At a shoot today and this happened. Important thing is shooter was unscathed. What do our experts have to say?

. Here are some details. LC Smith Feather weight. Factory trap load.

Without doing a full metallurgic testing of the steel the obvious thought was a blockage . Questions to asked what cartridge was used and if it was a factory or home load .
I have seen many burst barrels and some you can never say the exact cause ,its very fortunate no one was injured .

Just old tired steel...

Obstruction + SAAMI pressure = burst barrel, whether old or new.

SRH

Did this happen on the first shot of the day?
Was the fired hull retained?
Is there a dent on the left barrel or is that just a shadow?
I’m guessing an obstruction or restriction. Without a full examination we are all guessing which is what was asked for.

Reminds me of the burst I saw when a confused trapshooter loaded pistol powder in his reloads. Same longitudinal ripping. About the same distance down stream too.

Is it a later Field with a Single Sighting Plane rib?
May we assume you have already measured the wall thickness around the edges of the burst?

It does not look like an obstructional burst with a ring bulge, and if the top rib is not lifted likely was not; the bottom rib obviously separated





nor does it look like the usual thin wall split



Circumferential burst at mid-barrel with jagged edges (abrupt cleavage with little plastic deformation) suggests a barrel defect.

At the breech, very high pressure.



Could there have been a previous dent or bulge that was inexpertly repaired?

This would seems to be a good opportunity for Frank to cut and paste from a textbook of metallurgy and help us understand how barrel steel gets "old and tired"

Let's just say for now, that I know a lot more than I'm letting on. Nothing to lose here, look at the pics make your best guess and if you can explain why.

It is, of course, always harder to make a diagnosis from pictures than hands-on. There does appear to be funneling at each end of the burst & a bulging of the bottom rib, though doesn't appear to be in the top rib.
As to "Pistol" powders, shotgun powders & pistol powder have a lot of overlap. There are shotshell loads using Bullseye & pistol loads using Blue Dot & virtually all powders with burning rates in between.

I assume the mentioned substitution of pistol powder was meant as an overload of fast pistol powder in place of a heavier load of slower burn powder. An overload of fast powder should result in a chamber burst, not down ahead of the forend. Some other factor may well have been involved in that case which was overlooked once the powder mistake was discovered, hard to say without more info.

This barrel in the pictures does not look to be overly thin. It may well, however, have been struck thinner on the outer portion that the inner, which could account for the top rib not being bulged. I do not see it as being the result of "Tired Steel".

I will vote for an obstruction. Even I can be an expert on the internet.

I'd say there was a blooper and the wad didn't exit. Next shoot boom. I'd guess in a fast shoot (like a flurry) the shooter might not have noticed the blooper.

There is some suggestion of a "banana peel" burst

Chamber burst = too much pressure. Barrel burst = obstruction. The pressure could have been very high and the barrel could have been thin in that area also contributing to the burst, but I still go mainly with an obstruction.

I can agree with tut on this one. Only other possibility is a base wad but less likely that far up barrel.

The long-shot answer is a live round that made it that far up barrel and discharged when struck by the next fired round. The ragged break lines fore and aft of the rupture seem to indcate possibility of a very high pressure at this point. More so than an obstruction might cause. ???

John

I remember reading about a reload with wrong/damp powder where the ignition was delayed, and the primer pushed everything down the barrel just a bit, wherein ignition occurred a fraction of a second later, and split the essentially plugged barrel.

Just a guess but by the looks of the rip it looks like there was a smaller shell in the chamber and then a loaded 12 ga. hull or a stuck wad from the previous shot.
Where that rupture occurred pressure should have been down past half of chamber pressure if not more.

David,

I think you are right about the smaller shell in the barrel. The ripping of the forward part of the rupture suggests more than just a blockage. I can imagine that the smaller shell detonated and caused additional damage.

It is great fun trying to over interpret visual data.

When do we get to find out what the real answer is?

This evening, so get your answers in.

Obviously, this was caused by the barrel wall failing.

If only we could recover the missing segment of barrel, we could send it to METL for expert metallurgical analysis.

If the initial report found ferrous contamination in the braze joint, we could show an EDX spectrograph the next day to then say that the contamination was manganese sulfide.

