This may be of interest to you.
from the book "The Gunsmith's Manual" 1883
"Gun-Barrels -Best Materials for.- The barrels of the finest and best guns, either Damascus, or other steel, or iron, are formed as made in Europe and England, of scraps of iron suited to the purpose, and selected with great skill and the greatest possible care. These scraps, which are usually bought up about the country, are placed in what is called a "shaking tub"-a vessel which is violently shaken and rocked about by machinery or otherwise(depending on the particular locality)for the purpose of scouring and brightening the scraps. This done, they are carefully picked over by adepts, who cull out the unsuitable pieces. So rigid is the culling that it often happens that out of a ton of scoured scraps not more than one hundred pounds weight of them are chosen as suitable for going into the best barrels.
Among the scraps usually thought to be best are old chains that have been used for many years, the wear and rust of time having left only the best elements of the iron. The Damascus steel, which has attained to so high a reputation, got it by being manufactured out of old coach springs. Of course it is not all made of coach springs now, but it was in years ago; agents then travelled all over the country hunting and buying them up, paying a much higher price for an old broken spring than a new one would cost it's owner.
On Making Gun-Barrels.-The selected scraps to be worked into gun-barrel material are cut into small pieces and thrown into a furnace, where they are exposed to intense heat until fused,after which they are brought forth an adhering mass and placed under a hammer, which drives them together and forges them into bars. The bars are next rolled into thin plates, and then cut into strips twelve inches long and six inches wide. The very best guns are made of a combination of iron and steel. Both materials having been rolled and cut into sheets of exactly the same size, these sheets (one-fourth of an inch thick) are piled upon each other alternately to the number of thirty, and subjected to a welding heat; they are than driven together under a five-ton hammer into a consolidated slab. The slabs so formed are next worked down into one-fouth inch square rods. the more the material is hammered and worked the better it is. The rods are next twisted until they present the appearance of a strand of rope, some rods being twisted to the right and others to the left. Two rods with opposite twist, are heated to the welding degree, placed upon each other, and rolled together; they are now in a narrow slab, presenting that fine curl of "grain" peculiar to the damascus, or that beautiful wavy figure peculiar to the laminated steel,as the case may be. The next operation is to coil one of these slabs around a mandrel in a spiral form, and weld it securely under the blows of hand-hammers. It is now a gun-barrel in the rough.
Finishing and Proving.- The rough barrel goes from the welder to the borer,where it is put through the process of "rough boring." From the "rough borer" it goes into the hands of the "fine borer"
who bores it out smoothly and to near the size it is to be when finished. Another operator then takes it in charge and dresses it to smoothness externally, then the "tester" takes it and dips it into strong acid, which soon shows any imperfection in either twist or welding that might exist. If not perfect, it is sent back to be worked over; if all right, it passes to the next department, where it is straightened inside. This part of the work is governed entirely by the eye, and hence demands the services of a workman of great skill, and experience.
Having been "passed on" by the "staightener", the barrel goes to the "turner", who turns it in a lathe until the outside is true and correspondingly straight with the interior, and is exactly of the required weight. If the arm is to be a double-barrel shotgun, the barrel next goes into the hands of a workman who joins it to another barrel with the utmost nicety; to attain which, levels and other suitable instruments are brought into requisition, Like the man who staightens the bore , the man who joins the barrels must be a workman of great skill.
The next operation is to braze on the "lumps;" then next in order , the ribs are put on. Now comes the "proving." The rear ends haveing been securely plugged, they go to the proof department, where is placed into each barrel fully four ordinary charges of gunpowder; then, atop of this, a wad of strong brown paper, rammed securely down, then a leaden bullet large enough to exactly fit the bore, and then another wad of brown paper. The charge is fired, and if the barrels stand the ordeal unfazed, they are ready to be fitted to the action; otherwise, they go back to be worked over. In some houses the "proving" is done before the barrels are joined together."
Pete
