Why can glocks not shoot reloads?

[Clark]

Grump and BluesBear,
You guys gave me the 1,2 punch.
LOL

Excuse me, I have to go the Bermuda Triangle....

 

[Bruce Layne]

Two grains of Bullseye, finely ground with a mortar and pestil, wouldn't didn't blow up an 1892 Colt Navy chambered in .38 Long Colt. Of course I only loaded 50 rounds so I guess it isn't really all that scientific. The only damage to the revolver were a few small scratches on the grip frame from the vise.

As I've mentioned in previous posts, the most likely cause of an underload KaBoom is a small amount of powder (50% or so) suspended in air inside the case. In that situation, almost all of the grains of powder are exposed and can burn almost instantly. Half a powder charge lying on the bottom of a cartridge in a gun clamped in a vise is not the same thing as having the powder evenly suspended inside the case. Suspended powder can occur when a second shot is fired in quick succession, but the timing is critical. Fire too soon and the gun is still in positive g recoil and the powder is on the bottom of the case. Fire a little too late, and the gun is being pulled back down on target, and the negative g loading will put the powder on the top of the case. Not many people discharge a pistol at the top of the recoil arc, which may account for how rare these events are. Some powders are probably more likely to detonate than others. Your assumption about fine grained powders seems likely, for example.

My point here is that a static test can't duplicate the problem, which is probably the main reason that it hasn't been duplicated in the lab. The barrels used to derive pressure curves are not conducive to being quickly whipped about at greater than one g accelerations.

Single base smokeless powder is made with nitrocellulose. Double base powder is made from nitrocellulose and nitroglycerin. In some applications, each of these substances is an explosive. When they explode, they produce much more energy than they do when they're burned. In a gun, they are designed to burn quickly and not explode, and most of the time that's what they do. But is it so difficult to imagine that these explosive materials might explode under some conditions?

I think underload detonation is similar to the grain elevator explosions in some regards. There are combustible products in suspension, having a lot of surface area exposed to a very rapidly moving flame front or shock wave. There are differences too. In a grain elevator explosion, the combustible material requires the air around it to provide oxygen to support combustion and gunpowder does not. A grain elevator was not designed to contain high pressures that would support an increased combustion rate but a gun's chamber is capable of very high pressures intended to accelerate the rate of combustion.

Another analogy is the internal combustion engine. Gasoline vapors require added oxygen for combustion, but the cylinder was designed to contain mild pressures. Detonation is a problem that limits internal combustion engine design. Increase the cylinder head temperature or compression ratio, and detonation occurs. Detonation quickly destroys an internal combustion engine.

C4 is a powerful explosive when initiated with a blasting cap, but it's also possible to pinch off a small chunk, light it with a match, and use it like sterno to heat a cup of coffee.

There are numerous examples of materials burning in one context, and exploding with a violent release of energy in another context.

The principal reason some powder makers advise against using lower than mimimum loads is the concearn of insufficient ignition leaving the bullet in the barrel or forcing cone/throat.

That's certainly another valid reason not to undercharge a round. But the manufacturers often have very specific warnings about undercharges of specific powders. All powders would leave a bullet in a bore if sufficiently undercharged, but some powders are probably more likely to result in detonation than others. It certainly looks like the powder companies' recommendations are based on detonation concerns, not bullets lodged in barrels.

In our litigious society, most businesses are governed by liability issues, and that's probably more true of powder manufactures than most other companies. They're walking a fine legal line. Print a bunch of scary detonation information and advertise a product liability hazard, or don't say anything and be guilty of hiding a known or suspected product hazard from the consumer. They take the middle road. "Don't underload these specific powders. Follow the recommended load tables at all times." Not too scary, and no info for an attorney to use against them, but they've warned the consumer.

Did I mention that detonation in underloaded handgun ammunition is a myth?

Uhh, yeah, several times. You have expressed your OPINION that underload detonation can't happen at any time, just as I've expressed my opinion that underload detonation can probably happen under rare conditions that are difficult to replicate. Unfortunately, you and I can only have opinions at this point because we are working with a lack of data. I hate stuff like this, where there is insufficient data, and it's difficult to obtain the needed data.

The underload detonation theory seems scientifically plausible to me. There are a few credible events to support the theory as well, but detonation is rare and by its very nature the evidence is destroyed. So we really can't put a lot of faith in the case histories.

Faced with a plausible theory of the underload KaBoom, and some spotty real world evidence, I'm inclined to err on the safe side and say it's a possibility, and we should exercise caution to avoid adding another mysterious KaBoom to the case files.

Having opinions is easy. But actually PROVING something doesn't exist is usually very difficult. Most of the time, it's much easier to prove something does exist, and thus end an argument. But it's very difficult to prove or disprove the underload KaBoom phenomena. So we argue about it over the internet instead.

