U.S. Ordnance Department, then well equipped with crank-operated Gatling and Gardner guns, finally got a .45-70 Maxim for limited trial. Much of the ammunition was of the old folded-head, copper-cased variety, and during the firing tests some of the case heads either bulged badly or burst altogether. Nevertheless, the Maxim proved capable of pounding out 290 rounds in just 29-1/2 seconds and spit out 100 rounds in just over nine seconds.

Summing up its findings, the Ordnance board declared that “this gun is compact, portable, not complicated in construction, easily directed, requires but few men for its service, is extremely rapid, and, so far as the limited trials indicate, certain in its action ... .” A second Maxim gun underwent testing in November and December of 1889, and although problems occurred with spring breakage and misfires, the board was nonetheless impressed with the Maxim’s “novel and ingenious features,” and recommended putting one or more into actual service—among the first of thousands to see usage by the military.

For those readers not privy to Ordnance Department reports, the Maxim continued to get its share of outside publicity. Between the spring of 1887 and the fall of 1889, additional notices about it appeared in the Scientific American, the Scientific American Supplement and The Engineer. Those readers not especially interested in scientific matters could still find write-ups about it in any number of newspapers and even in Hilaire Belloc’s book The Modern Traveller:

I shall never forget the way That [Bill] upon this awful day Preserved us all from death. He stood upon a little mound, Cast his lethargic eyes around, And said beneath his breath, “Whatever happens, we have got The Maxim gun, and they have not.

Again, the heart of Maxim’s design, reaching from the Volcanic through the Winchester ‘73, was the toggle-link action. (In a firearm, the basic toggle-link action comprises two steel bars or “links,” one behind the other, with three steel pivot pins passing through the linkage at the front, rear and in the middle, the middle pin holding the inner ends of the two links together. The whole assembly is analogous to the human arm, with its pivot points at the wrist, elbow and shoulder, or the human leg, with pivot points at the hip, knee and ankle. When all three pivot points are in line with one another, the linkage is at its maximum length and resists any endwise pressure; but when sidewise pressure is applied to the middle pivot (e.g., the front of the elbow or the back of the knee), the linkage buckles or collapses, bringing the front and rear pivot points close together. In his initial design, Maxim, instead of calling his components “links,” labeled one of them the “connecting rod,” and the other the “crank-shaft,” adding to one side of the crankshaft a “weighted lever, serving the purpose of a fly-wheel.” (Parts of the patent text suggest an automobile engine rather than a machine gun.) Regardless of what name Maxim applied to his components, he nonetheless based his design on a toggle-link action, skillfully adapted to fully-automatic fire.

Simply stated, Maxim’s assembly comprised a barrel, a barrel extension (or receiver), a bolt and the toggle linkage; the barrel extension, rigidly secured to the breech end of the barrel, provided a housing for the bolt and toggle links.

This entire assembly (including the barrel) rested in a frame and was capable of sliding a short distance within the frame, a spring pressing it forward. When ready to fire, the bolt rested against the cartridge in the chamber, a straightened toggle linkage keeping the bolt in place. Upon discharge, the cartridge case, pressing against the bolt face and the extended toggle behind it, forced the whole assembly—barrel, barrel extension, bolt and toggle linkage—to slide rearward, until the toggle struck a fixed cam on the frame and buckled, thus opening the bolt, extracting the fired case and positioning itself to feed the next cartridge into the chamber.

Presumably, one of the readers of the various newspaper or magazine articles about the Maxim Gun was another arms designer, German-born Hugo Borchardt, who had come to the States in his teens. By the late 1880s Borchardt was perhaps best known for his redesign of the time-honored Sharps buffalo rifle—he had altered the original cartridge model, with its big outside hammer and double-angled firing pin, to a sleek, automatically-cocked, striker-fired arm. Beyond that, he designed an experimental revolver for Winchester which, through no fault of his, never reached the production stage.

But at some point Borchardt settled on the idea of a Maxim Gun reduced to the size of a one-hand firearm and patented his concept (#571,260) in England and Europe in the fall of 1893, while living in Germany. Within a year, the first production samples, made by Ludwig Loewe of Berlin, were ready for the market. Publicity was not long in coming; as early as October of 1894, the New York Times noted that “A curious pistol, of German invention, is exciting the wonder of military men. An [American] army officer, recently in Germany, secured one of the pistols, only a very few of which have been manufactured, and has reported in very complimentary terms of the contrivance, which is known as the Borchardt automatic repeating pistol.” Another article on the pistol, with multiple illustrations, appeared in London’s Engineering in May of 1895, reprinted in the Scientific American three months later. Moreover, published reports of successful firing tests conducted between 1895 and 1897 by several different agencies (including the U.S. Ordnance Department) drew additional attention to the piece.

Despite the praise, sales were slow. The Borchardt had an awkward, ungainly appearance, caused partly by an elongated bulge or swell at the rear of the frame which housed the heavy V-spring used to drive the bolt and toggle linkage back to the firing position after recoil. Apparently the pistol’s advanced features—a self-loader, firing a high-velocity bottle-necked cartridge and having a detachable box magazine housed in a hollow grip—were not sufficient to win over potential buyers. Fortunately, however, the situation was correctable. For several years Borchardt had worked on various projects with another designer, George Luger. And as Borchardt had once altered and improved the old Sharps buffalo rifle, so Luger now altered and improved the Borchardt pistol. He changed the grip angle, discarded the V-shaped recoil spring at the rear of the frame and reshaped it to fit inside the grip behind the magazine. This allowed him to shorten the rear of the frame somewhat, improving the appearance considerably. (This transitional Borchardt-Luger is shown in Luger’s U.S. patent #639,414 of 1899.) Further refinements between 1900 and 1906 resulted in a handgun known world-wide as the “Luger,” and one as famous as any ever made. Commercial sales in the States began in 1901 (as did field trials with the U.S. Cavalry) and were brisk until the onset of World War I.

