Chapter II: Construction of Shotguns

In treating briefly of shotgun construction I shall make no pretense of posing as an expert in their manufacture. There are many things connected with the building of guns about which our manufacturers talk with reluctance, such as the prices paid for raw material, wages given to workmen, actual cost of turning out a gun of a certain grade, amount of hand work placed on any particular arm, and other things. All this would be of little value to the amateur if known and might possibly embarrass the factory owners. My only endeavor here will be to give the novice an idea of how guns are constructed sufficiently clear to permit him to judge with fair accuracy his own arm or any that falls under his observation.

Barrels being a prime factor in gun building, we may as well begin with them.

BARRELS

(Damascus, Twist, Laminated, Compressed Steel.)

Up to a decade or so ago shotgun barrels were made of a combination of iron and steel strips, welded together and then twisted around a mandrel of such size as roughly to give the diameter of the bore. After being twisted into a spiral tube this was hammered or welded into a homogeneous mass. These tubes were known as twist, laminated, or damascus, depending upon the manner of using the steel and iron. The damascus barrels were further subdivided into two-stripe, three-stripe, and four-stripe damascus, the numerals having reference to the number of strips of iron and steel that were welded together before being twisted.

It is an old story that in the original, handforged barrels horseshoe nails were used, and it was popularly believed that they made the strongest and toughest barrels. Perhaps such material really entered into the construction of gun barrels, but it is not worth while to attempt either to prove or disprove the tale now.

Damascus barrels were in high favor twenty years ago. They were very tough and elastic, capable of expanding under pressure without disrupting. The only fault to be found with them is that they are soft, denting easily, when struck against another barrel or any hard object. Frequently gunners injured one another’s damascus tubes by jostling as they walked side by side.

As compared with modern fluid steel barrels those of damascus were also more liable to be injured by the gases of nitro powder, and generally they were hard to keep free from pits and rust. It is doubtful, too, if they would take as high a degree of polish as those of our present plain steel. It is the belief of the writer that except for the regard of the conservative for what was known to be good, no damascus or twist barrels would now be in use.

COMPRESSED STEEL

The plain rolled or drawn steel barrels are known to be harder than any heretofore used, thus being less liable to accidental injury. They will sustain a higher internal or chamber pressure than damascus, and are therefore better adapted to nitro powders with the occasional high pressure that may be developed by handloaded or experimental charges. Such tubes will take a higher polish, and can be kept free of pits with half the labor occasioned by the old combinations of steel and iron. The process of manufacture is simpler, and good barrels can be turned out at a much reduced cost. The choke of a steel barrel can never be shot out and will retain its pattern for all time.

Our manufacturers have various technical names to describe their different grades of steel barrels. The Krupp and Whitworth tubes, made in Germany and England respectively, have perhaps the greatest repute. Other grades of steel such as armor, nitro, high-pressure, titanic, homo-tensile, vulcan, mean nothing to the outsider more than that they are known to be placed upon certain grades of weapons by reliable manufacturers. Probably there is quite a difference in the pressure that the cheaper and the higher grades of compressed steel will sustain, but in its finished state the ordinary observer cannot detect any difference in the appearance of the grades as he could with the damascus and thus must rely solely upon the manufacturer’s word and reputation for the quality of his gun barrels.

While I should have absolute confidence in the safety of any barrel placed upon an arm by a reputable manufacturer, yet it is to be regretted that builders regard as “trade secrets” the different pressures that various grades of steel will bear. It might be well for a man to know just how close he was coming to the danger line in shooting heavy loads.

Some gunmakers advertise their barrels as being able to withstand a pressure of one hundred thousand pounds to the square inch, but it is difficult to understand just what this means. If the barrel would bear an inside pressure of a hundred thousand pounds, it would, indeed, be a corker. The ordinary shotgun charge only develops a pressure of from four to six thousand pounds, and the barrel is “proved” in the rough with a pressure of from four to five tons.

In this country we have no government proof house such as all European countries possess, and hence must rely upon the tubes being privately proved by the different manufacturers.

Strangely enough, while we turn out more shotguns than all the remaining world put together, we are not and never have been a barrel-making nation. Just why this should be true I am unable to state, but the majority of our tubes are imported from Europe in a rough form and are then put together, filed, shaped, and bored in this country. It appears only a question of a short time now when America will forge her own barrels. The Stevens people are now making all the tubes used in their factory, and the Winchester and Remington factories those adapted to their repeating shotguns.

The fluid or plain steel barrels are manufactured from a solid bar. This is first drilled through and then rolled or drawn into length or shape; after which it is rough bored into a size some thousandths of an inch smaller inside diameter than it will be when finished. It is then subjected to its first proof test which is expected to develop a pressure some three times as high as the tube will be called upon to bear with standard loads. This first test is cut upon the barrel in the shape of a “proof mark,” and it is then in shape to be exported. Should the barrel be finished in Europe, it will be given a final government proof in its finished condition, this proof developing double the bursting strain of normal charges.

