Chasing The Blown Up Taurus Mystery. Here Is What I Have Found So Far

[mold maker]

Shuck's heck and darn, the attachment won't open.

[Omega]

Definately send these photos to Taurus, they may just surprise you.

[243winxb]

Post 40.
Cylinder timing problem. High pressure when the bullet made contact with the frame/barrel.

Unique does contain Nitroglycerin. This may cause detonation under some conditions.

Both ends of the cylinder were blocked just enough time to do the damage.

[35remington]

Ah, the “detonation”thing again. No accredited ballistician finds that credible with powders like Unique, and in my time, and with the Hornady plant so near, I have talked to more than a few.

The mysterious “d” word gets invoked when more prosaic causes for events get ignored.

A cartridge off center enough to be struck mostly centered on the primer will see the bullet mostly centered in the forcing cone. Since the forcing cone is in fact a cone, even such an slightly off center strike will see the bullet go down the barrel safely. The reduced diameter front of the bullet also provides alignment.

Off center does not seem plausible as a cause. Need to look elsewhere as that makes poor sense.

Jonp said the case was intact. Even if Unique or whatever powder was used could “detonate” it certainly did not here.

[35remington]

In addition, the only way the gun can fire is with the locking bolt in the cylinder notch. If anyone can make the hammer fall on any revolver they have when the locking bolt is not in the notch that is the first I have ever heard of.

I doubt this revolver is the exception. When the locking bolt is in the cylinder notch the cylinder really cannot be substantially misaligned with the forcing cone. The locking bolt stays in the notch throughout the firing event. Due to forces involved since it starts out with the bolt in the cylinder notch (or the gun won’t fire in the first place) the bolt stays in the notch throughout the firing event. Physics says so.

[Tackleberry41]

Im gonna toss out a theory that its just a marginal design. We have to remember Taurus makes these 45/410 chambers for the US market. In brazil, they sell them as 410 only. So a 410 will never see anything over that 12k pressure limit. So they design a gun for that use and no more. Now if Taurus was a better company, like Ruger lets say, they might overbuild the gun a bit. But I have not seen where guns in Brazil are made that well. If they can cut a corner...they will.

So maybe Taurus takes that same basic gun thats fine w 12k psi 410 shells. Then they ream them out to 45 colt, which reduces the cyl wall thickness. A company like Ruger would compensate, Im thinkin Taurus might not. 45 colt is already past that limit to begin with. Then you have that screwy chamber where yes a bullet can end up side ways, but still be forced thru the barrel. Lets imagine how that pressure wave would be, lets say its 14k, then bullet goes that inch or so of freebore, then wham is forced somewhat sideways into the barrel. One could imagine the pressure is gonna spike, and no where to go. Does Taurus even bother to proof test anything?

Proper metals = more money.
Better heat treatment = more money.

Not seen anything about the S&W governor blowing up with the same ammo in them. But S&W is a considerable jump in price and S&W will over build.

[jonp]

In addition, the only way the gun can fire is with the locking bolt in the cylinder notch. If anyone can make the hammer fall on any revolver they have when the locking bolt is not in the notch that is the first I have ever heard of.

I doubt this revolver is the exception. When the locking bolt is in the cylinder notch the cylinder really cannot be substantially misaligned with the forcing cone. The locking bolt stays in the notch throughout the firing event. Due to forces involved since it starts out with the bolt in the cylinder notch (or the gun won’t fire in the first place) the bolt stays in the notch throughout the firing event. Physics says so.

OK, I'll buy that. Let's move on to something different then.

[243winxb]

The explosive power of smokeless powder is extremely dangerous when confined to a small container. In addition, certain smokeless powders with a high-nitroglycerine concentration can be induced to detonate.

http://www.firearmsid.com/Feature Ar...ord_gunpowder/

[35remington]

That would be relevant if the conditions for “detonation” existed in the chamber of a firearm when a normal charge of powder was used. It does not.

The idea of “detonation” is that faster smokeless powder somehow explodes like dynamite every once in a while for utterly unexplainable reasons while somehow for the millions of other rounds that are fired under identical conditions it somehow does not.

Trouble is, each and every time these events have been subject to forensic analysis that can answer the question definitively simple higher than standard pressure was involved or some defect in the gun was present.

If someone can talk about a blowup without getting into the weirder theories it better helps to solve the problem.

Besides, jon’s case was intact. Even if you believe in unicorn detonation theories......nothing “detonated” here.

[243winxb]

In addition, the only way the gun can fire is with the locking bolt in the cylinder notch. If anyone can make the hammer fall on any revolver they have when the locking bolt is not in the notch that is the first I have ever heard of.
.

You need to read the old model Ruger Blackhawk instruction available on Rugers website.

Its very possible for the firing pin to hit off center of the primer. The cylinder is out of time and not locked.

Single actions need to be loaded a certain way.

Happened to me with a 44 mag, but luckly, the round didn't fire.

[35remington]

This gun under discussion is not a single action firearm. According to the owner it was in a good state of repair.

The off center bullet so obstructed by misalignment that it hit the frame is not plausible. The essentially predominantly centered firing pin strike also attests to that.

