Another name for SEE?

[Jim]

Got an email from a good friend that has been shooting and handloading for decades. He watched a guy blow up a rifle the other day. He suspects PDS. I wrote back. "What's that?" He says "Propellant detonation syndrome". Gotcha. Another name for what we call SEE.

[Larry Gibson]

Jim

Difference is PDS has never beed replicated in a lab and is still theoretical. SEE Is not "propellent detonation" but basically an explosion caused by high pressure resulting from the bullet becoming a bore obstruction. It has been easily replicated in labs and is well understood.

BTW; I'll probably be able to call, as requested, later today or tomorrow.

Larry Gibson

[swheeler]

How about KBM(Kaboom) The only detonation I believe in is with Class A EXPLOSIVES not with flammables like smokeless powder.

[geargnasher]

I thought nitroglycerine was an explosive. :kidding:

BTW, gasoline isn't a class A explosive, but under the right conditions, can "detonate" with disasterous results to an engine.

Gear

[swheeler]

I thought nitroglycerine was an explosive. :kidding:

BTW, gasoline isn't a class A explosive, but under the right conditions, can "detonate" with disasterous results to an engine.

Gear

When it is used in smokeless powder it is part of a flammable, which is not a class a explosive

[firefly1957]

In Greener's book on firearms he shows a double rifle that had a black powder charge detonate he blamed it on the powder being to fine and detonating instead of burning. I have not heard much on this lately a lot of the early reports if I remember correctly were very light bullseye charges and slower IMR powders well below minimum charge weight.

[mroliver77]

Larry, can you point to any published material on labs creating SEE. I am not looking to disagree or start anything. I have never seen any "proof" of SEE being anything more than a theory. I am always interested in solid evidence proving or disproving any phenomena related to our passion. Plus I Really hate blowing myself or my guns up.;)
Jay

[Jim]

What I know about SEE or PDS wouldn't a thimble. I DO know, though, that the resultant pressure of a BP charge will go through the roof if the case density is less than 100%. Even at that charge, there's a potential for disaster. BP is best compressed.
On the other end of the spectrum, BP can be loaded to a very low charge and made to work. I have proved this(only to myself) by experimenting with such small charges in my Lyman .54 Plains Rifle.
The chamber in the rear portion of a Lyman GPR where the snail is attached is bored .360 to 1.00" deep. I got this data from Lyman. I calculated the charge to fill that chamber, loaded it and placed a patched .535 ball over it. That is not a compressed charge. I found it odd that the report was more of a sharp crack, like a modern firearm, than the typical boom.
I can only surmise that the small charge developed a high pressure and resulted in such report.

That's my story an' I'm stickin' to it.

[Jim]

the evil double post twin!

[swheeler]

Jim you got a studder there, 2 fer one deal! By golly that'll rack up the number of posts!

[Jim]

It irritates me. Makes me do twice as much typin'.

[felix]

Consider the insurance implication of a SEE condition done on purpose. A SEE occurs more often than any one realizes it. It is by pure luck NOT enough power is released on any one occurrence to cause significant concern by most shooters. However, there are some of us who have damaged guns by tempting fate. I have a gun using a designated load that will deliver a SEE every time when fired within the same constraints. The entire implementation was offered to a lab and was promptly declined. ... felix

[swheeler]

It irritates me. Makes me do twice as much typin'.

LOL you funny guy you

[Jim]

Felix,
I know no one that has more experience with this phenomena than you. I thought of you immediately when I received the email.
I distinctly remember the very long thread, years ago, when this was discussed. I am now convinced that what happened to me the other day was an example of SEE, or what my friend calls PDS.
Next time I get ready to play with light pistol propellant loads, I'm gonna place it with Kapok. That's what I should have done to start with but, I never thought SEE would manifest with a light load like that.
I was fortunate. The rifle didn't blow that time.