In this country, having no government proofhouse, we must rely, first, upon the foreign proof-marks, and, second, upon the reliability of our builders. The foreign proof mark is practically worthless, for the reason that the barrel is afterwards filed down and shaped, and if this is unskilfully done a barrel that had ample strength in the rough might be so weakened as to become absolutely dangerous. Within the past few years I have seen a barrel burst that was as thin at the point where it disrupted as the paper upon which this is written. It follows that our only reliance is upon the integrity of our manufacturers, and ordinary precaution would require that we purchase an arm only from men who have a reputation to jeopardize.

It is greatly to our manufacturers’ credit that their output has always been of such quality that there has been little demand for a government proofhouse. Doubtless, though, should we ever become a large exporting nation, which seems probable, such an institution will have to come.

FINISHING BARRELS

The rough tube as it comes from the maker has little resemblance to a finished shotgun barrel. A large amount of skilled labor and the services of a number of special artisans are required before the tube is ready to burn nitro powder and drive shot. The barrels must first be filed down and dressed into the shape that gives them that elegant taper from breech to muzzle, and while cutting away, reducing weight and shaping them the greatest care is taken to do the work scientifically, leaving a thickness of metal where the greatest strain is to come, the whole work being accomplished by a man whose sole duty or trade is to do that very thing.

Then another expert puts the barrels together, and upon his skill depends the accurate shooting of the barrels, that is their shooting to center. I can well remember the dismay of a young friend of mine who discovered after a year’s use of the weapon that one barrel shot six inches lower than the other at twenty-five yards. Of course he no longer had any confidence in that gun, nor had he any difficulty in accounting for every miss made during all of the year.

GUN BORING AND POLISHING

Some of our shotgun borers have international reputations, and certainly they have made greater advances in their profession than have the artisans engaged in any other branch of gun building. It is said that the most skilled of these men can regularly cut a barrel to a thousandth of an inch at any point from breech to muzzle, guaranteeing a pattern within a very few pellets of that demanded. Not every shotgun barrel is cut alike, indeed every gunborer has a system of his own that will differ at least in minor particulars from those of all others, but results are practically similar. It is true that nearly all the above work is accomplished by machinery, but it is machinery that requires very intelligent supervision.

When the barrels are bored the polishing process begins, and upon the manner in which this is accomplished depends the interior beauty of the tube and to some extent its future usefulness and life. A highly polished bore is perhaps the best of all guarantees against pitting and rusting. Moreover, this polish is strictly necessary in order to guard against the piece leading at every discharge. I have seen barrels that would begin to lead with the first shot and steadily increase the deposits until from a seventy per cent. tube the pattern was reduced to one of fifty per cent. Of course faulty ammunition might have something to do with this, but it remains that some barrels lead much more than others with the same ammunition.

Leading a gun seems to be a necessary evil, not to be entirely obviated by the most conscientious work. Possibly one system of boring may show better results in this respect than another, though I have never yet seen a barrel that would not show traces of lead if shot rapidly enough to heat. It is a very disagreeable fault, rendering the piece hard to clean and causing pits where the tube is neglected, as well as reducing the pattern as mentioned. In fact, I have yet to see a gun that would maintain its seventy per cent. pattern throughout a day’s shooting.

Perhaps the cone has as much to do with the leading of a barrel as any other feature of the bore. The cone is the place where the barrel narrows from the shell chamber to its true bore. Should this be of faulty shape it may cause the charge to upset as it enters the barrel, leaving a deposit of lead at the breech. When the shot have jammed and leaded in entering the barrel they are in good condition to make further deposits; as a consequence the piece that leads in front of the shell chamber will nearly always do so in the choke as well.

BARREL FITTING

Our barrels are now fitted to their action, and here the work can by no means be slighted without betraying its slovenly character even to the novice. Barrels perfectly fitted to the frame are sufficient evidence that no part of the work of the entire arm has been neglected. Where steel and iron come together the fitting should be as fine as the edge of the sharpest tool, so close that eye can scarcely observe the joint. An expert judges the arm from the way it is fitted as accurately as a naturalist can pronounce upon the character of an animal from its teeth and jaw. If the tyro can observe any evidence of imperfect fitting then it is a cheap gun, no matter by whom made or at what price.

COST OF BARRELS--ROUGH AND FINISHED

Barrels cost in the rough as imported from two to twenty-five dollars a pair. When finished and adjusted to the frame they range in price from ten to two hundred and fifty dollars. Usually our builders charge one-half the price of the arm for an extra pair of barrels of a grade similar to that of the gun. Many of the manufacturers refuse to cross their grades by placing cheap barrels upon a high grade arm or vice versa.