Barrel Making: Making a Modern Steel Barrel - Part II

In our previous post, we saw how what kinds of steel are chosen to make barrels and the process by which they are drilled. Now we will continue discussing the process, after the barrel has been drilled.

As we noted in our previous post, a deep hole drill bit is designed to drill a hole slightly smaller than the desired bore. For instance, if the final gun barrel is supposed to have a bore of 5.56 mm., the drill bit might drill a hole about 5.35 - 5.40 mm. in diameter. So the next operation to be done is called reaming and the process uses a reaming machine to do this.

Reaming

The picture above is a reaming tool. A reaming tool is made of either tool steel or (in more modern times) tungsten carbide. A typical reaming bit is a cylindrical tool which has a set of multiple straight or helical cutting edges which are parallel to each other on the circumference of the cylinder. A reaming tool only removes a small amount of material (typically between 0.1 and 0.2 mm. at most) and is used to perform accurate sizing of a bore's diameter and also produce a smooth finish on the inside of the barrel. The white part in the picture above is just soft tape and is present to prevent the reamer from vibrating when it is inside the barrel.

The reamer bit is put in through the barrel and then oil is pumped in, but at a lower pressure than the drilling operation we saw in the previous post. Unlike drilling, in the reaming operation, the reaming tool is rotated and the barrel is kept still. The reaming tool is rotated at speeds of 200 - 500 rpm or so and the barrel is pulled through the reaming tool at a rate of about 2 - 5 cm. per minute or so. The oil keeps the reaming tool cool and flushes out any metal filings. In the picture above, you can see the reaming tool coming out of the barrel and dirty oil coming out of the barrel as well. The oil is filtered by a series of sieves to remove the metal particles and the oil is recycled.

Reaming produces a much more smoother finish than drilling and only removes a small part of the material, hence this is a finishing up operation. Some low quality barrel manufacturers skip the reaming operation altogether and merely drill the hole to the desired bore, which saves a bit of money, but doesn't provide a dimensionally accurate hole. All quality barrel manufacturers invariably drill a hole a little smaller than the desired bore and then use a reamer to make it the exact diameter and finish the insides with a smooth finish.

Rifling

The next process after reaming is done is to add rifling to the barrel. We've already studied the various methods of rifling previously (i.e.)

• Cut Rifling
• Broach Rifling
• Button Rifling
• Hammer Forging
• Flow Forming
• Electro Discharge Machining (EDM)
• Electro Chemical Machining (ECM)

We will not talk much about the rifling techniques here, since they've already been discussed. Cut rifling is generally preferred by small custom barrel makers and the last four methods are used by larger gun making companies. Note that broach rifling, button rifling, hammer forging and flow forming add additional stress to the barrel due to their methods of machining.

Stress Relieving

Because of the drilling, reaming and rifling operations, considerable stress is induced into the barrel and this needs to be stress relieved again before further operations can happen. If you remember, we mentioned that the barrel blanks are already stress-relieved by the external vendor before they're delivered to the barrel maker. This operation needs to happen again after the rifling operation is done, because the above three operations introduce considerable stress on the barrel and may cause it to deform in the next few operations if this isn't done.

There are usually two ways of stress relieving a barrel. The first way (traditional method) is to heat the barrel to about 525 - 550 degrees centigrade and then let it cool slowly back to room temperature. The second method (cryogenic stress relieving) is to cool the barrel to extremely low temperatures (say -185 degrees centigrade) and control the cooling time and temperature cycle. At this temperature, the molecules that were pushed out of the way during the machining operations are realigned again and this relieves the stress on the barrel.

Profiling or Contouring

After the rifling operation is done, the barrel may be profiled or contoured on the outside. Basically, when a gun is fired, the most pressure occurs on the breech end of the weapon (i.e.) the side where the cartridge is, and the least pressure is at the other end of the barrel (i.e.) the muzzle. Hence, it is not necessary for the barrel to be of uniform thickness throughout the length of the barrel. Several manufacturers reduce the weight of the gun by removing material from the outside of the barrel, so that the walls of the muzzle end are thinner than the walls on the breech end. This operation is called contouring or profiling.

These days, most contouring operations are done using a Computerized Numerically Controlled (CNC) lathe. The precise profile of the outside of the barrel is fed into a computer, which controls the lathe and produces the desired profile on the barrel.

Note that if proper stress relieving was not done earlier, the act of contouring may distort the barrel. This is because the stored stress from the earlier processes will start to act upon the side of the barrel where the outside is thinner and the bore will become bell-shaped.

Lapping

The final process done to the steel barrel is called lapping. Generally, lapping is only done to really high-end custom made barrels and is not normally done on mass-produced barrels. The reasons to perform lapping are to remove any machining marks, surface polish the inside of the barrel, eliminate any tight spots etc. This operation is generally a manual one and is done by an expert. 

Initially a rod similar to a cleaning rod is pushed into the barrel. Then the barrel is placed vertically and molten lead is poured down the other end of the barrel and allowed to solidify. When the lead has solidified, it is shaped exactly like the shape of the inside of the barrel. The lead lap is then extracted and lapping paste is added to the outside. Lapping paste is similar to the paste that is used to grind valves in automobile engines. The rod is then pulled and pushed through the length of the barrel multiple times and more paste or oil are added as needed. This process polishes the inside of the barrel to a very fine surface.

After this process, the barrel may be mounted to a stock, sights may be attached on the exterior, it may be chambered for a given cartridge and the barrel itself may be blued or browned along with the action of the gun.

Barrel Making: Making a Modern Steel Barrel - Part I

We've seen in our previous post that with the rise of smokeless powders replacing the old black gunpowder, steel barrels became more popular as these could withstand the higher pressures generated by smokeless powders. We will now study some of the processes involved in making a modern steel barrel.

Materials Used

Steel is used obviously, otherwise we wouldn't be discussing it in this chapter :). The steel used has to be able to withstand high pressures of over 50,000 psi (340,000 kpa) and special steels are needed to do this. There are two types of steel generally used in modern barrels:

The first type is an Chrome-Molybdenum steel alloy (called chrome-moly for short). This is the same steel alloy that is used to make truck axles, connecting rods and propeller shafts. In the US, such steels are designated by grades such as AISI 4140, AISI 4150, AISI 4340 and so on. The British equivalent of these steels is EN 19, EN 24 etc. These steels are generally used for military grade firearms as well as hunting rifles.

The other type is a stainless steel alloy such as 416 type stainless steel. This is not a true fully austenitic stainless steel such as the types used in making cutlery items like knives and forks. The 416 type stainless steel is a martensitic steel which can be hardened by heat treating, similar to carbon steel. It is more accurately a high chrome content (> 10%) steel having enough sulphur to give it good machining properties. This steel is generally used by target shooters and is considered to be easier to machine accurately than chrome-moly steels. It is also more expensive than chrome-moly steel, has lesser life and is more difficult to black. Hence, military and hunting rifles use chrome-moly steel while target shooters prefer stainless steel.

