Gunmetal

“ It is necessary that I can rely upon getting a pure copper and tin alloy, in the proportion known as gun-metal, on account of its strength, its rigidity, and its wearing qualities. The latter is of especial importance, because the governor joints are in continual motion under the weight of the heavy counterpoise. Experience shows that this purity cannot be relied upon where it is possible that any inferior metal can become mixed with this alloy in even the smallest proportion. This for us, not [216] making our own castings, must be wholly a matter of confidence. ”

“ Whether for speculum metal, bronze, or gun-metal, the metals must be mixed exactly, and for this purpose be kept a long time in fusion, and constantly stirred; otherwise, the alloy will not be of a uniform quality, as the greater part of [200] the copper will sink to the bottom, and the greater part of the tin rise to the surface. When we speak of brass guns, as that name is generally applied to them, we are to understand, that they are not made, like brass, of an alloy of copper and zinc. ”

“ A great emergency acts upon different men as chemical processes act upon different metals. Some it melts like lead, so that their resolution softens and runs away from them; and some it hardens to tempered steel. There was the old major now. Always before this he had seemed to me to be but pot metal and putty, and here, poised, alert, ready—a wire-drawn, hard-hammered Damascus blade of a man—all changed and transformed and glorified, he was coming down on Dave Dancy, finger on trigger, thumb on hammer, eye on target, dominating the whole scene. ”

“ The body of the gun is cast in a chill mould, by which the cooling is so rapid that the mechanical mixture of tin and copper has no opportunity of separating and forming tin spots as is the case with ordinary bronze castings. After boring the gun, a succession of steel mandrels is driven through the bore, putting the whole casing in a condition of extreme tension on the exterior and compression on the interior, so that the different strata of metal are in proper condition for resisting tangential strains. ”

“ A short, thick, hollow cylinder being cast, may be at once rolled out direct between rollers into a musket or rifle barrel of any desired form; and great guns may be cast hollow, and put under the operation of a tilt or steam hammer, if needed, to consolidate the metal. And these malleable iron guns can be procured at one-third the cost of the ordinary cast-iron guns; and, what is very important, the malleable steel is even cheaper in cost than the malleable iron. ”

“ Metallurgical science had made great progress, but cast iron was still the only metal considered suitable for large guns, whilst bronze was used for field guns. Many accidents, due to defects developing during practice, had, however, occurred, in order to prevent which experimental guns constructed of stronger material such as forged iron and steel had been made. Some of these weapons were merely massive solid blocks, with a hole bored in for the bore, and only withstood a few rounds before bursting. ”

“ Brass guns are invariably lighter, and considered less likely to burst. Gun metal, technically so called, is a compound of copper and tin, in the proportion of five, eight, and ten pounds of the latter to 100 pounds of the former. The peculiar property of the tin is to give hardness and solidity to the mass. The greater proportions are used principally for mortars, as they [62] require a greater degree of hardness than other guns. ”

“ Their antipathy to the metal furnishes men with a weapon which may be turned against the spirits when occasion serves. As their dislike of iron is supposed to be so great that they will not approach persons and things protected by the obnoxious metal, iron may obviously be employed as a charm for banning ghosts and other dangerous spirits. And often it is so used. Thus in the Highlands of Scotland the great safeguard against the elfin race is iron, or, better yet, steel. The metal in any form, whether as a sword, a knife, a gun-barrel, or what not, is all-powerful for this purpose. ”

“ The result is a metal equal in elasticity and tensile strength to the best English steel, the excellent quality of which is largely due to “oil tempering,” a process entirely omitted in the Krupp gun. The ingots forming the different parts of the gun are cast in cylindrical iron molds, an operation requiring the greatest care to prevent the imprisonment of air or other gases in the casting,—a defect which the tenacious character of the metal renders fatal. Subsequent hammering only increases the trouble by involving a larger area. ”

“ ON WORKING IN SILVER, COPPER AND BRASS.
To Forge Silver.—The gunsmith will not have much to do with silver in the work of his trade, though instances may occur now and then when he will be called upon to make or repair mountings or ornaments for gun-stocks formed of this metal, and also foresights, particularly for the old fashioned Kentucky rifle.
In shaping silver under the hammer no heat will be necessary at the hammering—it would do no good. The metal is so malleable that it may be drawn into almost any shape by simply hammering cold. ”

“ After the explosive preparation is ready for use, the smallest portion explodes when struck on an anvil with a hammer, like fulminating-powder; when kindled with a glowing body, it takes fire just like gunpowder; and, when used in a gun, its operation, though in a far greater proportion to its weight, is similar to that of gunpowder. Gun cotton is employed in the same manner as gunpowder: a piece of it is rammed down the barrel, then a bit of wadding, and after that a ball; a copper cap ignites and explodes the cotton. ”

“ The French cover their bullets with German silver, a substance made of nickel, zinc and copper; and in order to put as little strain upon the rifling and projectile as possible, the rifling of the gun is made with an increasing twist, and has no sharp edges. The French rifle is made very strong at the breech and is of tempered steel throughout. In this way the French have made smokeless powder a success--a smokeless powder made substantially of a character such as I have herein described. ”

“ As you know, the outside of most kinds of grenade is a thick metal case serrated with deeply-cut lines that cross each other like those more shallow sunk lines on crocodile-leather, only at right angles. These lines of weakness, cut into the metal, mark out almost the whole of the case into little squares standing up in relief, sixteen or thirty-two or forty-eight or seventy-two according to type. The burst, if all goes well, attacks the lines of weakness, cuts them right through, and so disperses all the little squares of brass, cast-iron, or steel radially as flying bits of shrapnel. ”