[swheeler]

Consider the insurance implication of a SEE condition done on purpose. A SEE occurs more often than any one realizes it. It is by pure luck NOT enough power is released on any one occurrence to cause significant concern by most shooters. However, there are some of us who have damaged guns by tempting fate. I have a gun using a designated load that will deliver a SEE every time when fired within the same constraints. The entire implementation was offered to a lab and was promptly declined. ... felix

And probably with a single base powder taboot, yes?

[35remington]

Jim, what Felix is talking about and what you're talking about ain't the same.

Light pistol powder "detonation" is the most doubtful theory of all, and isn't SEE.

SEE doesn't manifest itself with light pistol powders, so in that sense you're both correct and incorrect.

I have never, ever heard of a rifle "exploding" because a very small charge of pistol powder was used in it. Curiously, it seems to happen to revolver and automatic pistol shooters when another cause of the problem is much more plausible. We, unfortunately, tend to believe in conspiracy theories and the least likely explanation for problems when pistol powders are used.

If pistol powder in small doses in large cases truly caused problems, those guys using two to three grains Bullseye under a round ball in, say, a '06 or 30-30 case would have blown themselves up repeatedly in the space of time this new cast bullet board has existed.

No such thing has happened. One has to wonder why.

[leftiye]

I disagree. I think all of these thangs, SEE, PDS, Black powder detonation, chamber ringing, are the same phenomenon. I think they all depend on something that acts like a barrel obstruction (and that usually being a bullet) occurring . Sometimes, as in the black powder example it is the ball/boolit/bullet not moving Quickly enough as the explosion (yup, black powder is an explosive) then impacts the bullet as it fills the space that was left behind the bullet by this loading scenario. Chamber ringing with a case filler that is tamped over the powder leaving a space between the filler and the bullet.is another example. In the smokeless examples again the boolit/bullet is moved forward by the primer or primer and abortive powder ignition, and then the powder ignites in the space behind this bore obstruction.

[35remington]

The "fast powder blowup" theory differs quite considerably from what you state and shares very little in common with those other things mentioned. In this case those who believe in such things think that the powder somehow "over ignites" and blows up rather than propels even though the powder charge is extremely light.....and the fast powder doesn't have the necessary kinetic energy to destroy the pistol if it burned in any normal scenario, so an "explosion" is mysteriously posited. With ideas of this type you hear such internet terms as "flashover detonation" and similar folderol.

Chemists who make the fast pistol powders discussed tell us that the chemical composition and molecular structure of the powder cannot support an "explosion" and the arms that have been examined in such "blowups" always show signs of overpressure, which is distinct from that of an explosion. Analysis of the metals involved in "blown up" pistols have shown this distinction. Overpressure is due to overcharging. An explosion is a much faster event and will show up in the analysis.

So far, no dice.

No barrel obstructions are involved according to these theorists, nor does the bullet cause a bore obstruction. The powder speed is much faster than that involved in SEE. The bullet is seated normally and often is lighter than normal which results in increased case volume due to shallower bullet seating (see Cowboy Action Shooting claims and practice). The defining factor is somehow that "too little fast pistol powder" is used with "too much case space."

That's how the "fast powder detonation" theory goes.

You know.......they didn't do nuthin' wrong, like over charged a case multiple times.

I must make clear I'm referring to "detonation" of fast pistol powders only, and not to SEE or those conditions found with slower rifle powders.

[felix]

Yes, a single base powder....H322, early TBird lot. ... felix

Yes, even small pistol charges in small cases can go bananas when least expected. With revolters we would never know it because of the rapid pressure loss at the gap; With autos the moving chamber volume helps the reduction of pressure from recognition of a SEE. ... felix

[gravel]

since I had to search for the acronym........... SEE = 'Secondary Explosive Effect'



http://www.exteriorballistics.com/reference/glossary.cfm

[steg]

Thanks gravel, I was trying to guess what it was all through reading the posts.........................steg

[leftiye]

35 Rem, So, a small charge in a large case couldn't have a hangfire like progression resulting in very fast pressure rise that was acting against the immobile bullet? Whacha think has been happening to target revolters for about 40 years now? You know, the .38s with a wadcutter and 2.5 grains of bullseye.