Whatever the type of steel chosen, the most important characteristics of the steel are ease of machining, longevity and strength. Secondary considerations are resistance to corrosion and ability to be blued.

It is important for these steels to have high tensile strength (i.e.) resistance to being pulled apart. These steels can easily withstand over 100,000 psi which is quite a bit over the maximum expected pressure. Hardening steels generally increases tensile strength, but it tends to make them brittle and susceptible to hard knocks, hence these steels must withstand shock as well. A tradeoff is made between tensile strength and impact strength and therefore, the barrels are hardened to between 25 and 32 on the Rockwell C hardness scale.

The steel for the barrels is generally not made by the barrel makers themselves, but instead arrives from external vendors in lengths of 5 - 7.5 meter (16.5 - 24.5 feet) long cylindrical bars and diameter depending on the barrel makers specifications. For instance, barrels intended for hunting rifles have a diameter of 3.25 cm. (1.4 inches) and barrels for smaller .22 rifles may be 2.5 cm. (1 inch) in diameter. The external vendor generally stress-relieves the steel bars before delivery. This is done by heating the bars to 525 - 550 degrees centigrade (977 - 1022 degrees fahrenheit) and then allowing the bars to cool slowly. If the bars are not stress-relieved before hand, they may split during the machining process.

The first step of the process is to cut the bars to the required length of gun barrels (e.g. 16 inches, 18 inches, 20 inches, or for metric speakers, 450 mm. or 500 mm. or whatever) and the ends are squared off. Then a hole must be drilled into the barrel.

Drilling Techniques

Everyone knows how to drill a hole into a wooden plank or wall, using a small hand-drill or power drill. Some may have seen or handled a drill press in a machine shop and used it to drill into a mild steel plate. Drilling a hole into a gun (especially rifle barrels) is a completely different proposition than drilling a hole into a wooden plank or a mild-steel plate. For one, a rifle barrel is a lot longer and the drill needs to penetrate deep into the barrel. The second problem is accuracy. For a gun barrel, it is critical that the drill does not deviate much from the center of the barrel, and this has to be true for the entire length of the barrel, which may be 40-50 cm. long or more. This means the ratio of diameter to length of the hole is unusually high for gun barrels. For example, an M-16 rifle barrel has a diameter of 5.56 mm. and a length of 508 mm. (20 inches), which means the ratio of length to diameter of this barrel is approximately 91:1.

The way to drill into a barrel is to use a special deep hole drill (also called a gun drill) and a special drill bit. First, we take a look at the drill bit used:

The drill bit is made of tool steel or tungsten carbide (these days, tungsten carbide is more common). The diameter of the drill bit is slightly smaller than the required diameter of the barrel. For instance, if the barrel bore is 5.56 mm, the drill bit is designed drill a hole slightly smaller than this (say 5.35 - 5.40 mm.) Note that the drill bit is asymmetric (V-shaped) and only has a cutting edge on one side. The drill bit is also ground so that the forces acting on the cutting edge will keep the drill bit centered in the work piece automatically. The drill bit is also hollow, as can be seen by the two holes at the end of the drill bit. The drill bit is mounted to a steel tube and then oil is pumped under pressure through the drill bit holes. As the drill bit makes its way through the barrel, the oil serves to keep the drill bit cool. Also, the metal shavings are carried out of the barrel by the oil via the V-channel in the middle of the bit. The oil is then passed through a series of sieves to filter out the metal shavings and the oil is recycled into the main tank.

In some other drill bits, there is a single hole in the middle. Oil is pumped through the V part and the oil and metal shavings exit through the hole in the drill bit.

Now we look at the deep hole drilling machine that uses such a drill bit.

In this machine, you can see a pressure gauge B at the bottom end of the photo. The oil is pumped through the pipe A into the drill bit. The barrel blank to be drilled is mounted to the chuck D on the top part of the photo. The drill passes through a couple of guide bushes (C) before entering the barrel. The guides may be seen in the middle of the photo.

The barrel is usually initially pre-drilled to a few mm. depth before being mounted to this machine, to give the drill bit an initial starting hole.

In most deep drilling machines, the drill bit is held steady and the barrel is rotated around it at speeds of 2000 - 5000 rpm. In some newer machines, the barrel is held steady and the drill bit is rotated. In some cases, both are rotated. However, the technique of holding the drill bit steady and rotating the barrel is preferred because this method keeps the drill bit self-centered.

Oil is pumped at high pressure from the end A seen at the bottom of the picture. You can see the dirty oil carrying metal shavings coming out of the channel E near one of the supporting guide bushes in the middle-right of the picture. This oil is passed through a series of filters to extract all the metal shavings and the oil is then recycled back into the main tank.

The drill bit is fed into the barrel at a slow rate of approximately one inch (2.5 cm.) per minute, so a 20-inch M-16 rifle barrel will take approximately 20 minutes to drill completely. The drill bit is initially held in the straight position by the guide bushes and prevented from moving side to side, but as it penetrates deeper into the barrel, the sides of the hole itself prevent the bit from moving around too much. Variations in the consistency of the barrel material can also cause the drill bit to wander a little. The barrel must also be straightened (or trued) before being mounted on the deep drill, because the barrel is rotated at high speed during the drilling process and any imbalance in the shape of the barrel will be magnified when it is spinning at such high speeds.

As we noted earlier, the drill bit is designed to cut a hole slightly smaller than the final diameter of the barrel. So if the desired final diameter is 5.56 mm., this process drills a hole that is 5.35 - 5.40 mm in diameter. The next process that we will study is used to enlarge the barrel to its final diameter.

Barrel Making: The Rise of Steel Barrels

In the previous few posts, we've seen a lot of detail about the so-called damascus barrels. We've also seen a genuine damascus barrel is very beautiful and requires a lot of labor to produce and is therefore expensive. In our last post, we also saw how fake damascus barrels were produced. The number of cheap fakes that were produced served to lower the public's perception of damascus barrels in general, because the fake barrels burst a lot easier and wore out quickly.

Meanwhile, various steel-making processes were improving and some of the prominent steels in the late 1800s were the Whitworth Fluid Compressed Steel, the Siemens-Martin process steel and Krupp Steel.

Whitworth fluid compressed steel was invented by Mr. Joseph Whitworth, who we already talked about when discussing polygonal bore rifling and the Whitworth rifle. Mr. Whitworth was the eminent mechanical engineer of his day and came up with a way of producing a stronger cast steel. His process consists of melting a steel ingot into a mold and applying pressure of up to 6 tons/sq. inch to the mold while the steel is in a liquid state. The pressure drives out all the gases and eliminates blowholes in the cast steel. It also increases the density and strength of the steel. According to W.W. Greener's book, The Gun and its Development, with the introduction of choke boring in shotgun barrels, whitworth steel was found very suitable for this process and started replacing damascus barrels, and he mentions in 1875, "Whitworth steel was giving great satisfaction for rifle barrels, a leading London gun-maker adopted it for shotgun barrels." The leading London gun-maker was Purdey & Sons, who used Whitworth steel exclusively for years after that. Use of Whitworth steel for gun-making spread to America as well and well known makers such as Parker, L.C. Smith and Lefevre were making guns using this steel, way into the 1930s.

