doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com examining damascus barrels

For your interest Bro. Bonny

"The Irish Industrial Exhibition of 1853: A Detailed Catalogue of Its Contents"
John Sproule, 1854
http://books.google.com/books?id=cNKl8YYZejsC
There are two processes by which a bar of iron is converted into a tube for the purposes of the gunsmith. First the simple though imperfect method of employing a flat bar, equal in length to the required barrel, and in width somewhat exceeding its circumference, and rolling it up until the edges overlap, to be finally welded along its entire length. Of late years an improvement has been effected in this method by the introduction of steam-power. A short bar is turned up and welded at one heat, and is then drawn out to the required length bv passing it through successive rollers. Such barrels are only used for the plainest work, and an much inferior to those produced by the second method. In this more perfect process the bar of iron, now called a strand, is coiled round an iron rod or mandril of the same size as the required bore; and the spiral so formed having been brought to a welding heat, and struck on the end to join the edges, becomes a continuous tube in which the grain of the material runs round the barrel, thereby insuring the greatest amount of resistance to the expansive force of the charge. The advantages of the latter method are numerous. The fibres of the iron, instead of being torn asunder by bending the bar parallel to its length, are rather condensed and closed together; and, accordingly, the better description of barrels have been manufactured in this manner for a long period. Among these are included the varieties called stub-twist, plaited-twist. laminated steel, Damascus, &c., which all partake so far of the common character that they are forged according to this process, but differ in the preparation of the strand. Thus, in stub-twist, a bar of iron is made as follows: � A quantity of stubs, i. e., small pieces of iron or steel, are raised to a welding heat, and consolidated by a few blows, and then drawn down between rollers to the required size. The excellence of the material depends on the quality of the stubs employed; that being in most repute formerly which was manufacture I from horse-nail stubs, or old horse-shoe nails collected by the farriers. Of late years these have deteriorated in quality, and it became necessary to apply, in the preparation of the strands, other processes which have for their object the purification of the iron, by twisting and hammering, and the introduction of carbon by a partial admixture of steel. The first of these � that of making plaited twist � is conducted as follows: � Two square bars of stub iron are separately twisted at a red heat until the whole rod has the appearance of a four-threaded screw, the threads being formed by what were the angles of the bar in its untwisted state, the one having a right-hand turn, the other a left. These rods, so prepared, are welded side by side to form the strand, and the grain of the iron presents, when finished, that feathered or plaited appearance whence it derives it�s name.
Steel barrels are made in a somewhat similar manner as just described, the material instead of stub iron, being prepared from soft steel, which is decarbonized in the course of manufacture.
The process of making Damascus barrels is more complicated, as involving a greater number of stages. The strand in this case is composed of three or four twisted rods instead of two, and they are all generally twisted in one direction; but it is in the manufacture of the rods themselves that the essential difference consists. These are no longer stub iron or decarbonized steel, but are formed of from twenty to four-and-twenty alternate layers of iron and steel welded together. The effect of this arrangement is, that when the barrel is finished, and an acid applied to the surface, the iron layers are rapidly eaten away, while the steel remains comparatively intact; and the whole presents that beautiful pattern, celebrated (long before the method of production was understood) as some secret prowess known only to Eastern armourers, and supposed to have originated in Damascus. The credit of rediscovering it in these countries a due to a Dublin house, a Messrs. Rigby, of Suffolk- street, whose experiments were brought to a successful result in the year 1817.

There was I believe well documented cases of Damascus barreled guns bursting at a point several inches down the barrel in the early days of Smokeless powder. Two wrong conclusions were drawn from thee bursts.

1st was that smokeless burned slower than black & thus stressed the barrel more at a distance from the chamber. Prior to the 1920's with the advent of progressive burning shotshell propellants all smokeless shotshell powders were faster burning than black.

2nd was the fact the Damascus was the cause. At that point the vast majority of guns in use were damascus so if a barrel burst it stood a very high likelihood it would be Damascus.