“ It may be said, why not select the metal—cast iron, bronze, or steel—and having determined on the pressure to be resisted, and the factor of safety to be allowed, and knowing the resisting power of the metal you have selected, make the walls thick enough, and then all that is needed has been attended to. Happy would it be for the gun-maker, if a gun could be produced of reasonable strength, combined with manageable weight, by such simple means ”

“ To obviate the serious results that may arise from the wedging of the flanges of a cast-iron projectile in the grooves of a rifle-cannon, it is frequently covered with a coating of lead or other soft metal. Cast and wrought iron have also been combined with success, and also cast iron and soft metal in such a manner as to attain the strength of one metal and the softness and expansibility of the other. Other metals, such as brass, are also used in projectiles of special construction. ”

“ In the former, all the larger cannon belonging to the official system (both siege and sea-coast) are made of the cast metal, whereas the Parrott gun and the new rifled pieces are a combination of both. (See Ordnance, Construction of.) The metal chiefly employed in England is wrought iron, in combination with steel; the largest guns made at the Woolwich Arsenal are of this nature. Bronze, except as modified by the Austrians, has now nearly entirely gone out of use as a cannon metal. In France and the United States, field-pieces, mortars, and howitzers are still made of this material. ”

“ The ordinary service cartridge consists of a brass cartridge case, a primer, a propelling charge of smokeless powder, and a bullet made with a jacket or envelope of cupronickel inclosing a lead slug or core. Cupronickel is a hard alloy of copper and nickel. Steel would be the ideal covering for a bullet because of its cheapness and availability, but steel has not been used because it is liable to rust and to destroy the delicate rifling of the gun barrel. ”

“ There is a sound of fumbling at heavy cartridge-boxes, of tearing paper, the whee-ep of the rammers springing from the pipes, a phosphorescent gleam of steel as they whirl in air, a muttered malediction as some fellow's cap is knocked off by an awkward neighbor. There is a dull pounding, as the heavy bullets are driven home, a clicking of gun-locks, as the little copper caps are thrust upon the cones ”

“ The locks and the large and numerous mounts on the stock are elaborately chiseled steel in strong relief with designs of animals, monsters, and semi-human figures against a background of floral arabesques.
Not all flintlocks were on firearms. The same mechanism was used on tinder boxes, alarm clocks, and gunpowder testers. The powder tester (Fig. 49) was like a pistol with a friction cover closing the mouth of the barrel. It was loaded (of course without a bullet) and fired. The force of the explosion blew the cover away from the barrel against the friction of a heavy spring ”

“ Extent of range and accuracy of fire in gunnery will in future be of so much importance in war, that it is not extravagant to assert, that in contests between well-matched belligerents, the precious metals (if they gave any advantage to the user) would be unhesitatingly used in projectiles. But on the score of economy, science need not be impeded. Gun-metal projectiles and cast steel cannon would work as effectually together as lead and iron in small arms. ”

“ GUN-BORING MACHINE.
GUN-MOULD.
“Ordnance,” or great guns are made of cast-iron or of gun-metal (a mixture of copper and tin) , but experiments have lately been made with wrought-iron and cast-steel, with the view of obtaining a tougher and more durable material. They are cast solid, and afterwards bored with a machine. ”

“ I had at that time a decided objection to all steel, as the following quotation from “The Gun” will show:—
“We recommend hammer-hardening in all mixtures containing iron. If you throw the iron aside, and confine your manufacture wholly to steel, it would be an evil, from this simple cause:—steel is of itself close enough in the grain; hammering it, therefore, in a cold state, only tends to make it more brittle. But the reverse is the case with iron: the more it is beaten the greater becomes its tenacity ”

“ The improvement in the manufacture of gun-barrels depends on the quality of the iron entirely; for it would be a useless waste of time to endeavour to make a good barrel of inferior metal. Science and experience have worked a wonderful change in the mixture of the superior qualities of iron: we have had announcements of silver-steel barrels at ten guineas a pair in the rough, of Brescian steel barrels, carbonised iron, and I know not how many more descriptions or compounds of metals, to form the best material for high-priced barrels. ”

“ Figure A represents the explosive bullet. The perpendicular stem, with a piece of thin copper hollowed, and a head over it of bullet metal, fitted a cavity in the bullet proper below it, as seen in the engraving. In the bottom of the cavity was fulminating powder. When the bullet struck, the momentum would cause the copper in the outer disc to flatten, and allow the point of the stern to strike and explode the fulminating powder, when the bullet would be rent into fragments which would lacerate the victim. ”

“ This iron, or rather steel, is formed into various instruments by being repeatedly heated in a forge, the heat of which is urged by a pair of double bellows of a very simple construction, being made of two goats’ skins the tubes from which unite before they enter the forge, and supply a constant and very regular blast. The hammer, forceps, and anvil are all very simple, and the workmanship (particularly in the formation of knives and spears) is not destitute of merit. ”

“ Steel barrels are more plentiful: they care not so much for the price of the metal; it is the after repeated manipulations that are evaded: the labour and loss of material is too much, and is necessarily “shirked,” and argument is always met with the answer, “We see nothing in it.” Yet the words “laminated steel” are to be found engraved upon barrels of the lowest quality of iron of which double barrels are made. Iron twist is subjected to a similar process to that already described as employed in producing Damascus iron, and which may be termed common iron Damascus. ”

“ The explosive bullet contains at its nose a small percussion cap, which, upon striking, explodes a charge within and scatters the bullet in tiny fragments, thus tearing a large and ghastly hole in anything in which it is embedded. Some of the poisoned bullets contain no poison, being a composition of lead and copper instead of steel and nickel, as our bullets are now made. ”