In the Siemens Martin process, pig iron is melted in a reverberatory furnace and wrought iron or iron ores are added until a desired degree of carbonization is reached. Oxides are removed and manganese and carbon are added by using a small quantity of ferromanganese. The amount of carbon left is ascertained by dipping a small ladle into the melted metal and cooling it and then breaking it apart and analyzing it. If found to be the right amount, the rest of the metal is poured into ingots and allowed to cool. Then the ingots are passed between rollers to reduce the thickness to the desired size. This process is slower than the Bessemer process, but it allows the manufacturer to more precisely produce the desired grade of steel of a uniform quality.

Another big manufacturer of barrels using the fluid-steel process was Krupp of Essen, Germany. Krupp's process used a slightly different composition of steel and was also used by several gun makers.

In 1888, the Guardians of the Birmingham Proof House (a British Government organization whose responsibility was to test all gun barrels made in the Birmingham area) ran a test on the strength of several gun barrels. The board appointed a committee composed of representatives of various prominent manufacturers of the area and ran the same tests against a series of barrels of five types:

1. English damascus twist barrels, hand forged (3 specimens)
2. English damascus twist barrels, machine forged (17 specimens)
3. Foreign damascus twist barrels (6 specimens)
4. English steel barrels (11 specimens)
5. Foreign steel barrels (2 specimens)

In all, thirty nine specimens of barrels were tested, with a total of 117 different barrels used for testing. The barrels were initially loaded with a standard Proof House test amount of gunpowder and shot, using the same machinery to load, to ensure that the amount of tamping down of gunpowder and shot was uniform. Then all barrels were fired and then checked for signs of bulging and those with bulges were rejected. The next test used a heavier gunpowder charge and heavier shot and the remaining barrels were fired again and tested for bulges and the tests were repeated using more and more gunpowder and shot.

The following screenshot shows the results of the top 20 barrels (image courtesy of G.T. Teasdale-Buckell's Experts on Guns and Shooting, page 540):

We have already discussed damascus barrel grades such as the "laminated steel" and "best damascus steel" in this post previously. The best barrel was a laminated steel (a type of damascus steel) barrel, followed by a Whitworth fluid steel barrel, followed by another damascus steel ("Best damascus" grade) and a Siemens-Martin steel barrel. Note how English barrels dominate the test because some of the foreign types (especially Belgian barrels) used weaker iron in their manufacture. While Whitworth steel finished second in this test, they were just getting started in perfecting the technology and it soon became a lot cheaper and faster to manufacture as well. By 1895, when they held another test, Whitworth steel came first in this test.

The rise of smokeless powders also had a lot to do with the decline of damascus barrels. Smokeless powders generate a lot more force than black powders. Smokeless powders also burn along the length of the barrel since they're slower burning than black powders, which mainly burn at the breech end and blow out an unburnt quantity out of the muzzle. Many damascus barrels couldn't withstand such pressures and those that could needed a lot more time and effort to manufacture. Hence steel barrels became more and more popular as smokeless powder became prevalent.

The next post will deal with manufacturing of modern steel barrels.

Barrel Making: Fake Damascus Barrels

In our previous three posts, we saw beautiful examples of damascus barrels and studied the method of manufacture of these barrels. Due to the labor intensive nature of manufacture of these barrels, these were reserved for use with fine shotguns and revolvers. Thus, the presence of a damascus barrel on a gun was the sign of a high-quality and expensive product. However, some unscrupulous manufacturers soon found some ways to make inferior copies of these products, which they could then sell at a higher price as quality weapons.

One of the ways to do this was to take a barrel made of very cheap iron and then wind a very thin layer of superior damascus steel on the outside. An illustration of this process is shown below:

In the above, an inner tube is made of cheap iron. You can see the fibers of this cheaper iron tube, which run horizontally along the tube. Around this is wound a thin strip of damascus steel. You can see how the fibers of the damascus steel run along the length of the spiral. When the two are welded together, this has the appearance of a genuine damascus barrel and can only be told apart when pickling in acid, as the cheaper iron on the inside gets eaten away much faster than the surface layer. This practise was heavily used by some counterfeit manufacturers in Liege, Belgium.

Another way to imitate stub damascus is to use a cheaper iron. Real stub damascus steel is made using iron from old horse-shoe nails, which are melted along with steel from broken files and coach springs in a puddling furnace, which makes the blooms used to make the rods used for damascus steel. The cheaper technique was to use scrap cuttings of iron and put them in a charcoal furnace (instead of a puddling furnace) and then stain them in a particular way to resemble the watering pattern of damascus steel. The counterfeiters would stain the barrels very dark and then, a weak solution of muriatic acid would be applied with a sponge to those areas where the staining was darker, to make it more even. Then they would scald the barrel in hot water to stop the staining process. The result was very hard to tell apart from the real thing, except by subjecting the barrel to stress testing. This technique was common in England, as well as parts of Europe.

Similarly, barrels made of "threepenny skelp", "twopenny skelp" or "sham damn skelp" were made of very inferior materials and sold as damascus steel barrels. In most skelp barrels, the rods were not twisted together before manufacturing and hence the grain of the iron would be different from that of a damascus barrel. The solution to this was to paint on a cheap stain that resembled a fine English twist barrel, or put cheap engraving on the outside to resemble a damascus twist. One way to find out fakes was to remove the barrel from its wooden stock, because the forgers usually didn't bother to touch those parts which are hidden by the wood.

As you can see in the above, this fake damascus barrel gun hasn't aged very well due to its inferior materials. It is made of cheap iron and has an engraved twisted pattern on it to try and imitate the patterns of a low-end or single twist damascus barrel.

In our next example above, the barrels are also made of cheap iron, but the attempt is to fake the patterns of a three-stripe damascus or fine English damascus steel barrel. In this case, the pattern is applied by using a heavy roller on the outside surface of the barrel to engrave the pattern.

In the above two examples, the forger copied the pattern off a real damascus barrel and transferred it to the barrels using a painting technique called decalcomania, which was invented originally to copy designs onto pottery. The process of decalcomania is still with us today, we only call it by its shorter name, "decal."

In all these pictures, the reader might be struck by how badly worn out these imitations are, compared to the genuine damascus steel barrels of the previous few threads. This is because of the inferior quality and workmanship of the materials. Unfortunately when these were brand new, some of these were hard to tell apart from the real thing.

Barrel Making: Pattern Welded or Damascus Barrels - III

In the previous two posts, we looked into the history and development of damascus barrels throughout the world. Now we will look at some samples of such weapons. Before reading this post, it might be worthwhile to read through the previous post to understand how these barrels were manufactured.

Single Iron or Single Stripe Damascus

The first example we see above is a double barreled gun made of what is called "single iron stub damascus" which was used for the cheapest damascus barrels. In this type, a single twisted rod is flattened into a ribbon which is twisted around in a spiral form into one barrel. Two separate single barrels were made this way and welded together to make a double barreled gun. As you can see, the pattern has swirly lines, but is not as regular as some of the following examples. The raw materials used to make this rod came from old horse-shoe nails, broken files and coach springs.