Perhaps the steel in the missing segment was burned. But NOT burned in the normal sense where severe overheating actually burned carbon out of the steel, rather burned like a dirty scorched cooking pot.

Then, a totally erroneous statement such as this always makes a lasting impression upon the impressionable:

[quote=Drew Hause] Oxidized debris = burned steel [quote]

In addition, it would be most helpful and informative to post a bunch of photos of totally unrelated barrel bursts to cover the fact that you don't have a clue.

This is the Doublegunshop equivalent of attempting to portray yourself as an Award Winning Winemaker, when nothing could be further from the truth.

Unfortunate that cowardly bullies like William and Frank lurk in threads, waiting for others with the willingness to provide opinions (which may be proved wrong) or factual data, but lack the cojones themselves to offer anything but BS and criticism of those opinions, and can't help but show their obsession and hatred by reviving past feuds.

Sorry gentlemen, then I'll give it a rest

A. Pagliuca, Metallurgist
Metals Engineering & Testing Laboratories
"The braze contamination descriptions are kept vague because that's about as conclusive a statement we can make based on the data. The concentrations of iron and oxygen detected could technically be consistent with corrosion (rust) or overheated steel. Based on where it was observed in the braze, we need to refer to it as ferrous braze contamination. We don't know exactly what it is. This could have occurred during the brazing process (likely) and been exaggerated over time by successive heating cycles, moisture, etc via possible alloy segregation effects, electromigration and such phenomena."

This is the braze joint with manganese sulfide inclusions and ferrous debris



Keith - how about you start another thread instead of dumping equine fecal matter all over this one? Maybe let us know what your safe wall thickness criteria are?

And back to the topic - what is your opinion as to the cause of the "barrel wall failing"?

Drew, never apologize for not being in the wrong.

The cretins will as the cretins do. Just keep doing what you do and we will all benefit and enjoy it.

One of the pictures that I thought was interesting on the other thread showed the 'ferrous braze contamination' appearing to be completely encircled by braze. It had the look to me of what flux can do, clean oxides off the steel and allow the braze to flow. In other words, it still could be a successful and adequate braze if(?) the braze still flowed and bonded to the rib and barrel.

Some of the past pictures seemed to show braze that was still bonded to the rib, but very little to none on the barrel. I think the worrisome oxides are not the small islands that're completely encircled by braze, but the seeming unbroken sheet of oxide, possibly rust, that that looked to run along the barrel and may have penetrated the barrel in the form of pitting at what I think was referred to as the intiation point.

Back to this gun, since there's an answer to come, I'm going to guess there's another picture coming of something in the barrel. Maybe, a wad or part of a separated hull based on how far downstream the burst seems to be.

I do not believe this to be a typical 12/20 burst as the 20 will lodge in the forcing cone. This burst was out beyond the forend, too far for that.

Once the Ultimate Tensile strength of the steel is reached a burst occurs. I truly wonder how one tells how much more pressure was involved than that. As soon as that burst occurs the remaining pressure Runs Out the Hole in the Wall. There is ample & Conclusive evidence which has been collected for a century or two that an obstruction can build enough "Localized" pressure to burst the Finest & Strongest barrel.

I Eagerly await the verdict.

I hope its been a little entertaining and you have waited patiently, so here it is. But first a some info on the shooter. Master class in sporting clays as is his son who was present. Approx 60 years old. But the most important thing is I know and shoot with them and because he owned up to this whole situation, we get to armchair analyze it by letting me take pictures. No disparaging remarks about him are needed.

Shooter wanted to see if the LC Smith would function and fire before the sxs event started. He drained the shot only out of a pair of shells. Went to the practice field and fired both. Momentary lapse of reason on his part then occurred when he immediately placed a fully loaded round in the rh hand barrel and touched it off without checking the bore for the stuck wad. The stuck wad in the LH barrel was also still there at about exactly the same spot as the blowout. There ya have it. Watch out for yourself and keep an eye out for everyone else. Stay safe.

Yep; Obstruction burst, fit all the signs including location. Remember that no two bursts are identical. One looks at the signs, but do not expect to find an exact Twin which looks just like the burst in question.

