doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Blow Up EUREKA

Will be dropping off the above barrel with TEAM Monday am, and hope to have more images to post. Still no word from METL

And mailed this request today. I've not found any documentation as to who/why the shell makers decided to place the warning. There was a reference to SAAMI here

August 24, 1948
Remington Arms Company Inc., Service Division
Subject: Heavy Loads in Damascus Steel Barrels
A number of accidents have happened in which Damascus barrels have been blown up with progressive smokeless powder. It has been felt that the reason for this was not only that the loads were heavy and that the guns were not designed for such loads, but also that there is a possibility that such barrels have become weakened with the passage of time due to unsuspected corrosion to which they are susceptible to a much greater degree than modern types of barrels.
It is a great many years since Damascus barrels have been made and sold by American gunmakers. It is felt that unsuspected corrosion of this type of barrel is making the continued use of these guns a hazard.
The conclusion was reached some time ago by the Technical Committee of the Sporting Arms & Ammunition Manufacturers� Institute that sportsman should be warned against the use of present day smokeless powder loads in such guns regardless of whether they are heavy loads or so-called light loads.
H.L. Hendrix


Rick Patterson
Managing Director
Sporting Arms & Ammunition Manufacturers Institute
11 Mile Hill Rd
Newtown, CT 06470-2359

Sir: I am researching an article on Damascus shotgun barrel safety. Could you please confirm that the "These shells must not be used in guns with Damascus or Twist Steel barrels" warning on shell boxes appeared in the late 1930s as a result of a recommendation by the Technical Committee of SAAMI? Would you have a copy of that recommendation? Does SAAMI now have a position on the use of Damascus barrel shotguns with smokeless powder loads?

Gee... wonder what they might say....

Hoping not to waste Mr Patterson's time, I did check the site
http://www.saami.org/
The shell box warning does not appear, nor could I find any mention of Damascus outside the glossary.

I doubt if there will be a response, to a non-member, but if forthcoming will let the curious know. If someone here has a connection with the Technical Committee, I would most appreciate you making inquiries.

+2

Interesting to note that when a steel barreled gun blows up, which happens about as often as damascus guns, ammo is usually the first suspected culprit.

There have been a number of guns "Blown Up" having steel barrels & firing factory shells. They just don't attain the Notoriety of those having Damascus barrels or using reloaded shells, or Both.

Yep. I know of such a case and his settlement with whomever prevents his discussing the incident.

Exactly - well put.

It may not be all bad to note that the reloads in this case were looked at a bunch more carefully than we normally get here about. Still, there might have been loads available that weren't so high a pressure under ideal conditions for typical clays shooting.

Almost any time something looks like a bulge in a barrel, there seems to be a lot of feeling that an obstruction was present. There's probably different situations. I think we're lucky to get a little different look at the barrels through the efforts here.

I wonder if this is like saying, "Most tire blow-outs on Trans-Ams involve mag rims, so mag rims must be the culprit."?
Never mind the fact that most Trans-Ams wear mag rims.

Similarly, because of the special dietary needs of vintage guns, I'd guess that a high percentage of such guns are fed reloads. So yes, when a vintage gun blows there is a good chance the shell in it was a reload. But is there a relationship?

UPDATE:

1. No word from SAAMI

2. TEAM has finished radiography on 3 barrels but final analysis awaits the return of the senior tech from Hawaii. I hope to find a crack on the Syracuse Arms twist barrels, which can then be sectioned and examined by METL

3. Fascinating meeting this am with Adam at METL. We reviewed most of the images, both SEM and photomicrographs 20X to 100X. He's going to send a very interesting image which I'll post soon, and the other metallurgists in the office are having a grand time looking at something never before recorded (the exciting life of engineers! )
Very short version
a. There was no evidence of low cycle fatigue
b. The blow out was from an over-pressure event with ductile (stretching and sheer) fracture, with nothing to suggest an intrinsic wall defect. Photomicrographs can not prove obstruction vs. shell overload, but certainly the bulge suggests obstruction.
c. The failure did not occur at a ribband weld line
d. One crack in the piece that was retrieved was just that; a fracture through a cast iron section. Another crack did follow the low carbon/'mild' steel - cast iron juncture in one of the rods ie. within the scroll.
e. As above, the images show mild steel - cast iron - and interfaces with some blending of the metals.
f. Adam showed me a freshly cut piece of the barrel fragment, and it looks like any other cut of metal ie no 'orange lace'.
Monty sent me a pitiful Smith Twist barrel with marked rusting in the bore. I'm going to use it for tensile strength testing, but first will have Adam examine the cut edge for evidence of the mythologic interlaminar rust.

Tensile strength testing update:
I've received contributions of 3 Twist, a Damascus-Twist, and a Crescent Armory steel barrel to section and destroy. A Parker Vulcan steel is on the way. I'd very much like to have 2-3 higher grade Crolle barrels and more fluid steel pieces.


For comparison, I thought I'd include Zircon's examination of 2 Sherman Bell blow-up barrels. Remember the barrels were subjected to sequentially higher and higher pressures.

http://www.familyfriendsfirearms.com/forum/archive/index.php/t-55364.html
The damascus barrel let go by a mechanism known as low cycle fatigue. Each succeeding round had higher and higher pressure. After several rounds, a crack started to emanate from the extractor screw hole. Each successive round caused the crack to open up just a bit further, until finally the overpressure could not be contained and the remaining ligaments failed in a ductile fashion. Ductile failures in steel look like a taffy pull at about 1500 to 3000X magnification using scanning electron microscopy. There is a cup and cone appearance with a lot of microvoids present. This appearance is a dead-set giveaway to a ductile fracture.

The homogeneous, "fluid steel" barrel failed by brittle rupture. The fracture surface is more or less smooth, but has some "rivulets" in it that point back towards the initiation point, which was the screw hole, again. The fracture surface was about 3X as long as for the damascus barrels. In other words, the same 30,000 psi final internal load created a lot more fracture surface in the homogenous barrel than in the damascus barrel. This indicates that, for an equivalent-length fracture, it took less energy to open up the homogeneous barrel than for the damascus barrel.

In the case of the damascus barrels the crack spiraled around with the weld pattern, but it was not on a weld, rather it was on one of the in-between areas. The spiral welds remained tight and the parent metal is what failed. This may seem pretty amazing, but in many, many instances the actual steel welded structure is stronger than parent metal.