[35remington]

The potential energy yield just isn't there. 2.5 grains of Bullseye, even if it were to explode (which it can't; the chemistry and molecule chains won't allow it) doesn't have the suds to get it done.

What I think has been happening in target revolvers is multiple charges. If there is room for more than one charge of powder in a case, and there most certainly is, it's going to get there at some time through error.

What's curious is you don't hear of 3.0 grains of Bullseye in an '06 case "blowing up" (and a true explosion should be able to gut a rifle as well). The reason for that may be that even a quadruple charge is not overpressure.

Not so with a revolver.

With fast powders and when positing fast powder "detonation", many still ignore that the powder manufacturers and load developers have never, ever run across a problem.....and Lyman listed loads of down to 1.5 grains Bullseye with lightweight 77 grain wadcutters in their manuals. Certainly there's a ton of airspace in a 38 Special case with that load. I've shot 2 grains Bullseye with a light wadcutter in 38 cases myself.

In what....ninety years of usage of fast powders in small charges we've never been able to identify a problem that could be reproduced under controlled conditions in all that time. With probably millions of rounds fired to date.

As I said, you have to wonder why. That's why some of the hypothesis on the matter is less than a learned, scientific conclusion.

I will probably go to my deathbed without hearing proof of "fast powder detonation." I wouldn't bet on the theory in Vegas. Too many long odds and ninety years of time against it.

Since a recoil operated automatic pistol cannot and does not unlock until the bullet leaves the barrel, there is ample time for an event, and very little pressure relief mechanism operating when the gun is fired. Automatic pistols can and do blow out their case heads, and much of the powder used peaks in pressure before the bullet has travelled very far....certainly the bullet is nowhere near the end of the barrel when max pressure is reached. Most of their issues arise with deeply seated bullets or in the case of the tupperware, an out of battery condition combined with generous tolerances. Double charges can be possible as well if the charge is light and the powder is compactly granuled.

[405]

No harm in excercising the brain in one of these hypothetical discussions. While I have no direct evidence of an explosive incident with firing small charges of fast powder in a revolver.... I certainly have been surprised by how much chemical energy is stored in those small charges. If that energy is released too quickly as in something like a "near explosive" event then I can see how it could easily diassemble a revolver. I take nothing for granted when it comes to that potential chemical energy- therefore reloading. Every time I pull the trigger on a small charge of a dble based pistol powder of say 3.5 grains under a 140 grain bullet I am surprised by the energy released. That makes me very aware of the chemical energy stored in say 30-50 grains of any smokeless powder under a bullet in a rifle..... regardless of what ANY lab says the pressure response and burn rate should be!!

I think a couple of things get mixed up in these discussions or interchanged by meaning. Aside from the obvious overcharge blowing up a revolver there is the bullet stop-go-stop kaboom theory where the primer forces the bullet hard into the forcing cone, the bullet stops, then the fractured, scattered cloud of powder particles behind it ignite.... kaboom. I think that is a different "kaboom" theory from the classic undercharge of very slow powder in say a large capacity rifle case... where a compression wave moves, at primer firing, forward thru the powder charge, fracturing some of it along the way. That wave hits the base of the bullet and is reflected rearward back toward the main powder charge which in turn is compressed and burns at a near explosive rate .... kaboom. That reflecting compression wave theory is the only one I know of that has been at least partially proven by one of the Scand./European labs- IIRC either Lapua or Norma. They were actually able to take a scan type photo image of it as it proceeded thru the powder charge and was reflected rearward by the base of the bullet. Also, that report stated IIRC that they could not duplicate that reflecting compression wave siuation predictably and that it appeared to be rare. I do not know if any further testing was done beyond that or of any conclusive determinations.