Two Iron or Two Stripe Damascus

In the above example, we see a double barreled shotgun made with what is called a "two-iron damascus" type. In this type, two twisted rods, each one twisting in a different direction, are taken and rolled into a single ribbon, which is then wound in a spiral form into a single barrel. Two such single barrels were made and then welded together at the center to form the double barreled gun. Notice the rich patterning of each barrel in the above picture and compare it with the single-iron damascus type.

Three Iron Damascus or English Damascus

The above double barreled weapon is a three-iron damascus, otherwise known as an English damascus. This one uses three twisted rods which are combined into a single ribbon, which is then wound in a spiral form to make a barrel. Note the fineness and richness in patterning compared to the ones above. This type was used for the finest English sporting guns.

Laminated Steel and Silver Steel Damascus

In the above two images, we see fine examples of laminated steel damascus and silver-steel damascus. As with the three-iron damascus, these are made with three twisted rods, but the difference is the composition of the materials used to make the rods. These two use a higher percentage of steel and a better quality of iron to make the rods. Also, in laminated steel damascus, the iron and steel plates are piled in a different order before being combined, which gives the patterns a different shape than the other examples.

Six Stripe Damascus

As mentioned in our previous post, the English did not often make ribbons using more than three twisted rods, as they determined that the pattern was fine enough and that the pattern was not significantly improved by using more twisted rods. The Belgians on the other hand, used to manufacture some barrels using six twisted rods, each of which was twisted much more than the English manufacturers (They would use 18 turns per inch, whereas no English manufacturer would exceed 8 turns per inch, when twisting the rods). This gave it a beautiful finish, but it wasn't as strong as English barrels, because the excessive twisting actually weakened the barrels a bit. An example of a six-stripe Belgian made barrel is above.

Barrel Making: Pattern Welded or Damascus Barrels - II

In our last post, we looked at some of the history behind the so-called "Damascus barrels" and the history of manufacturing barrels of this type in India since the 1500s. In this post, we will investigate more about the damascus barrels and the state of art between the 1800s and 1900s in Western Europe. The technology behind this could produce barrels that look like the following two pictures:

(Click pictures to enlarge)

As we noted in our previous post, wootz steel (the steel used in the so-called "damascus blades") was NOT used to make damascus barrels very much. William Greener in his Gunnery in 1858: Being a Treatise on Rifles, Cannon and Sporting Arms writes that these barrels are rare and on examination of the available barrels made by wootz steel workers, most were actually were made of commonest iron with a very thin plate of wootz steel around them, indicating that the wootz steel ore was becoming very valuable, since the mine in India where the ore came from was running out. Instead of using wootz steel, the more common option was to use pattern welded steel and the reason that they were called damascus barrels is because the patterns on the pattern welded steel resembled that made from wootz steel. So the name "damascus" is a misnomer and when we say "damascus barrels", we really mean "pattern welded barrels". In pattern welding, two or more metals are used to make the barrel (usually iron and steel bars, or steel bars of varying carbon content).

To study how this was done, first we start with the invention of the Puddling Furnace to prepare iron and steel bars of required carbon content. Pig iron from quality iron ore is placed in a furnace, melted and cleaned of all impurities by puddling. The impurities are generally lighter than the molten iron and hence rise to the top and can be skimmed off. Any carbon generally burns off as carbon-dioxide and bubbles out of the molten iron. When most of the impurities have been skimmed off, the iron is allowed to cool and form large balls (called blooms) about 30-38 cm. in diameter and weighing about 35-40 kg. Each ball is then grabbed with a pair of tongs and put under a tilt hammer and manipulated to make it a square shaped block. This process is called shingling, and it condenses the iron atoms (increases its density) and makes additional impurities and brittle scale fly off during the hammering process. It is then passed between several rollers, which elongate the bar and thin out its cross-section. The rolling process also increases the ductility of the iron bar. This process ends up losing approximately 40% of the material that we started with, but produces high quality iron suitable for making gun barrels.

Scrap steel is also treated the same way as the iron bars, but if new steel bars are used instead, then those low in carbon content are chosen and used directly without going through the puddling process. Steel is not improved by the puddling process like iron is.

After these, the steel and iron bars are cut to equal lengths and arranged in layers in a definite pattern and then welded together. The amount of steel to iron ratio depends on the type of pattern welding desired. The type called English Damascus is about 60% steel and Silver Steel Damascus is about 75% steel. The way the bars are arranged in layers depends on the pattern desired in the end product. The picture below shows how to arrange the iron and steel layers before welding, in order to produce a star pattern at the end:

The dark parts are steel and the light parts are iron in the above figure. In other cases, instead of using bars that are square and rectangular in cross-section, they may use rhomboidal cross-section bars, or hexagonal cross section bars etc. The pattern that is produced on the barrel at the end depends on how the bars are arranged in the stack. The above image shows how they are arranged to produce a star pattern, but there are different ways to stack the bars to produce other pattern shapes as well, some of which were only known to old-time barrel makers and are now lost. The stack is arranged with more steel than iron to produce stronger barrels. The bars are then heated and welded together into a single bar and then, it is rolled between various sets of heavy rollers to produce a longer bar. For instance, we may have 25 bars of steel and iron each 60 cm. long, 5 cm. wide and 0.6 cm. thick (or 23.5 x 1.96 x 0.23 inches). After welding and rolling, we may have a long bar which is 1 cm. square (or 0.393 inches square) in cross-section. This long bar is then cut into 120-150 cm. (48-60 inches) lengths to make it more manageable.

These bars are then heated again to red-heat about 45-60 cm. (18-24 inches) at a time and one end is put into a fixed square hole or a vice grip and the other end is put into a movable square hole or tongs and then twisted. During the twisting process, the rod is watched very carefully to make sure it twists evenly. If one side twists more than the other, a skilled worker with a pair of tongs holds that side to prevent it from twisting and evens it out. The process of heating and twisting is repeated until the whole bar is twisted evenly and this produces a uniform pattern.

After the whole bar is twisted, it will have a circular cross-section, except for the two ends held by the square holes or vice grip/tongs which will still be square. The bar will also reduce in length due to twisting. For example, a 120 cm. (48 inches) long rod before twisting will become about 100 cm. (40 inches) long after twisting and have about 32 turns per every 10 cm. (4 inches) length. The two square ends of the rod are cut off and the rod may be used to manufacture a barrel.

Depending on the quality of the barrel desired, a single twisted rod may be used, or multiple rods may be used. For instance, in cheapest damascus barrels, only a single rod is used and this is heated and flattened into a ribbon. In better quality barrels, two, three, four, six or eight rods may be used. If multiple rods are used, they are chosen so that adjacent rods are twisted left or right. The rods are then combined together and welded together and rolled into a single long ribbon. Usually, very fine patterns are obtained by using three rods, so using more rods is generally considered overkill. The diagram below shows how to combine three rods into a single long ribbon.