As I mentioned in an earlier post the barrel may well have been struck a bit thinner on the outside than between the barrels, obvious if more was done after assembly. The pressure may have peaked Just high enough to stress this thinner area & the stiffening of the top rib would well explain it not being bent. Had the obstruction been heavier the pressure may have risen a bit faster & bent the rib. Remember also when the load hits a "Movable" obstruction the burst will normally be a bit forward of where the actual obstruction was located.

I am sure the Gentleman who did this learned his lesson well. No Criticism from me. Do thank him for sharing with us as to what actually occurred & allowing the pictures to be posted. We all should have learned a lot from this thread.

Caused by a brain fart...it could happen to anyone.

Glad you're buddy wasn't hurt.




No whiney X'spurt needed.

Thanks for the opportunity to see another barrel burst example, replete with the known cause. Excellent.

Bet he never does that again ..............

SRH

I think one possible take away from the scenario is that the pressure that caused this blow up might be symmetrical. Maybe as Miller pointed out, asymmetrical external appearances might have something to do with asymmetry of the hoop in the area. It could be that many blow ups would be ring bulges, but are altered by variables.

12brd - nice to have a definitive answer, and thanks for sharing.
It would be informative to know the wall thicknesses at the burst, and which trap load, if you could please ask the owner. Pressures at that point are probably < 1000 psi

1 1/8 oz at 1200 fps



That is called "brittle cleavage" (which does NOT mean the metal is brittle) in that there is little plastic deformation. A damascus barrel with a much lower yield strength will "stretch" before bursting, if the wall does not fracture along a weld.

Part of this burst appears to be along the ribband edge weld

In this case though, would the pressure in the area have exceeded what was expected to be normal when the second shell was fired into the obstruction? I’d also guess that if the wad only made it to the end of the forearm, it was probably just being pushed by the primer and there may have been a full charge of unburned powder between the wad and the following shell that was fired, if only the shot was emptied from the test hulls. Maybe.

Visual analysis is quite interesting to me and there are usually more clues than first observed. Some mentioned lack of a bulge ring to indicate an obstruction. Yet there is a large section missing between the fore and aft ends of the rupture point. If you look again at the second picture from the OP, the top rib has tracks left from the exiting metal. The exact rumpture point can be easily seen as well as the direction of the departing pieces.

John

I dated a girl once that had that...

Really Drew???... you want my opinion? When I provided my opinion in the original Southern Barrel Burst thread, you launched yet another of your virtuous personal attacks claiming that such an opinion without proper metallurgical analysis and barrel wall thickness measurement tools( in an area where such measurement is impossible without destroying the barrels) is irresponsible.

Shortly after that, you did your utmost to avoid admitting that my opinion closely mirrored the opinion of Dewey Vicknair, that you subsequently posted... save the part about "burned steel".

But that's OK because we should all know by now that when you attack me or jOe, it is good, and righteous, and virtuous, but if we respond to your personal attacks, it is cowardly, and indicates that we lack cajones.

I do note with some satisfaction that several of the guys who guessed the cause of this burst were pretty much correct, but our self-styled shotgun barrel guru was wrong again.

And where have we heard this before???



Why, we heard it from you Preacher... a number of times... before you returned with even more of your righteous and virtuous personal attacks. I guess there is no reason to trust or believe you now. In fact, didn't this fun little game begin when you started it all with your "Down One" thread where you personally attacked me, James M., and Dave K? I'm still confused why you found it so offensive that we used the term "LIBTARDS" to describe some of your pals who support anti-gun Democrats. You whined and cried that such a term is hurtful to parents of retarded children. Yet you never said a word when your pals such as Dr. Wanker or Last Dollar frequently used the actual word "RETARD" to describe Conservatives or Pro Gun Republicans. I've asked you to explain this hypocrisy several times now, but I guess you lack the "cajones" to give us an honest answer.

Dr Wanker using Re-Tard - post #500440


And remember when you used this as your tag line?

"Personal attacks only reflect the inadequacy of the argument, and the character of the attacker."

It was funny to see you change that tag-line after getting caught violating your own preaching.