The subject may be understood by the following observations. All tapering substances, when laid together were the taper extended, would come to a point at a certain distance. Gun-barrels are made to taper towards each other, and some more than others. To make them uniform, it requires that they should be reduced or flattened, so that the thick or heavy end should join closer, to allow the point of convergence to be extended to a greater distance. If, then, we take two barrels two feet eight inches long, and having a solid substance of metal at the breech of 3-16ths of an inch each and 1-16th at the muzzle; it requires the difference 4-16ths to be multiplied 45 times (there being that number of lengths in 40 yards) to ascertain what distance the points of the different lines are from each other: which will be eleven 4-16ths of an inch, or five 10-16th inches from the centre or line of sight. If you wish to reduce it from the centre, you have to join the barrels so much nearer at the breech; or should the inclination be too little, the muzzle must be jointed closer. As, however, all guns are now made very heavy at the breech, they very seldom require any closing at the muzzle: though it is customary to do it, and to a great extent; but it is owing to the ignorance of the nature of shooting.
Different lengths require a difference in the height of the rib. A greater height is also required for a person accustomed to use a crooked stock, and less height for one accustomed to the use of a straighter one; and so on. Few barrels are to be met with in which the elevation is sufficient. This is a species of innovation much practised by gunmakers of the present day; but whatever merit there may have been in the original invention, there is none in “the improvement,” as they term it. Take any of the modern barrels, and calculate what is the real elevation of them, and you will find it is not equal to the distance that charges will droop at forty yards, when we consider the very large charges of shot that many are accustomed to use, without a corresponding quantity of powder. It remains then to be decided what elevation a gun should have for that distance.
I have tried the experiment some hundreds of times with guns of all descriptions, both with a rest and from the shoulder, and standing as firm as possible; by turning quickly round, and firing (as we might do were a bird to spring in a situation where we could only get a snap shot) against targets such as are used in military ball-practice, being about six feet high, and by means of which one can perceive where the body of the shot had struck. I have also fired against the steep sides of sand-banks, on which, from their smoothness, you can tell every shot that has struck them. My conviction is, that almost all guns charged (as is the custom) with heavy charges of shot, droop full twelve inches in forty yards; though by using small charges of shot you will find them to be thrown much more correctly than the heavy charges; so that it is possible to make a gun too high on the rib for a shooter who thinks more powder and less lead preferable to much lead and little powder.
The elevation I have given will be found to be as near what is requisite as possible, if we continue to load as heretofore; if reduced charges of shot be adopted, a less elevation will suffice. To ascertain what elevation at the breech for the above scale is requisite, take the thickness of the breech and muzzle, and multiply the difference by as many times as there are lengths of your barrels in the forty yards, and you will then ascertain what elevation they give of themselves; and to make up the difference wanted, must be the elevation of the rib, which may be calculated in the same way as the barrels; the length of the barrels being the only way of obtaining a correct idea of the height required. If making woodcock guns, less elevation is required, the distance of shooting being shorter. In large guns a greater elevation is necessary. We believe, however, Colonel Hawker has fallen into an error, when he says that long guns require a greater elevation than short ones. Does not a long gun keep the shot more together? Is not more force generated? and is not the initial velocity greater than in a short gun? If these be facts, why is more elevation required if the shot do not droop? We apprehend the Colonel means, if the same height be required to be given above the mark. Nothing can be plainer than this—that if one pair of barrels be four inches longer than another, and the elevation the same, there cannot be as many lengths in the forty yards of the longer barrels as of the shorter, and hence the difference when multiplied. I think, therefore, he cannot have taken into consideration the superiority in their shooting; for there cannot be a doubt that, if a gun keep the shot together longer, it cannot require that allowance for drooping which a shorter gun does.
As soon as the barrels are properly jointed; care must be taken to see that they are perfectly level. If the barrels are not level, it will be impossible to shoot correctly, as one barrel will throw the shot above, the other below the mark. This being done, the barrels are bound together and brazed with hard solder or brass, for about four or five inches. Greater injury cannot be done to barrels than by this pernicious practice; for they cannot be brazed without being heated to a white heat; and by this heat all the advantages derived from hammering are dissipated at once: the condensation is gone, and the strength is reduced at least 121⁄2 per cent. And for what purpose? Under the pretence that the barrels are firmer and not so liable to become loose. This is a point trivial in importance compared to the excellence and strength of the barrel; for even if they have received no more hammering than is necessary in the forging, they are still injured to the extent of 121⁄2 per cent.: for even beating them when hot improves them much, provided they be not heated again; but if they have been cold hammered, the injury is full 30 per cent. This circumstance shows how little the principles of gun-making are understood by the first gun-makers, the brazing of barrels being practised by all.
Mr. Wilkinson admits this, for he says—“The practice of brazing the barrels is decidedly injurious, by softening that part more than the other; but if they were only soft soldered, the inconvenience would be far greater, as the barrels would be liable to some accident by the repeated expansion and contraction that takes place in firing, as well as by the force required to turn out the breechings.” I can only say that I have had considerably more than five thousand pairs of barrels made and put together with soft solder only, and not one pair has come asunder from any of the causes mentioned; nor ever will, with fair play. On the contrary, barrels brazed can never be sound; for at some distance from the part heated for brazing, you cannot get the barrels re-tinned effectually, and thus for a considerable space between the soft and hard solder, there is no cohesion at all. Barrels brazed together only for three or four inches at the breech-end, can never be sound: they almost invariably become so rusted under the rib, in a few years, as both to seriously injure the barrels, and force the rib upwards; therefore, if you hard solder at all, do so from breech to muzzle, as that will be preferable to partially doing it. I feel quite satisfied, and can prove it to demonstration, that this is undoubtedly the most injurious process to which iron can be subjected; and I believe the prejudice with which the London barrel-makers stick to this practice is productive of considerable injury to them: more especially when we recollect that they are the advocates (in practice) of a very inferior quality of Damascus barrels: an iron very susceptible of injury. The Belgian barrels, and French also, are of good iron; and I fear not contradiction in asserting their inferiority to English barrels mostly consists in the foolish practice of brazing them together from end to end. Both chemically and mechanically it is a practice for which no valid excuse can be offered.
All barrels should have solid ribs for at least eight inches from the breech: they tend to lessen the vibration of recoil, as well as to render the barrels more sound and firm. No maker either understands science or studies quality, who advocates brazing and hollow ribs.
The invention of the patent breech was the emanation of a scientific mind; for it has been productive of more real benefit to the progress of gunnery than any other improvement of the last two centuries. Experience and study in the theory of guns and gunpowder, give the mind a much more enlarged view of the subject, if regulated by the established laws of true and sound principles: a want of thorough knowledge induces the individual to draw conclusions prematurely, and thus he is apt to fall, and to lead others, into error. I confess, that, together with many hundreds more, I once concluded that the great advantage of the patent breech arose entirely from the loose state in which the powder was preserved while in the breech, and its thus being more instantaneously ignited. But I have already shown that the quickness of powder is, in a great measure, the greatest drawback to its efficacy, and I am clearly convinced that compression, in most instances, is beneficial, by retarding the ignition to a certain extent. Here, then, is proof positive, that we have been on the wrong scent, and running after a “Will o’ the Wisp.”