Note how the rods are placed so that adjacent rods twist in opposite directions. The rods are flattened into a long ribbon of a given uniform thickness.

This flat ribbon, whether formed of a single rod, or of multiple rods, is then washed in acid. The steel parts being harder, resist the acid better and retain their white color. The softer iron reacts with the acid to form a darker brown or black color. The figure below shows a ribbon after it has been washed in acid:

This flat ribbon is then coiled around a mandrel in a spiral form. This is generally done at room temperatures, but if the thickness of the ribbon is too much, then it is heated to red heat before being twisted. The image below shows the ribbon being twisted in spiral form around a mandrel to form a cylindrical barrel:

The coil is then heated and the spirals welded together by hammering. Generally three people are involved in this operation -- a skilled foreman who holds and rotates the coil with one hand on a grooved anvil and also has a small hammer on the other hand to indicate where to strike. The other two workmen carry heavier hammers and strike at the points indicated by the foreman. This forms the tube of the barrel. The hammering process is continued until the barrel cools down enough that it turns black in color, which finishes the process. This hammering improves the density and tenacity of the barrel and the wear and tear of the barrel greatly depends on performing this process properly. If polygonal barrels (such as octagonal) are desired, then the same process may be performed by using an appropriately shaped anvil.

If longer gun barrels are needed, then two or three ribbons of different thicknesses may be used. The thickest ribbon is used to form the part of the barrel that forms the breech and the thinnest ribbon is used to form the part of the barrel that is the muzzle of the gun (since the pressure of gases at the muzzle is lower than at the breech, the barrel can be thinner at the muzzle end). The ribbons are combined end-to-end to form a long ribbon and then it is hammered into the spiral form as described in the last two paragraphs.

The resulting gun barrel has a pleasing patterned look about it, such as the beautiful example pictured below:

(Click picture to enlarge)

Notice the intricate patterning on the barrel. The evenness of the pattern has to do with the quality of welding the iron and steel bars together and how evenly the twisting of the rods was done. This is clearly the work of very skilled craftsmen.

In the previous post, we'd mentioned that pattern welded barrels were being made in India since the mid 1500s. The technology gradually went west, reaching Turkey around the 1600s and then Hungary (1634), Spain (1650), Austria (in 1683), Belgium (1700), France (1750s) and eventually reaching England in the late 1700s/early 1800s. W.W. Greener, in his book, The Gun and its Development, Second Edition, mentions that pattern welded gun barrels were made in England between 1800 and 1910 or so. Around that time, the main centers of pattern welded barrel production were Birmingham and London in England; La Chafontaine, Liege and Nessonvaux in Belgium; St. Etienne in France; Vienna in Austria; Suhl in Prussia (Germany) and Brescia in Northern Italy. He also mentions that some makers in the European continent, especially in Belgium, produced some of the most beautifully figured barrels, but they were not as strong as English barrels, because they were more concerned about the pattern than the strength, whereas English manufacturers tended to put more priority on strength of the barrel and put pretty figuration lower down in importance. Some Belgian manufacturers would use up to 32 plates of iron and steel to make a single rod which would be twisted into a very fine screw thread. Six of these twisted rods would be used to make a single ribbon and the pattern on these ribbons were very fine lines, no thicker than the point on a needle. His father, William Greener, in his treatise about the Gun, mentions that while such barrels were very beautiful to look at, too much twisting is bad for iron, since it rearranges the iron fibers which normally run parallel to each other and support each other. Nevertheless, the manufacture of Damascus barrels in Belgium was cheaper than in England and by the 1850s, some English manufacturers (especially in London) were importing some of their barrels from Belgium.

By 1910 or so, pattern welded barrels were not made in England any more and all English manufacturers imported their "damascus" barrels from reputable Belgian sources. The popularity of pattern welded barrels started to wane because of stronger steel barrels produced by other methods (such as Whitworth steel) and the fact that making fine pattern welded barrels was labor-intensive and needed high skill of craftsmanship. By the start of WW-I, when Germany invaded Belgium, production of pattern welded barrels had ceased completely.

Note that while pattern welding did produce stronger barrels in the 1700s and part of the 1800s, the rise of better steel production techniques made this technology somewhat obsolete. Despite popular culture which assumes that pattern welded Japanese samurai swords can cut through anything, the truth is that even a modern spring from a car suspension has better quality steel than an authentic pattern welded Japanese sword from the 1700s/1800s. The same holds true for gun-barrels as well and modern steels far exceed pattern welded steel in hardness, toughness and durability. The extra labor and specialized skills needed to make pattern welded steel barrels also made it less desirable compared to other techniques.

Production of pattern welded barrels was restarted in the 1960s in England and gradually other countries began to produce them in small quantities. They are still made by specialized makers for custom beautiful shotguns and pistols.

Barrel Making: Pattern Welded or Damascus Barrels

In our last post about early barrel making techniques in Europe, one of the techniques we studied was the making of the Canon a Ruban type barrels in France. On reading that article and viewing the picture of that barrel, the reader cannot but note the beautiful striping pattern on the barrel showing the grain of iron. Now we will study another method of manufacturing barrels, that originated not in Europe, but in India!

First we start with something called "Damascus Steel". What is popularly known in Europe as "Damascus Steel" was really a type of steel called wootz steel that originated in Southern India around 300 BC. The crusaders originally encountered swords made of this steel in Damascus, Syria and that's how it got its name. These steels were noted for their sharpness and toughness. One of the characteristics of swords made wootz steel is a banding pattern on the blade. Thus, any sword with the characteristic banding pattern was considered to be extremely high-quality.

While the wootz steel owed its qualities to certain impurities found in the ore from a specific mine in India, another way was found to reproduce the beautiful wavy patterns on a blade.

This technique was called "Pattern Welding" and was known to several cultures indeed. The Japanese used it to manufacture their swords since 1100 AD and the Vikings and Celts were using it around 600 AD, as were the ancient Germans. The idea was to use bars of two or more types of steel (0r iron and steel), one having less carbon content than the other and forge them together into a single bar, by heating, twisting and hammering as needed and then fold the bar onto itself and hammer forge it again and repeat the process of heating, twisting, folding and hammering multiple times, resulting in a bar with layers of steel of different types. Such a bar is called a pattern welded or laminated steel bar. The multiple repeated processes of twisting, folding and hammering causes the resulting steel to be purified of impurities and form a tougher steel. The resulting steel has wavy lines and patterns visible due to the difference in chemical composition between the different bars used. An example of steel produced with this method is shown below. Note the beautiful figurations on the blade, which is characteristic of pattern welded steel:

By 1570, pattern welding was used in the manufacture of gun-barrels in India, according to the Ain-i-Akbari written by Abul Fazl, the court historian of the Mughal emperor Akbar of India. From volume 1, we have the following chapter:

ON MATCHLOCKS
"These are in particular favour with His Majesty, who stands unrivalled in their manufacture, and as a marksman. Matchlocks are now made so strong, that they do not burst, though let off when filled to the top. Formerly they could not fill them to more than a quarter. Besides, they made them with the hammer and the anvil by flattening pieces of iron, and joining the flattened edges of both sides. Some left them, from foresight, on one edge open but numerous accidents were the result, especially in the former kind, His Majesty has invented an excellent method of construction. They flatten iron, and twist it round obliquely in form of a roll, so that the folds get longer at every twist then they join the folds, not edge to edge, but so as to allow them to lie one over the other, and heat them gradually in the fire. They also take cylindrical pieces of iron, and pierce them when hot with an iron pin. Three or four of such pieces make one gun or, in the case of smaller ones, two. Guns are often made of a length of two yards those of a smaller kind are one and a quarter yards long, and go by the name of bamdnak. The gunstocks are differently made. From the practical knowledge of His Majesty, guns are now made in such a manner that they can be fired off, without a match, by a slight movement of the cock."

