To elaborate on Pete's accurate observation. We only have TWO crolle Damascus composition analysis, both specimens c. late 1890s, and both have very low carbon so it appears the Damascus makers stuck with something like "Low carbon, Low alloy AISI 1002-1005" for pattern welded barrels. I have one more crolle sample and one twist sample to analyze also.
“Manufacture of Damascus Gun-Barrels”, E. Heuse-Lemoine, 1884
From the remotest times, this industry of gun-barrel manufacturing has been practised in the Valley of the Vesdre from Nessonvaux to Chaudfontaine. Under the first French empire, our renowned barrel-smiths furnished the contingent of work people for the Imperial manufactories. At that time all the barrels for military guns were forged by hand; the preparing of the iron for these barrels was exclusively performed with charcoal and the superiority of this iron to that preparation with coaks is well known, in our day of the specialty of fire-arms as we shall show a little for further.
The barrels thus manufactured with good charcoal iron proved to be already a great progress with respect to solidity, but offered of the Damascus appearance which was visible by certain traces of the spiral produced by the appearance of the fibres or the varnish of the metal.
The steel as well as the iron for these fine Damascus barrels must be of a special quality, which is to be got in Wesphalia in Germany from the manufacturers of this metal, especially from the firm Koite of Luttringhausen which supplies as with all we want in this article in which enjoys all the great reputation for this type of article.
In this kind of curled or other fine Damascus, we may not use any other but we refined charcoal iron, because it has, contrary to the Swedish iron, the propriety of being very light colored and consequently of a contrasting hue with the steel and moreover by its natural purity contrary to the coak iron it does not require nor want to be welded at a high temperature for being purified; as we just observed it would be in discord with the steel, its alloy, which cannot and must not be exposed to excessive heat when welding. (It is the [unreadable] Stok Company at Grivegnee [Liege] which enjoys the highest reputation for the preparing these packets of lumps for welding and reducing them into stripes.)
Unfortunately the manufacturing iron by means of coaks is almost everywhere prevailed over its manufacturing with charcoal on account of the extensive use of coaks in all kinds of metallic construction and especially because it is a great deal cheaper, so that charcoal iron becomes more and more scarce.
In Belgium there are only Mess. Mineur et Son a Couvin who manufacture and furnish us this speciality of iron, which we must declare give us the greatest satisfaction by its undeniable superiority and which it is really indispensable for manufacturing fine Damascus barrels.
A great number of fruitless trials have been made with all their similar metals, among others Swedish iron which has the advantage of being fibrous but it also has a defect of being a steely nature, so that it is not produce a beautiful Damascus; it's hue is blending and confounding with that of steel, so that only an imperfect Damascus is resulting from it.
The coak-iron however is also much used in manufacturing barrels on account of its being very cheap, but it cannot be employed in manufacturing the superior kind of Damascus barrels on account of its impurities and of some other defects unseparable from its nature. Therefore it is only made use of in making common and cheap barrels.
Here is yet something to be noticed in favor of the charcoal-iron, for the stripes composed with this kind of iron may be wrung and twisted, and furnish a very fine Damascus, where the coak-iron can only imperfectly be twisted and gives a coarser Damascus.
The same observation may be made respecting the smithwork, more the man is hammering the Damas composition made with charcoal-iron, more it gains hardness and metallic elasticity, were as the contrary takes place in the same composition made up with coak-iron.
The New York Times, May 3, 1896 “Costly Belgian Gun Barrels”
The United States Consul in Liege describes, in a recent report, the manufacture of and trade in damascus gun barrels, wholly hand made, in the valley of the Vesdre in Liege Province. These barrels are for sporting guns, and the industry is many years old, the workmen in the villages in the valley being almost all gun barrel makers, and the trade descending from father to son. The best barrels are a combination of the best primary substances, welded and forged by the martelage ‘a froid (“cold hammering”) process; the steel comes from Westphalia, the iron is manufactured at Couvin, in Belgium; the coal, which is specially suited for the work, from the Herve’ Highlands, in Belgium, while the motive power of the factories is obtained from the River Vesdre.
Medium quality barrels are made of coke iron and steel, while the superior quality, which are produced in the Vesdre Valley, are made of charcoal iron and steel. An ingenious “marriage” of these metals gives a composition which, when manufactured, guarantees the required solidity and resistance.