[35remington]

That's how the theories differ.....but the "bullet stuck in the forcing cone blowup" revolver thing is really related to poor bullet pull and W296/H110 powder used in revolvers, often those with generous cylinder throats and large barrel/cylinder gaps.

Extrapolating that to a much faster powder is a stretch. The pressure has peaked and dropped much earlier with a fast powder, well before the bullet completely leaves the cylinder. Positing that the pressure somehow almost "goes out" then ramps up stratospherically again with such fast powders is unlikely given how fast their pressure peaks and drops and assuming an unobstructed barrel and cylinder. If the bullet is free to move it's hard to see how that could happen with a small charge of fast powder.

It exactly explains how W296 causes problems when incorrectly loaded. Some of the problem might be in relating the two dissimilar events.

[Jim]

:veryconfu

[STP22]

The cause for SEE was covered in either Rifle or Handloader magazine a few years back...I forget which. It was reproduced in tests. Creighton Audette even wrote about it. In short, lower charges of slow burning powders with j-word bullets in the right circumstances will blow up a good rifle.

[Larry Gibson]

Larry, can you point to any published material on labs creating SEE. I am not looking to disagree or start anything. I have never seen any "proof" of SEE being anything more than a theory. I am always interested in solid evidence proving or disproving any phenomena related to our passion. Plus I Really hate blowing myself or my guns up.;)
Jay

It was published in Handloader #187 (Mystery Solved) quite a few years ago and is well understood now amoung ballisticians. I have posted it here before. A "search" may find it. If not PM me with your email address and I will forward a copy.

Larry Gibson

[Larry Gibson]

Also many years ago Federal and Hercules did an extensive study and tests to determine the cause for revolver bolw ups supposidly with 2.7 gr of Bullseye under the 148 gr WC in .38 Specials. Turned out it was caused by severe overloads on progressive loading machines, not by "detonation" of the Bullseye. 35 Remington is correct in that the chemistry is just not there. The old straight line CH progressive loaders were notorious for multiple charges in the same case, probably why they haven't been for sale for many years. Unfortuneately I do not have a copy of those tests. If I remember correctly the results were published in a LEO Journal because of the interest in PPC shooting with the aforementioned load and the use of the CH loaders by numerous agencies.

Larry Gibson

[405]

35rem and LG,
I agree with those assessments of the stop-go-stop revolver problem along with the study set of revolver blow-ups using the fast powders like BE as being most likely simple double-charges/over-charges. The stop-go-stop thing I was referring to has been attributed I think in part to the use of the slower, "magnum pistol" powders in revolvers. Also, analysis of strain gauge data on a wide variety of experimental loads once in a while shows that worrisome double spike of pressure in several different load/gun type applications- not just revolvers.

In the end, the precise definitions separating what is considered an explosion or detonation (SEE in this thread) from what may be confused with a simple over-charge/over-pressure with resulting gun structural failure, matters not a wit to me. Witnessing such events along with the resulting damage has convinced me that the difference may be simply academic. Conservative reloading, reading the warnings, staying within accepted parameters, paying attention and understanding published load data is probably the wisest practice. :)

[Larry Gibson]

405

Granted the difference is academic but understanding the true nature of such occurences helps us avoid them. By not understanding them we may well be going down a path that leads to them. I guess we could quit reloading/shooting all together and just avoid it entirely but I don't see (possible pun there) that in your future or mine:drinks:

Larry Gibson

[Bass Ackward]

Human error is a large factor, but I doubt the only one.

I think that metal fatigue plays a big role in the fast pressure syndrom. And when it let's go, all signs point to over pressure cause it WAS pressure that caused it to change shape.

And fast pressure curves are worse than a slow gradual increases. So after a few thousand rounds, is it that unbelievable that of the many handguns produced over time, there is some failure rate?