Around the early 1600s, the technique had spread to the Ottoman Empire and later to Hungary and Spain by the 1650s. The defeat of the Turks in the Siege of Vienna in 1683 yielded thousands of captured pattern welded barrels for examination, and this event accelerated the manufacture of pattern welded barrels in Europe. By 1700, the Belgians were producing pattern welded barrels in Liege, and in the early 1800s, the technique was used in England to produce high quality sporting barrels.

Even though making steel through pattern welding is a vastly different process than producing wootz steel, they both have similar wavy watering patterns in the final product. However, since wootz steel was becoming rarer, due to the fact that the mine in India where the special ore was mined from was running out of ore, it wasn't used to make gun barrels very much. William Greener in his Gunnery in 1858: Being a Treatise on Rifles, Cannon and Sporting Arms writes that on examination of barrels made by wootz steel workers, most were actually were made of commonest iron with a very thin plate of wootz steel around them, indicating that the wootz steel ore was becoming very valuable. In fact, when anyone refers to "damascus barrels", they are almost certainly referring to barrels made by the pattern welding method, not barrels made out of wootz steel.

We will refer to some details about the technique of pattern welding used in India, written by Lord Egerton of Tatton, from his book Indian and Oriental Arms and Armor, published in 1896. This section is reproduced from an article from that book, found on damascus-barrels.com

It is said that the Persians distinguish by ten different names the varieties of watering. One of the most prized and rare is that which takes its name from the grains of yellow sand. There are, however, four main patterns generally recognized:

1. " Kirk narduban," meaning the forty steps or rungs of the ladder, in allusion to the transverse markings of fine grey or black watering. The idea is also expressed in an inscription on one of the blades, that the undulations of the steel resemble a net across running water.

2. " Qara khorasan," nearly black, with fine undulations proceeding like water either from the point to the hilt, or the reverse way.

3. Qara Taban, " brilliant black," with larger watering and more grey in tone.

4. Sham, or simple Damascus, including all other varieties. On the introduction of the use of firearms, the methods long and perhaps exclusively known to the Asiatics, of manufacturing sword-blades of peculiar excellence, was transferred with some modification to that of gun-barrels, and are still in use.

In addition to those, Sir J.I. Burnes mentions " Akbaree," in which the pattern ran like a skein of silk the whole length of the blade, and "Beguraee," where it waved like a watered silk.

In Persia, Kabul, the Punjab, and Hind the same general principles prevail, but the matchlocks of the last are held deservedly in the highest estimation.

In some parts of India the workmen prefer for the material of their barrels the iron of old sugar boilers, but they use in Kashmir the iron of Bajaur (in the country of the Yusufzai) as it comes from the smelting furnace, after receiving a few blows whilst hot, which condense it into a rude kind of pig, the weight of which varies from five to eight seers (10 to 16 Ibs.), and which sells
as high as 4d. a pound. The first process consists in cutting the pig when heated into narrow strips with a cold chisel, and in this operation the iron loses one-fourth of its gross weight. Each of these strips separately is brought to welding heat, and worked smartly under the hammers of two men on a block of limestone as an anvil. When the slag is expelled, each strip is drawn out by the hammer into a strap about 2 feet long and 11/5 inch broad, and 1/5th inch thick. One of these straps has its ends so brought together as to enable it to include about 20 other short straps cut up for the purpose, some being placed on their edge, and others wedged in between the lengths, sо as to form a compact mass. It is then put into the fire and lightly heated, receiving a few blows upon both faces as well as upon the edges.

It is next smeared over with a paste of clay and water, and when dried it is exposed first to a light welding heat, and after a slight hammering to a stronger heat, when it is vigorously and quickly beaten into four-sided bars about a foot long, and a finger's thickness. These are again heated, separated, and drawn out into square rods about J-inch broad on each face. These are then twisted from right to left, while the part which is to be twisted is heated to a red heat nearly verging upon white. This process is repeated by heating two or three inches at a time, and then cooling it with cold water, till the whole rod is converted into a fine screw, which is made as even as possible.

To make an Iran barrel six or eight rods are required. When eight are employed, four of them have the twist from right to left, and four from left to right. Every rod after having been slightly heated is lightly hammered on its two opposite sides equally, so that two sides have the threads beaten down, and the two others have the threads standing, and retaining their original roundness. Each rod is now made up of lengths of the same direction of twist, and is laid parallel to the other, so that rods of opposite twist are in alternate succession.

The steel having been formed into bars is now ready for manufacture into gun-barrels.

The extremities of the bars are welded together, and the baud or skelp is now ready for being formed into a hollow cylinder through being twisted in a spiral line upon itself, which is begun at the breech or thicker end, and continued to the muzzle. When the twisting is so far completed that the edges of all the twists stand even, and the cylinder is nearly equal, it is coated with a thin paste of clay and water, and is then ready for being welded.

A welding heat is first taken in the middle of the cylinder, and the edges of the twists are brought together by the breech being struck down upon the stone anvil perpendicularly for the purpose of jumping up the edges. The welding is constantly repeated, so that the twist, which was jumped up, is successively hammered when the heat is well on, till the barrel has been
welded up to the muzzle.

This process is then repeated, commencing from the middle to the breech, and afterwards from the middle to the muzzle, during which an iron rod is introduced at each end and used as a mandrel. A third heat nearly red is now taken at the whole surface of the barrel, which is then made regular and level by smartly hammering it. The barrel is then fixed horizontally through
a hole in an upright post and bored, after which its surface is filed, polished, and prepared for bringing out the damasked lines. " Jauhar " is brought out through biting the whole surface with " kasis," a sulphate of iron.

The barrel is completely freed from grease or oil by being well rubbed with dry ashes and a clean rag. About three drachms of sulphate of iron in powder is mixed with as much water as is sufficient to bring it to the consistence of thick paste which is smeared equally over the whole surface of the barrel, the muzzle and breech being at the same time carefully plugged. About two hours afterwards, when the metal has assumed a blackish colour, the coating is rubbed off, and the barrel cleaned as before. Barrels are called " pechdar" when plain or simply twisted, "jnulmrdar tvheu dunmsked" when damasked. For the latter the rods are disposed according to the kind of brilliant or damasked lines to be produced, called either from the country as "Iran" or Persian, or from the figure, as " pigeon's eye," " lover's knot," " chain".