To many of its owners, the Luger undoubtedly represented the ultimate application of the toggle-link principle to an automatic or self-loading arm. But at least one experienced designer, Andreas Schwarzlose, saw room for improvement. Prior to 1900 all the successful designs of the type, from Maxim’s through Borchardt’s to Luger’s, had required the rearward sliding of an entire assembly, including the barrel, to function properly.

Schwarzlose concluded that manufacture could be simpler and cheaper if the barrel could remain fixed during the firing cycle. But then, without the rearward shift, what would cause the toggle linkage to open?

Schwarzlose concluded that, by moving the middle pivot pin of the linkage slightly out of alignment with the other two, endwise pressure alone would cause the toggle to open; and since the middle pivot was only slightly out of alignment, fairly high pressure would still be needed to force it open. Moreover, since one of the pivots could be out of alignment, then the linkage could be folded over on itself, resulting in a notably shorter action. So in the Schwarzlose design, the toggle was folded (or “buckled”) when ready to fire and extended itself as the bolt opened.

The U.S. patent issued to Schwarzlose in November of 1902 (#712,972) specifically mentioned that his breech mechanism “may be employed for machine-guns with fixed barrel,” and the design became best known in that connection—the guns variously designated as the Models of 1905, 1907 or 1907/ 12, depending on refinements.

Another U.S. patent issued in 1905 (#804,506) showed the design as a pistol, but apparently Schwarzlose never pursued either a pistol or rifle version, turning his attention instead to a blow-forward pocket pistol.

A rifle on his principle did materialize, but in other hands. In June of 1927 an American designer, John Pedersen, applied for a patent on a “Magazine Rifle” (#1,737,974), which in essence was a highly efficient variant of Schwarzlose’s delayed-blowback idea. Pedersen was already prominent due to his design of various Remington sporting arms and was recognized in U.S. Ordnance circles because of the “Pedersen Device,” an ingenious little unit which replaced the bolt in a Springfield service rifle, and allowed it to pump out pistol bullets as fast as a soldier could pull the trigger. World War I ended late in 1918, shortly before the device was ready for issue, but within two years the U.S. Army began serious experiments with semi-automatic rifles, and Pedersen took note. After considering various alternatives, he settled on a concept similar to Schwarzlose’s. As he explained in his patent:

A feature of the present rifle which contributes in large degree to its lightness and simplicity of construction lies in the recoil method of operating the automatic mechanism, in combination with a fixed barrel ... The cumbersome and more complicated mechanism of a gas operated gun or one with a moveable barrel is thus avoided the breech mechanism preferably employed is of a construction somewhat similar to a toggle, [with] the parts being so designed and arranged that [rearward] force [of the cartridge] instigates a very slow opening of the breech.

Pedersen worked out the design over several years, using the basic toggle linkage with the out-of-line middle pivot, but instead of folding the links as Schwarzlose had, he maintained the older extended-link arrangement. To this arrangement, however, Pedersen added an important feature: the inner ends of the front and rear links were in contact with each other and were contoured to delay rapid buckling of the linkage under pressure. (This is fully explained in Pedersen’s patent.)

The rifle proved so promising that in 1927, when Pedersen applied for his patent, Springfield Armory was in the process of completing 20-odd samples for field trials. Success in these trials led to more detailed testing at Aberdeen Proving Ground in 1929, with the Pedersen pitted against rifles by Thompson, Colt-Browning and a Springfield Armory designer named John Garand. Ultimately, Garand’s gas-operated design won out. Nevertheless, Pederson’s rifle was well liked by most of those who handled it—well enough liked so that Vickers-Armstrongs of London built a limited number for sale in the early 1930s. In the fall of 1931, an official of the Samuel M. Green Company of Springfield, MA, sent a letter to Army Captain E. D. Porter, then in Oregon: “There is being shipped you by express today one Pedersen self-loading rifle, Serial No. 23. This is one of the old lots of rifles which was tested in 1927 and in the fore part of 1928 at Ft. Benning. You may have some fun with this during the deer season ... I am sorry that I have not yet one of the latest model rifles but expect to have some early in the coming year.”

In addition to his own important input, Pedersen’s rifle combined the best features of the Maxim and the Schwarzlose. Perhaps in deference to the old master, Pederson’s patent referred to his toggle links as the “crank” and “conrod” (connecting rod), as had Maxim’s patent of 1885. Regardless of terminology, all these guns—the Maxim, the Borchardt, the Luger, the Schwarzlose and the Pedersen—stand as a tribute to Smith & Wesson’s “American repeating pistol of 1854.”

AUTHOR’S NOTE: All patent numbers herein refer to U.S. patents, and all are easily downloaded from the U.S. Patent Office website (www.uspto.gov).

This article first appeared in Small Arms Review V22N3 (March 2018)
and was posted online on February 9, 2018


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