Very slightly off center, which is the most it could have been, will blow up nothing.

[funnyjim014]

Could the remaining parts be tested for hardness? No one seems to have mentioned anything more than just saying it's got to be bad

[35remington]

What round count has the revolver been exposed to?

[DCP]

That would be relevant if the conditions for “detonation” existed in the chamber of a firearm when a normal charge of powder was used. It does not.

The idea of “detonation” is that faster smokeless powder somehow explodes like dynamite every once in a while for utterly unexplainable reasons while somehow for the millions of other rounds that are fired under identical conditions it somehow does not.

Trouble is, each and every time these events have been subject to forensic analysis that can answer the question definitively simple higher than standard pressure was involved or some defect in the gun was present.

If someone can talk about a blowup without getting into the weirder theories it better helps to solve the problem.

Besides, jon’s case was intact. Even if you believe in unicorn detonation theories......nothing “detonated” here.

You're so close! S.E.E does not happen with fast burning powder. Only slow burning. I shoot a lot of gallery loads 3 to 4 grains of 700x even with a double charge there is not enough pressure to blow up your gun. I also called Lyman loading lab and talked to a tech to confirm this.

[kens]

I read that the case headstamp was impressed in the frame? This would indicate high pressure.
What does the headstamp of the case look like?
Is it smeared?

[BeeMan]

I am keeping additional comments in this thread, though it responds in part to information added to the other thread.

After reviewing SAAMI drawings, I am still staying with the primary cause as poor design but also adding that this failure is probably a due to a combination of factors. This turns out to be the case more often than not when I do root cause analysis on product and process failures.

Just because something can be done doesn't mean you should. Reaming out a 410 revolver cylinder to also chamber a 45 Colt is only advisable if the design is evaluated for the old chamber, the new chamber, and the interactions of the old and new. Minimum and maximum dimensions allowed per SAAMI for each clambering can go from a conclusion of 'looks okay' to 'warning bells are going off.' As a single dimension's example, the maximum diameter allowed at the front of the 410 SAAMI chamber can allow an off center impact on the barrel forcing cone if the bullet is off center. Statistically speaking, an off center impact is a matter of when, not if. One impact, in and of itself, may not be a problem. But rarely is a single factor out of spec in complete isolation.

Unless we can review design intent from the chamber reamer drawing and look at the as machined dimensions of the part that failed, there is too much room for tolerance stack to convince me that the cylinder design was not vulnerable from the beginning.

The questions about rotational mis-alignment due to bolt locking issues struck me the same as 35remington. Misalignment to a small degree is a given. More than one source said Colt revolvers locked up tighter than most, but that they also wore and required a smith's attention to stay tight. Forcing cones are the insurance for this characteristic of revolver design.

The question of hardness has been raised. The part does not look brittle to me in pictures. I would suspect it being soft if anything, and then unzipping once it initially failed at a stress riser or internal material defect.

Another question comes to mind: what was the bullet profile, size, and hardness? Roundnose, SWC, .452, .454, etc. The OP acknowledged a mix of purchased and cast lead, if I recall correctly. Which was in the chamber at the time? Probably small considerations and maybe not a factor at all. Hints can come from asking and answering all the questions though.

As far as the load pressure goes, I would de-emphasize the load pressure as a primary concern. The bore diameter ahead of the brass case likely allowed considerable blowby, based on SAAMI specs.

Last, as a matter of analysis, the question needs to be asked whether lead around the barrel interface is a cause of the event or a result of the event. Once parts started deforming, alignment was almost certainly out of spec so lead could have been deposited there because of misalignment. This all happens very fast but there are still ways to reconstruct the sequence.

BeeMan

[JBinMN]

I am no expert, but this pic from jonp( the OP) would not make me think it was a S.E.E..



I am gonna stick with my opinion that it was failure of the firearm due to faulty manufacture practice(s) until someone can provide more evidence otherwise.

BTW, in no way would I reload that case, as it was described to be in an earlier post.
IMO, That one is one for the wall or the recycler... Your choice though.

[243winxb]

For outside pressure to crush the case , the bullet made a stop before entering the forcing cone. Pressure spike. It also happens when the bullet moves out of the case to soon, from the firing of the primer. It sort of acts like a plugged barrel.

In a revolver, bullet jump is possible with light neck tension. The bullet moves forward, out of the case. Most times it keeps the cylinder from turning.

The recoil from thr OPs first 3 shots may have disloged the forth rounds bullet? With the 410 chamber length, its not going to keep the cylinder from turning.

[DougGuy]

I am going to attribute this KB to an obstruction in the cylinder itself. Somehow a boolit lodged in the cylinder, as in a squib load that may have enough felt recoil to not alarm the shooter, yet left a boolit in the cylinder. I don't think there was a double charge or even an overcharge of Unique. However, I often caution about using more than 10.0gr of Unique in 45 Colt caliber because it can be spiky and unpredictable. Even under the overcharge scenario, I don't think the gun would have been damaged like it was so I am going with an obstruction in the cylinder.

[edp2k]

Possible inclusion in the cylinder metal.