Another member here several years back posted a most plausible cause of these bursts. At that point shells, even factory ones, were being loaded with primers which had been developed using Black Powder. Smokeless is harder to ignite. I once read of a "Test" performed on a modern made .50 Cal Muzzle Loading rifle barrel. The barrel was filled half way with powder & the other half with balls & fired. It withstood this load with flying colors. A normal charge of powder was then dropped own the bore & a single ball pushed "Part Way" down the bore. Upon firing the barrel was blown apart at the obstruction.
It is highly likely something similar was occurring in these early "Damascus" bursts. Upon firing just enough ignition was occurring to drithe shot down he bore a bit & then complete combustion took place. This actually resulted in an Obstructional burst, but the barrel was known to be clear prior to firing the load. It was actually becoming its own obstruction.
Similar occurrences have taken place in high capacity magnum rifles which wold handle a full compressed load of a slow burning powder without a hitch. Some shooter then desiring a softer recoiling practise load would load a half charge of the same powder & Blow the gun to bits.
The possibility of this occurring with shotshells loaded to a very low pressure with slow powders along with the likelihood of squibbs as the temps fall is Why I "Quit" the practise.

To me this is the first commandment when dealing with and shooting vintage guns...

Thanks all. The gun is high quality, i wouldn't really bother with it otherwise and is in very good condition. The only issue is it is a little tarnished from sitting in a gun case or gun rack. Nothing that a good polish wouldn't sort out. Mechanically the gun is good too, no butchered screw slots or signs of the usual kitchen table stupidity.

Thank you for restating that explanation, Miller. I agree that this detonation could very well have been the cause of those barrel destructions.

One thing I do not quite understand, tho', is your comparison between the burning rates of smokeless powders and black powder. If what you stated is true, it must have something to do with being confined, because smokeless powders of today, when burned in an unconfined condition, burns MUCH slower than black powder.

When I was actively competing in BP rifle and shotgun matches I would occasionally participate in a "mini-seminar" for civic organizations, SCV chapters, shooting ranges, etc. We would basically just give a brief explanation of black powder and how it should be used, stored and handled in regard to firearms. One part of our demonstration was a burning rate demonstration, in which we poured a small "stream" of each in a little trough that had been routed into a 1" x 6" x 10' board. The end of the line of each was lit, and you watched as it burned the length of the 10' board. In a nutshell, the smokeless burned, at a constant but fairly slow rate. When the black was lit, in a flash it was all burnt and gone, instantaneously. For visual understanding of what we did, watch this:

https://www.youtube.com/watch?v=DXGkJkdvoIc

SRH

As Miller said, Progressive Smokeless (DuPont Oval) burns slightly slower than BP. Progressive Burning DuPont Improved Military Rifle (I.M.R.) Powders were introduced in 1914. DuPont Oval was developed for the 1922 introduction of Western Cartridge Company�s 12g �Super-X Field� 2 3/4� 1 1/4 oz. 3 3/4 Dram Equiv. shell.



The early Bulk and certainly Dense Smokeless did not



Modern dense; possibly Hodgdon Clays. Courtesy of http://www.arizonaammunition.net/



Shotgun Smokeless Powder DDT HAS been documented experimentally
http://www.trapshooters.com/threads/smokeless-powder-ddt.245629/

Stan;
Yes the Slower & faster in my statement is as appl;ied in the shotshell. As can be seen in the charts Drew posted DuPont Oval was the only one which had a slower pressure rise than black. The rest were all faster reached a higher peak & then fell off quicker. As DuPont Oval, or other progressive shotshell powders were not available for about the first 2� decades of smokeless powder use it becomes obvious those early bursts were not brought on by the cause to which they were attributed at the time.
Black Powder has the unique attribute of burning at essentially the same rate regardless of other factors,so yes it will burn unconfined while smokeless can be hard to ignite that way. The more heat & pressure is applied to smokeless the faster it burns.This is actually the attribute which allowed it to act in such a manner as to cause those bursts through delayed burning, a type of a "Semi-Hangfire" if you will.

Thanks, Miller, I felt it had to be in a confined space. But, it's more than being hard to ignite, evidently. Interesting that it performs so much differently when unconfined.

SRH

I think I remember seeing a written statement published by Ithaca, saying Damascus barrels are dangerous and should not be used. Of course I assume this was to boost new gun sales. Has anyone seen this, or am I more confused than my lovely wife contends?

Deflagration ?