[Hardcast416taylor]

Thanks Gravel, For awhile there I was thinking I must have been sleeping that day in 1st grade when they were reading SEE spot run.....Robert:bigsmyl2:

[bearcove]

I vote on the human error or progressive loading machine malfunction. Possible that powder bridging in powder measure being the problem. I always use a powder measure, it seems. BUT my technique has a tap tap to make sure that the powder has dropped. I don't think a progressive machine cranked as fast as possible is doing this. So someone loading a pistol cartridge has a good chance of a double or overcharging a case. If that is the case then there is a case with a light or no charge. That is a possible obstruction.

I have always been careful about small charges, and have caught mistakes. I check with a light to try and see mistakes. Harder to do with bottleneck cases.

[jcwit]

The above is one reason I load cases in batches and all cases are given a check with a flashlight before seating a bullet. May not be the fasest way out there but in my opinion its safer.

Two rules when reloading. Stay focused. Don't rush, hurry or whatever you wish to call it.

[Jim]

The above is one reason I load cases in batches and all cases are given a check with a flashlight before seating a bullet. May not be the fasest way out there but in my opinion its safer.

Two rules when reloading. Stay focused. Don't rush, hurry or whatever you wish to call it.

I used to batch load. I got(let myself get) distracted one day doing that. When I got started again, about 10 or so rounds in, I thought I might better look at the charges. Sure enough, I had several doubles.
Now, I charge and seat one at a time. I'm just not in that big of a hurry to blow my hand off and get my face rearranged.

[felix]

"Chemists who make the fast pistol powders discussed tell us that the chemical composition and molecular structure of the powder cannot support an "explosion"...... 35Rem

These chemists have no real life experience. Consider the poor ignorant farmer who had all his grain all blown up in a silo through no fault of his own. These guys know "their" chemistry through the school of hard knocks. ... felix

[bearcove]

Ok, is it possible that a similar condition to the grain explosion is cause. Does old powder give off dust that might cause a explosion when stirred up by recoil from previous shots

[Jim]

With respect to powder dust, I've never seen it. I've heard from others that say they have. Powder dust and the resultant high pressure in ignition is why a lot of loaders suggest that loaded ammo not be tumbled. However(comma) I've been told by an ammunition manufacturer that their loaded ammo is tumbled prior to packaging to improve appearance.
I've been told by a small scale powder manufacturer(that had time to talk to me) that powder is plastic in nature and will not particulate. Earl Narramore also states this in his book "Principles and Practice in Loading Ammunition".
Hearsay is worth nothing and that's all I have to go on. I'm neither a ballistician nor a physicist, so I can't prove anything.

[35remington]

No real life experience? Really? They just design and manufacture powders for a living, and test the products in labs using calibrated pressure equipment in real cartridges. And have been doing so for 100 years. Apparently this has no relevance? Can anyone here say they are in the same line of work?

Those people that manufacture the fast pistol powders discussed know their powder's characteristics and capabilities, I dare say, far more so than any person on an internet discussion board. And they've shot a lot more ammo, too.

If they say the chemistry's not there, it's hard to pony up the bona fides on the same internet forum to say with certainty that they are clearly mistaken.

Given human nature is screwing up, it's more believable to figure on human error.

But then I've never been much on conspiracy theories and complex explanations that have not proven out in 100 years.

[Dframe]

One of the major powder manufacturers tried for a long time to duplicate the purported explosive effects of Small doses of fast burning powder in pistol cases (SEE). I believe it was Hercules but don't remember for sure. The down stroke is that in ALL cases the destruction was NOT caused by detonation. Detonation leaves clear evidence in the grain structure of the steel on the damaged gun. In EVERY case they were able to investigate, the cause of catastrophic failure was EXCESSIVE PRESSURE caused by double or even triple charges. While in effect potential for injury to the shooter is not diminished, the distinction between over pressure and detonation is very clear. Wish I could find that study at the moment but alas I've lost it.

