Chronicle of the Cartridge
| by Michael Yardley |
April, 2003 |
The word “cartridge” comes from the French “cartouche” or Italian “cartoccio”, and early examples were no more than charges of powder boxed or wrapped individually to speed up the process of loading.
Leonardo mentions the existence of paper cartridges circa 1500, and by 1600, cartridges containing both powder and ball were in widespread use. Because of the drawbacks of match, wheel and flintlocks, dramatic progress was difficult. Improved breechloaders were seen in the 17th and 18th centuries – the most famous being Ferguson’s screw-breech rifle of the 1770s. A few of the earlier designs had metal cartridges for powder and ball, but they were no more than curiosities.
Combustible cartridges containing powder and ball wrapped in nitrated paper, cloth, or skin were made in the first years of the 19th century. It was the appearance of the percussion system in 1807, however, that really sped up progress towards a fully self-contained cartridge.
Samuel Pauly, a former Swiss artillery man and veteran of Napoleon’s army, patented a breech-loading double-barreled shotgun and a metal based, partially consumable, paper-walled cartridge to go with it in 1812. It had a brass-rimmed base for gas sealing, and it also contained its own priming compound. A tiny amount of fulminate was packed into a shallow circular recess in the base, and lacquered over to hold it in place. It was not a great commercial success, and its brilliant inventor moved on to dirigible airship design, forming an ill-fated partnership with the English gun maker, Durs Egg.
In 1829, Clement Pottet, who had worked for Pauly, took out a patent for a cartridge with a removable base incorporating a pocket for priming compound, or in which a percussion cap could be placed over a central nipple. In 1836, Casimir LeFaucheux, working along different lines, patented his pinfire system. A decade later, Houllier had an idea for a base wad which expanded when fired. It overcame one of the principle deficiencies of early breechloaders – gas leakage at the breech. LeFaucheux spotted the potential, combined the Houllier wad with his pinfire concept and created the first truly successful sporting shotgun cartridge. Both gun and cartridge were displayed at the Great Exhibition in 1851.
At about the same time as the primarily sporting pinfire was being perfected, the bolt-action needle gun altered the battlefield. In this system, devised by the Prussian Johann Nikolaus von Dreyse – a manufacturer of percussion caps and another ex-Pauly employee – a long, needle-like firing pin passed through the base of a paper cartridge and struck the detonating compound which was anchored to the base of the bullet. The idea, which allowed the Prussian army to dominate central Europe for a generation, was also applied to pistols and sporting shotguns. It also led the Mauser brothers to create their famous rifle from Dreyse’s door-bolt-inspired action. In England, Needham applied the concept to a double-barrelled gun and, in 1852, patented a new cartridge in which the detonating compound was placed at the base. John Rigby of Dublin, made some beautiful Needham patent guns.
M. Flobert produced his gallery gun cartridge in 1849 – essentially a small bullet inserted in the opening of a percussion cap. Horace Smith and Daniel Wesson took this further when they created a rimmed cartridge holding a small powder charge, and developed a breech-loading revolver to fire it. It was puny, but much prized as a hide-out weapon by soldiers on both sides in the Civil War. The rim-fire cartridge, so named because the priming compound was distributed centrifugally within a hollow case rim which was struck by the hammer, became extraordinarily popular and is used to this day in both .22 and 9mm shotguns, as well as rifles and pistols.
In the early 1850s, Charles Lancaster presented an innovative design that put the detonating charge at the rear of a gas-tight case on a base disc pierced with four flash holes and covered with copper foil. This was struck by a blunt firing pin. The “Basefire” cartridge was a development of great importance – not least because the Lancaster shotgun cartridge looked so much like a modern one – and “system Lancaster” became a synonym for the central-fire sporting gun.
Pottet returns to our story because of his patent for a paper-cased cartridge with a brass head and compressed paper base wad in 1855. Its main advance was a centrally positioned detonating cap placed over a small anvil. Another Parisian gun maker, Eugene Schneider, made a similar case with a different form of anvil. The English gun maker, G. H. Daw, acquired rights to it, made further improvements and introduced his sporting cartridge to the public in 1860. Daw tried to establish a monopoly in centrefire cartridges in England, but his patent was successfully challenged by Eley Brothers in 1865. The modern ammunition era had begun.
The Cartridge Case
Until comparatively – the late 1940s – paper cartridge cases were all made with a rolled turnover, as opposed to the more efficient crimp. Crimping only became popular on paper shotgun cartridges after World War II, though it had been introduced in the Victorian era with the all-brass “Perfect”, and in the 1930s it was seen in some FN loads. The first all-plastic shotgun cases were designed by ICI in 1933, but, due to the flexing of their bases leading to failure in cap ignition, they were abandoned. The honour for developing the first successful predominantly plastic case goes to Remington, in the early 1960s.
Today, four types are seen. The most common by far is the “parallel tube”. This describes a case made with a plastic (polyethylene) tube, a base wad, usually made of plastic, but which can be made of paper, and a metal rim – typically, brass-plated steel or brass – which may vary in height. The tubing itself is rather special. It is made by the Reifenhauser system - a sophisticated extrusion process which stretches a plastic tube while blowing air through it to affect its molecular structure. The end product is a very long and strong hose-like tube that can be cut into pieces as required.
Winchester is famous for its “compression-formed” case made from a single slug of plastic. It has a conventional metal base, but is stronger than the parallel tube design because there is no separate base wad. It also has the advantage that it is made with the top thinner than the base, imparting a strength to the bottom, but making the case easy to crimp.
