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Sidelock
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Sounds like the forum's analysis was about right.


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BrentD, (Professor - just for Stan)

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I have a hard time saying that a gun that operated properly for 100 years before failing had a design defect. I think at that point you are passed the anticipated life expectancy for the design. That doesn't mean the failure wasn't due to the design I just can't use the word defect.

We all need to realize that when shooting guns this old--and I do it, my oldest is 1884--we are taking more risk than with a new gun.

So to me the question is finding indicators of potential impending failure.

Unfortunately, from the pictures of the destroyed barrels it looks like there is no way to tell if there was any visible sign on the exterior or interior that could have been a clue, however minor.

Anyone else have ideas on what to look for?

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L.C. Smith Maker, Syracuse manufactured about 1,600 hammerless guns. Hunter Arms produced about 530,000 Smith hammer and hammerless sidelocks, and another about 80,000 Fulton boxlocks. If they made time-bombs with an intrinsic design flaw, one would think a plague of blown barrels would be apparent by now. Clearly THIS 110 year old gun had a manufacturing defect, but would it have failed without an over-pressure load in a short chamber?

A study complimentary to the Birmingham Proof House Trial was published in in The Field June 6, 1891 by Horatio F. Phillips, a “staff experimenter” comparing brazed and unbrazed Steel and Damascus barrels
http://books.google.com/books?id=inQCAAAAYAAJ&pg=PA14&lpg
"These experiments serve to show what a very large margin of strength there is in a good gun barrel, when ordinary charges are used. The (Damascus) barrels which gave way earliest...had withstood the strains of…about four times as great as the regulation proof; while the steel barrels (Siemens-Martin and English “Superior Barrel Steel”) were tested…with charges averaging nearly five times as much as the ordinary proof-charge."

It would seem that this large margin of safety was what saved this gun until 2019. It is significant that there was no microscopic evidence of low cycle fatigue - the pressures to which the breech braze and barrel was subjected was below the yield strength of the steel. The failure was initiated at an area with inclusions and a braze joint contaminated with "burned" steel.

It would be quite interesting to evaluate the braze on the left, but this would require destroying the left tube, which still has some value, and more money wink

Other reasonable opinions are most welcome.

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Interesting. Since I reload that same hull--which I would shoot in short-chambered 16's if I currently had one--I'd be interested in knowing the formula used. I had mine tested by Tom Armbrust. Avg MV: 1182 fps. Avg pressure: 7420 psi. I've shot a whole bunch of reloaded 2 3/4" 12ga shells in Brit/Euro guns with 2 1/2" chambers. Pressure and MV very similar to my 16ga reload.

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re: how to evaluate vintage braze joints. Magnetic Particle Inspection (MPI) can't test what the stuff can't get to.

This is a negative image radiograph of a Smith barrel (you can see the bulge just forward of the chamber) which would be of no help in evaluating the integrity of the braze joint. There is porosity in the top rib and bottom rib solder, and pits in the barrel bore which can not really be differentiated from defects within the barrel wall.



The dark area just forward of the breech is silver solder joining the barrels

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re: the reload recipe. The shooter believed he was using factory loads, and has not responded to any of my emails since I received the barrels.

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Originally Posted By: Rigby
I have a hard time saying that a gun that operated properly for 100 years before failing had a design defect. I think at that point you are passed the anticipated life expectancy for the design. That doesn't mean the failure wasn't due to the design I just can't use the word defect.


Well Rigby, unfortunately, it is not considered acceptable here to use the brain God gave you. To question the conclusions reached here simply isn't welcome.

For example, I was roundly criticized in the first thread pertaining to this barrel burst for agreeing with another guys observation, and then elaborating upon that. The inclusion that is finally accepted as the point where the burst was initiated seemed apparent enough to the naked eye. And the corrosion within the braze joint was readily apparent as well.

The defect wasn't a "design" defect in all likelihood, because the vast majority of L.C. Smith guns with this construction have not failed... and most likely won't fail under similar circumstances.

The defect was there hidden within the steel before that steel was ever fabricated into a shotgun barrel. As I said in the earlier thread, steel is not necessarily homogeneous and free of internal flaws. Sometimes internal defects or inclusions are revealed during machining, and sometimes they remain hidden.

To say this steel was "burned" is silly. To burn solid steel without the addition of oxygen (as with a burning torch) usually requires a temperature above the melting point, i.e., roughly 2800 degrees F. At that ridiculously high temperature, all of the zinc would be vaporized out of copper-zinc brazing material. Here's what Prince & Izant, a manufacturer of brazing rod has to say:

Copper-Zinc Brazing Filler Metals

Copper-Zinc brazing alloys are used for their high strength and stress characteristics. These alloys are brazed using torch, furnace or induction heating but be mindful of overheating – doing so can vaporize the zinc and leave voids in the joint.


It is apparent that this braze joint was defective. We can never know if the corrosion got worse over time, or if it was this bad all along. Chances are that it got worse over time, or it might have failed decades ago. But we'll never know the chamber pressure when it blew up. The ferrous oxide contamination suggests that there was probably rust on the tube at the time of brazing, and that there was insufficient fluxing. As the cautionary note from Prince & Izant suggests, it seems very possible that there was overheating during the brazing process, leaving a void, but not nearly enough to burn steel. Burning steel is an EXTREME overheating that actually burns the carbon out of the steel.

Think about this... melting steel in an electric furnace doesn't "burn" the carbon out of it, so why would simple overheating during brazing burn the carbon out of the steel? And think about welding... where base metals and filler rod are fused by melting them together. How strong would those welds be if we "burned" the steel during that process?
Oh wait, scratch that thought... we're not supposed to think here, or question the Preacher.

Despite the thinness of the chamber wall at the point of the burst, this accident probably would never have happened with a good braze joint and barrel steel that did not contain a large inclusion (probably rolled-in scale)in the chamber area. Hundreds of thousands of L.C. Smith guns that didn't blow up are proof of that. The inclusion and its' location, combined with the defective braze joint created a perfect storm. There are still unanswered questions about the load or reload, and it seems strange that the guy who had this gun blow up while he was shooting it won't provide any more information. When I experienced temporary blindness after a complete head separation in a .22-250, I wanted to know why, and left no stone unturned.


A true sign of mental illness is any gun owner who would vote for an Anti-Gunner like Joe Biden.

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Well this explains a lot.

I experienced temporary blindness after a complete head separation.

Oops never mind my bad.
Misunderstood.

Last edited by Ghostrider; 06/05/19 09:54 PM.
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I've confirmed with the metallurgist at METL that the "contamination" between the barrel and top rib extension wedge is manganese sulfide and metal oxides ie. corrosion and "burned" (over-heated) surface steel and filler metal. "Burned" doesn't mean "melted" ie the surface of a cook pan left on the stove is "burned" and discolored.
Purposefully not understanding semantics in order to argue is of no help, but we are appropriately impressed.

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Originally Posted By: Drew Hause
re: the reload recipe. The shooter believed he was using factory loads, and has not responded to any of my emails since I received the barrels.


Per my previous statement, the load that blew the chamber certainly looks like a reload to me. It has the same Cheddite primer I use when reloading--which is different in appearance from the primer used in factory Herter's 16's.

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