[felix]

Detonation leaves clear evidence in the grain structure of the steel on the damaged gun. ...Dframe

I say change the steel of the gun and we have a new ball game. Grenades are made with a metal type that will fly apart easily, that is, with a metal that is not tough in the least, and again, that is, a metal with no spring back with the energy release speed supplied. So, are grenades designed to go into a SEE condition every time like typical small arm primers are? Any time one of our powders goes into a speed of burn exceeding that designed into the substance to burn, I define that situation a SEE occurrence and nothing more. Has nothing to do with blowing up a gun, per se. ... felix

[swheeler]

Maybe 15 years ago I had a near miss. I pounder the bolt open and ejected what looked about like a belted magnum case(except this was a rimless 06 family cartridge), primer was flattened out and huge. I was shooting reduced loads of IMR 4227, ignored a couple retarded ignitions, then a hangfire and SERIOUS pressure. First person I showed the case to immediately responded "double charge" I know it was NOT a double charge. I still load some 4227, but it always gets dacron filler now in rifle cases.

[leftiye]

Sounds like a really good idea to combine what Felix just said with including the double spike pressure traces. Them guns may have been double or triple charged, or maybe not.

There have been barrel steel tests done on barrels purposed for use with black powder wherein the barrel was plugged, then filled with black powder, and then the other end plugged, then the powder ignited by fuse. The result in that case was nothing more than a jet of smoke exiting the primer hole. I know of no instance where somebody has done the same with smokeless with similar results.

[runfiverun]

felix.
wouldn't/doesn't sharp case shoulders speed up the burn rate of powders? [it's been my experience it does, at least slightly]
at least once they start to approach 50k or so?
if so, then wouldn't that be considered a minor see event or see like occurence.
or at least wouldn't it be easier to reproduce in a straight walled sharp shouldered case.
[ i have never heard of this type of case having a problem]

[felix]

R5R, here we are talking about wave fronts. The more square the case is, the more likely a wave front can bounce back in phase towards the primer. This includes straight walled cases as well. Now, a moving wall, i.e., projectile, lessens strongly any wave propagating back and forth which can add, or accumulate, to one another with the same wave length. That would be required to increase the wave energy to an "igniting" amount in most cases (literally). The more square the case, and the closer the hard angled neck is, the probably of SEE goes up. Yes, powder burns faster because the primer has more effect in terms of heat and wave propagation. Lengthen the case and the probability goes back down. Include wave busting materials in the case, such as lots of powder, space filler plastic, et.al., and the probability goes down. You can never get away from any SEE condition entirely because the primer is an explosive (wave generator) by design. By the way, the Weatherby cornered necks are a very good idea. ... felix

[BOOM BOOM]

HI,
I have lost 2 rifles to SEE.
A 25/06 W/ 120 GR J BULLET, and a Lyman Manuel min. listed load of IMR 4320.
A 7MM/06 W/ A a 140 gr. j bullet and a Lyman Manuel min. load of IMR 4350.
A DOUBLE CHARGE WOULD HAVE OVERFLOWED THE CASE EASILY.
Remaining bullets were later pulled & charges weighted to check( when I could see with my R.eye, & feel w/ my hands again). All disassembled rounds were according to listed guidelines.
I do not load minimum charges anymore, I DO USE FILLERS IN RIFLE CASES WITH POWDER CHARGES OF RIFLE POWDERS OF LESS THAN 80% CASE CAPACITY.
I believe that SEE's do occur in rifles.:Fire::Fire:

[leftiye]

Yup, and tha sun do come up in the east.

[runfiverun]

felix,that is basically how i understand it too.

and boom boom's two examples fit the basic requirements you described.
low powder levels of a slow powder that [i believe] is turned into a fast burning powder by being broken down by the waves.
kind of like flour exploding.

[bearcove]

100% load density is sounding better and better.