Then there is the modernistic ACTIV case, at its most popular a few years back, which is recognizable because it appears to be all plastic. In fact, cutting into the base would reveal a hidden steel reinforcing ring, over which the rest of the case is moulded.
And finally, we might note the existence of the excellent Gordon system case developed in recent years by the firm of Baschieri and Pellagri, in Italy. It is unusual in that, though based on the three-piece parallel tube format, it is formed differently. The tube and base wad are pushed into the metal head ring, and then rolled together to form the finished case. The base of the cartridge appears to be made of plastic with a metal rim.
Wads and Things
Eley “wire cartridges” first appeared in the 1820s, and became very popular in subsequent decades. They were, in essence, a shot cup made of fine copper wire mesh, into which the pellets were placed with bonemeal as a buffering agent. The base was covered with a paper patch bearing the number and weight of shot, and the top was closed with a wad. The cartridges were noted for their long range performance and because they did not lead the barrel.
The company also made a “Universal” cartridge intended, according to its advertisements, “to supercede the use of the shot belt; they are composed of shot packed in a paper case, between layers of soft bone dust, with a wadding attached, fitting the bore of the gun… On leaving the gun, the paper is torn to pieces, and the shot at once separate, acting precisely as a hard-hitting loose charge, but much more uniform.
Eley also offered a thick “elastic” wadding for muzzle-loaders. Of concave form, it was thought to reduce recoil, and drive shot in a more uniform manner also improving patterns.
Charles Lancaster was well known in the 1860s for his “concentrators” intended for early breechloaders, they were no more than a card cylinder about half an inch long, which fitted in the case and over the main driving wad to act as a shot collar for the shot. Later they were made with a dome at the front. They contained the pellets as they left the muzzles, and increased pattern density and penetration – by as much as 24 and 28 per cent respectively, according to Walsh – and fulfilled a similar function to a modern plastic wad. In later years, W. W. Greener marketed the “Swedish” wad for breechloaders, which had concavities at both ends” – another ancestor of the plaswad.
In the 1930s, Eley developed the “Air-cushion Wad” which was, in essence, a card cylinder, usually died purple, about half an inch in height, and crimped at both ends. Introduced to the market in 1936, it had a separate, solid card disc positioned in its middle. This was an insurance in case the propellant burned through the rear surface. The air-cushion wad was replaced by the “Kleena-wad” in the 1950s. This was made from vegetable fibre impregnated with wax, and derived its name because of its bore-scouring and lubricating properties.
Winchester-Western developed an over-powder cup made from waxed paper, and introduced it in the late 1940s. This arrangement prevented gas leakage into the shot column, and consequent pellet disruption, much more effectively than a card over-powder disc. In the early 1960s, the firm went a step further and added a plastic collar around the shot column. This may have been a response to its great rival Remington, which had been experimenting with plastic wads since the 1950s and finally introduced a one-piece plastic wad column in 1963.
Smokeless Powder
Colonel Schultze, a Prussian artillery officer, developed what was to become the first commercially successful “smokeless” propellant in the 1860s, and built a factory at Lyndhurst in Hampshire to produce it. He treated sawdust with nitric acid, and added barium or potassium nitrate. This created a relatively fast-burning powder suitable for use in shotguns – which were the first firearms to use smokeless powders – but not for rifles. The Austrian manufacturer of Schultze’s powder, Volkman, patented a process for the partial gelatinisation of propellant in 1870, using either ether or ethanol. The EC brand of gelatinised powder was introduced in 1882 and was a great success with British sportsmen.
In 1884 the French physicist, Paul Vielle, dissolved nitrocellulose in ether and alcohol, causing it to become a jelly which could be rolled into sheets and cut into flakes. In so doing, he reduced the burning rate to create an efficient propellant for rifles. This top secret “Poudre B” started something of a Victorian arms race, France being the first power to adopt a high velocity small-bore service rifle. In 1888, Alfred Nobel patented “Ballistite”, made by gelatinising nitrocellulose, using nitroglycerine itself as the solvent instead of alcohol. This was the first “double-base” powder. Two British government scientists, Abel and Dewar, had been working along similar lines and patented their famous “Cordite” in 1889 – so named because the propellant was formed in spaghetti-like strands.
As far as shotguns were concerned, the new smokeless powders were harder to ignite and far more sensitive to primer and wad type than black powder, not to mention loading pressures and turnover type. They also presented new dangers, especially the later “condensed” types that were much more powerful than a similar volume of black powder. The earlier types of powders like Schultze were called “bulk” powders because they were intended to replace black powder dram for dram. The problems were quickly overcome and, by 1900, smokeless was completely predominant. With a few exceptions, manufacturers today tend to use either single or double based powder types for their entire range of shotgun cartridges. “Progressive” is another term that may confuse in this context. It simply means that the powder burns more progressively than earlier types, liberating gas more rapidly as burning proceeds. The description first appears in a Nobel patent of 1896. The action is achieved by coating the powders with substances that inhibit burning and by altering the physical shape of the granules.
The most recent propellants have achieved the holy grail of higher velocities with lower pressures, because of their clever chemical engineering. They are harder to ignite than previous types but, with modern primers, this presents no problem. Primers themselves have evolved as much as propellants. Fulminate of mercury and potassium chlorate are no longer used because they are highly corrosive. An alternative to both, lead styphnate, was developed in Germany in the 1920s, and further improved by Remington. As late as 1950, however, corrosive primers were still in use in British shotgun cartridges.