The barrel is then smeared with a preparation composed of the same quantity of sulphate of iron and four ounces of water, and is hung up in the well. Every gunsmith has, in the floor of his shop, a well about two yards deep, the bottom of which is covered with a layer of fresh horse-dung half a yard thick. Suspended by a string from the cross stick at the mouth of the well, the barrel which has been covered with the mixture as before is taken out every morning and cleaned with dry ashes and cloth, and hung up for 24 hours with a coating of the solution. This process is continued for 20 days or a month till prominent lines are formed on the surface of the barrel, separated from each other more or less by other depressed lines or grooves; the former will be found to have the same direction as that of the thread of the screw in the twisted rods. The prominent lines when rubbed are bright and of a colour somewhat approaching silver, while the depressed lines are dark and form the pattern.

The " zanjir " or chain damask consists in the introduction of a band of prominent and brilliant lines disposed like the links of a chain between parallel plain lines of damask. The processes are the same as before described in cutting up the " pig," and in reducing the strips into straps, but the " pie " or " ghilaf " contains only eight lengths, which when welded is drawn out into straps 1/2 inch broad and 1/8 inch thick. One of these straps being heated is bent backwards and forwards upon itself in eight continued loops, each an inch long, and is then worked up into straps 1/3 inch broad, and 1/16 inch thick.

Three of this kind of strap are required in this pattern, one for the chain and two for the lines. The face of the iron anvil has a perpendicular hollow about one-quarter of an inch deep, and about one-third of an inch across. One end of the strap is laid while cold across this groove, and driven down into it by a small chisel and hammer, by which the strap receives a bend or angle. Its opposite face is then placed across the die near the acute elbow made by the chisel, and is in like manner wedged into it, after which the operation is reversed until the whole band is converted into a frill of loops. This frill is then heated, and the operator holding one end with a small pair of tongs brings two pairs of loops together leaving the ends open. This is continued till the frill is much reduced in length through the loops of the strap standing at right angles to its general direction. Different lengths of frill are welded together, so as to form a ribbon six spans long, placed in contact with two plain straps set on edge, and four rods, two on each side
twisting alternately, from left to right, and the reverse. The general band of these seven straps is then treated as that for the "Irani" damask.

The chain damask is in general preferred to all other varieties, excepting the silver twist. The Kashmiris still make blades for daggers in the same way, as one which was made for the author at Srinagar to fit an Indian jade handle is damasked, and Moorcroft relates that they made sword blades for him to order, though they did not usually manufacture them. It is said that "jauhar" is imitated in Hindustan by lines being traced in a coating of wax laid over the metal, and the barrel being exposed to the action of sulphate of iron.

We will now look at some pictures of barrels produced in India using such techniques. The first is an Indian matchlock with a herringbone pattern barrel:

(click image to enlarge)

The next is an Indian matchlock from the late 1700s with a beautiful Crolle-twist wave pattern:

(click image to enlarge)

The next is an 18th century Indian musket with a laminated steel barrel:

(click image to enlarge)

Note that while the barrel making technique in India was quite advanced in the 1570s, they were still using ancient matchlock firing mechanisms by the time Lord Egerton wrote his book in the late 1800s. In the next post, we will look at the manufacture of pattern welded barrels in Europe.

Barrel Making: Early Barrel Making in Europe

In our last post, we talked a bit about the gunmaker guilds and how they affected gun development in Europe. We also talked about how the early barrel makers were blacksmiths. We will visit some of their history in this post.

The blacksmiths of Italy and Spain that made the early gunbarrels usually used iron from old horse-shoe nails. There was no specific reason to prefer iron from horse-shoe nails, merely that a majority of the early barrel-makers just happened to be the same blacksmiths that dealt with making horse shoes and fitting them. In modern times, a person specializing in making and fitting horses shoes is called a farrier, but in the middle ages, the job of the farrier and the blacksmith were practically synonymous and the terms were used interchangeably.

The method used in Spain was to weld a bunch of nails into a strip of iron and then bend this into a cylinder about 5-6 inches in length. The strip is curled around itself twice so that the walls are double throughout the cylinder, for extra strength. To form a barrel of a certain length, multiple cylinders are selected and arranged end to end and welded together to form the barrel. The advantages of this method are that the metal is forged in smaller sections, so it is better wrought and purified. Also, if one of the cylinders has cracks or weld defects during its forging process, it can simply be discarded and another one substituted in place, when joining all the cylinders together to make a new barrel.

When this method was used, there were a lot of metal loss during the forging process. About 20 kg. of nails were used to make a barrel that weighed just 2.5-3 kg., but the resulting barrel was light and strong. Martinez del Espinar, the personal gun-bearer of King Philip IV of Spain, mentions that a quality gun barrel 1 metre long that is forged with this method should weigh just 2 kg. Making these barrels was labor intensive and expensive and hence this technique was used to manufacture barrels for the finest sporting guns of that period.

Another method of barrel manufacturing also became popular in France in the late 1700s. Barrels produced by this method were called Canon a Ruban or "Ribbon barrel". The method of manufacture, as stated by Marolles is as follows:

First, the smith starts off with a sheet of iron that is much thinner than the required barrel. This sheet is rolled into a thin tube that is the length of the barrel and slightly smaller than the required barrel diameter. This tube is called a chemise. Then a thicker strip of iron about an inch broad and chamfered to a point on either edge is heated a few inches at a time and wound around the chemise. This strip is called a ruban (i.e.) a "ribbon". To roll it around the chemise, they use a pair of tongs where one beak is short and flat and the other is rounded and long. The long beak is used to turn and press the strip on to the chemise. Five feet of ruban is used to make one foot of barrel. Since it is hard to make a barrel from a single ruban, the smith often made three of these separately, each one foot long, and then welded them together into a single three-foot long barrel. Then the whole barrel is placed in the furnace to heat it and forge it as a single barrel. Then the barrel is sent to the boring shop, where the chemise (the lining) is mostly removed using a boring bit, leaving behind the ruban forming the barrel.

This method produced a barrel of superior strength, as the welds were transverse to the barrel and could better resist the force of explosion. An example of a double barrel muzzle-loading weapon produced with this method is shown below:

(click image to enlarge)

Note that a part of the "CANON A RUBAN" inscription is visible, engraved between the two barrels, showing that these barrels was made using the above method. Also note the striping on the barrel showing the grain of the ribbon twisted around the chemise. The barrels have a beautiful appearance with figured patterns and have also been browned to protect them from rusting. The process of "browning" will be described later.

Another method that became popular in the early 1800s in Birmingham, was to roll a thick barrel out of a short strip of iron wound round a mandrel. The mandrel was then removed and this barrel would be passed between rollers with tapered grooves to lengthen the barrel, the edges being welded as the barrel passed through the rolls. This method of manufacture was severely opposed by the welding workers associations, as they saw it as a threat to their livelihood. Even though there were several riots, this method was used by several manufacturers because of its suitability for mass production of musket barrels. Muskets made using this method were often low-quality and many were exported to Africa as part of the slave-trade.

