All twist barrels undergo a similar round; the time and care bestowed upon them depending entirely on the price, which varies from one pound per pair down to eighteenpence, and in some instances lower.
In a former work I noticed the introduction of a villanous system of covering or plating barrels with fine iron over a body of very inferior iron. I here quote that description:--
The deceptions practised in this branch of manufacture are numerous, and injurious to the trade. For instance, if you wish to have a heavy single barrel made from Damascus, or any of the best irons, and you send to the manufacturer the weight of iron required, the probability is, that unless you superintend the manufacture yourself, iron of an inferior quality will be introduced into the inside of the spirals. By this fraud they obtain iron worth threepence a pound more than that which they knavishly insert into the barrel. I had been repeatedly told of this practice, but was incredulous. However, I gave an order for four very heavy rifle barrels to be made of Damascus iron. They were made; but on pickling these barrels for the purpose of showing the figure of the Damascus, I discovered that the iron seemed to be much more easily eaten away at the muzzle than on the surface. This led me to examine them, when I found that the inside was entirely composed of iron, over which the covering of Damascus had been twisted. But for the pickling, this fraud never would have been detected; yet for these barrels I was charged at the rate of two barrels for each. Since this occurred, I have subjected many heavy barrels to examination, and have found the fraud to be very common. The practice is not only dishonest, but spoils the gun, by destroying the shooting power, in consequence of the metals, being of different temperatures, not acting together at the moment of expansion.
Veneering or plating barrels is more extensively practised in Belgium than in any other nation we are acquainted with; they do not conceal it, but they use equally good iron, though not ornamented iron: of this there is much doubt. The method of accomplishing this is by having the iron required rolled down into ribbons of a thin description; these are twisted spirally round a tube of common iron having the fibres running length-ways, or parallel with the bore. The accompanying cut will convey an idea of this method.