Barrel Making: Early Gun Making in Europe

In the last post, we studied the early history of barrel making and different techniques that were used to make early gun barrels. In Europe, the first barrels were made in Italy, probably by smiths in Perugia. At this time, medieval Europe was beginning to see the rise of guilds which were associations of workers of a particular trade. People who were not guild members were not allowed to practice the profession of the guild in question. There were guilds for various professions such as tailors, wine makers, weavers, blacksmiths, carpenters etc. and each guild would guard the secrets of their profession jealously. Accordingly, it was the blacksmiths guilds that had a monopoly of the early gun trade in continental Europe. The centers of gun production were either state owned arsenals such as St. Etienne in France, Brescia in Italy, London in England etc., or in areas where smith guilds were concentrated (in particular, people who made iron nails) such as Liege in Belgium, Suhl in Germany, Bilboa and Eibar in Spain etc. After the early muskets were made, blacksmiths often had to work in collaboration with the carpenters guilds to make the wooden stocks that the barrels were mounted to. This led to craftsmen in some regions forming their own unique "gunmakers guild" which was then regarded as a separate profession from the normal blacksmith and carpenter guilds. The gunsmiths of Suhl formed their guild in 1463.

England was relatively late in the gun-making game and at the time when Henry VIII ascended the throne of England in 1509, there were very few guns in England's arsenal and there was only one expert cannon maker in all of England who knew how to cast guns. Henry VIII quickly rectified the gun shortage situation by importing every gun he could buy from continental Europe and built up a sizeable arsenal very quickly. In fact, by 1513, just before a war with France, Henry placed a large order of guns with the kingdom of Venice and caused the outraged Ambassador of Venice to report back to the Doge that he already had "enough cannon to conquer hell!"

Due to the monopoly of the local guilds throughout continental Europe, many who had learned the profession could no longer practice it if they moved from one town to another, since they were not members of the gunmakers guild of the new town. Luckily for England, the guilds did not have as much power there and so when Henry VIII invited skilled gunmakers to settle in England and carry their trade there, many were only too glad to accept. Arcanus de Arcanis from Italy, Peter van Collen from Belgium, Bawde from France, Cornelius Johnson from Holland and several other skilled gunmakers of that era all made their way to London. By 1545, Henry VIII had plenty of people in his service who knew how to use, repair and make arquebuses. Along with setting them up around the Tower of London (where England's Royal Arsenal was situated), Henry requested that they train local Englishmen in their trade as well. These gunmakers were the start of the gun-making industry in England and for the next few hundred years, the industry was concentrated around the neighborhood of the Tower of London. By the time Henry's daughter, Queen Elizabeth I, ascended the throne, there was thirty-seven gunmakers plying their trade and a Dutchman named Hendricke was the most famous gunsmith in the 1590s. However, King James repealed an act of Queen Mary and granted the monopoly of gunmaking to one Edmund Nicholson and the industry declined to the point that, by 1607, there were only five gunmakers left and they petitioned Parliament to abolish the monopoly so that the "mysteries of gunmaking could be retained." Their grievance was addressed, but it wasn't until 1637 that the London Gunmakers Company was established and this guild later began to dominate England's firearm industry to the detriment of other centers of manufacturing. In fact, there were several legal battles between the members of the London Gunmakers Company and the Birmingham Gunmakers Company in the years to come.

Barrel Making: Early History

We've just finished studying rifling technology in the last 14 posts. Now it might be a good idea to study barrel-making, i.e. the part that the rifling is cut into.

Let's start with the basics... why is a "barrel" called that anyway? To answer that, we have to go to the early days of making barrels. Back in the 1300s and 1400s, metallurgy was not as advanced as it is today, and neither were machining techniques. It was too time consuming to try and drill a hole through a solid cylinder of iron or bronze. So they had to use one or two different techniques to make barrels.

The first inventors of gunpowder were the Chinese and they used bamboo plants as their barrels. Bamboo tree trunks have naturally cylindrical hollow tubes and were plentiful in China as well, so it was natural to use these for small hand-cannons. The main problem with bamboo is that it can't take a lot of pressure, so the early hand-cannons could not fire powerful charges. Another alternative was to wrap the bamboo tubes tightly with rope to strengthen them.

The next technique to be used was casting. One of the oldest types of casting is called Green sand molding. First, a model (called a "pattern") of the barrel tube is made using an easily machined material such as wax or clay. Then the pattern is placed in hollow box frames (called "flasks") with no top or bottom. A couple of cylinders (called the "runner" and riser") are also placed in the box, touching the pattern. Wet green sand is poured into the flask and packed tightly around the pattern, the runner and the riser. After this, the runner, riser and pattern are removed, leaving hollows in the sand. Molten metal is then poured through the hole left by the runner tube and flows into the cavity left behind by the pattern and climbs up the riser. The metal is left to cool and harden and then the sand mold is broken to reveal the hardened casting. In another type of casting called "investment casting" or "lost wax casting", the pattern is not removed, but when molten metal is poured into the runner tube, it melts the wax and pushes it out via the riser tube. Incidentally, the "lost wax" casting method traces its history to India, centuries before guns were invented. Ancient Indians used this technique to make metal figurines and intricate jewelry. The Chinese were the first to employ casting techniques to make metal gun barrels and Arabs and Europeans also used this technique later. Cannon and gun barrels of cast-iron, bronze and brass were made using this method. It must be noted that casting technology was not fully developed and one of the major problems was that air bubbles trapped within the molten metal would leave hollows and cracks in the final product. To compensate for this, early gun barrels were made with very thick walls.

The next technique originated in Europe in the first half of the 14th century. In this method, the smith first makes a cylindrical pattern out of wood or clay, which is of the diameter and length desired. Next, the smith forges a number of iron bars of almost rectangular cross section and the same length as the pattern. These bars are fitted around the pattern as closely as possible, so there are no gaps between them. The pattern is then pushed out from the center, leaving the bars holding each other in place in the form of a tube. Then the smith forges a number of iron rings or hoops, whose diameter is slightly smaller than the diameter of the tube. The smith then heats these rings until they are white hot, which causes them to expand and they can be easily slipped around the iron bars. The rings cool and then contract, holding the metal bars in place.

For smaller pieces, instead of using bars of iron, the smith takes a flat rectangular iron sheet and bends it into a cylindrical tube and welds the long edge from end to end. Then he strengthens this tube by adding the metal hoops along the length of the tube, using the same technique explained above.

This technique of using straight staves and holding them in place with hoops was not a new idea. It was actually used centuries earlier for making wooden barrels to hold liquids. Hence, the name "barrel" also transferred to gun "barrels". This is true not only in the English language -- many other European languages also use the same words for "barrel" when referring to the wooden containers and the gun barrels.

So that's how the word "barrel" came to be used for guns as well.