I'm an experimental sort of guy, but until someone can prove beyond statistical doubt that underload KaBoom does not exist for the powders, cases and bullets I use, I'll stick with the safer well trodden path. I'll be careful to avoid overcharges or undercharges because it's the prudent action. Not that I'm happy with these sort of fuzzy play-it-safe beliefs. I'd rather have hard data.

I don't have any need to intentionally undercharge a case, so it's easy for me to be cautious about underloading ammo. My goal is to ensure that my loads are all as consistent as they can reasonably be. I load nice, middle of the road target rounds. People wanting squib loads will need to decide the risk factors for themselves, and unfortunately that decision can not be made based on facts, only supposition and opinion. For anyone who wants small loads in large cases and is uncertain about detonation, maybe a reasonable precaution would be to avoid firing these loads when the gun is in recoil.

Incidentally, there is a nearly identical discussion about the existence or nonexistence of God that has been keeping philosophers and theologians arguing for centuries. Without hard data, it becomes a belief based largely on faith. Fortunately, I think we stand a better chance of eventually resolving the underload KaBoom question. But someone is going to have to do the right experiments.

 

[Grump]

Flame-resistant suit ON...

When they explode, they produce much more energy than they do when they're burned.

I'd REALLY like to see the physics behind that one. Is there some matter --> energy direct conversion going on here? Naw, we're just re-arranging molecules and atoms and a lot of light comes out when electrons change energy states. The amount of energy available to be released is largely fixed.

When nitro-anything breaks down into its higher-volume byproducts, how are you going to get MORE energy out of it?

Those who know metals--can 5 gr of nitroglycerine blow a .357 Magnum's chamber? Bullet weight should not matter in my estimation, because the wave front travels so much faster than for propellants.

Put 3 or more pounds of powder in a pile and subject it to high explosives, and maybe you'll get a detonation. Inside a cartridge case, no flame front can do it.

Here's your experiment: run smokeless powder in any fluidized-bed furnace using solid fuels like granulated coal or wood pellets. Fluidize the bed and light it up. Repeat 1000 times. Don't think it will happen, not even in a million. The chemistry and physics are against you.

Some theories are neat, plausible and wrong.

 

[Bruce Layne]

The amount of energy available to be released is largely fixed.

This is the fundamental argument behind the assumption that an undercharge can't damage a handgun. The assumption is wrong. There are two factors at work.

1) In an explosion, the energy is released in a much shorter time, and the peak pressure is MUCH greater. So even if the total energy was the same, less powder can definitely produce a much higher peak pressure.

2) An explosion is a different chemical reaction than a slower combustion process. I offered several examples trying to demonstrate this without a lot of complicated technical information. Whether the oxidation process uses atmospheric oxygen, or oxygen stored within the compound as is the case with explosives like nitroglycerin, it's possible for different reactions to take place depending on the amount of energy available. Burning is different from explosion. It seems reasonable to believe explosion could be more efficient, and burning could result in more unburned byproducts, and therefore less efficient combustion occured and less energy would be produced. Double base smokeless powders have various deterrents, as well as different grain sizes and shapes. These are techniques used to moderate the burn rate. Mixed with nitrocellulose, these compounds are too complex for an analysis in this forum. A complete understanding is probably beyond even the most learned theorists. Probably the only way to gain even an approximate understanding of such complex and nonlinear combustion processes would be through experimentation. It is certainly not as simple as burning a wax candle in an oxygen environment, assuming complete combustion, and calculating the energy produced.

Maybe another analogy would help. You can burn wood in a fireplace. The burning occurs at too low a temperature for creosote to combust. It vaporizes, travels up the chimney, cools, and condenses. However, if you burn the same wood in a forced air furnace, much higher temperatures are produced and the creosote burns. The combustion of the complex chemical stuff we call wood is more complete. More energy is produced by the more efficient combustion. If changing the temperature of a combustion process can change the combustion efficiency, certainly the much higher temperatures, and possibly the hypersonic shock wave of detonation might have similar results.

Even if the energy released is the same with rapid burning versus detonation, and that's a big if, concentrating that energy into one quick pressure spike is sufficient to explain the undercharge KaBoom.

Here are a couple of good places to read about nitroglycerin and smokeless powder. These are general sources of information, and aren't presented to support or deny the undercharge KaBoom theory.

http://www.ch.ic.ac.uk/rzepa/mim/environmental/html/nitroglyc_text.htm

http://www.speer-bullets.com/default.asp?s1=6&s2=14

 

[MrPhil]

God, save me from engineers. Give me an experienced technician anytime!

 

[Clark]

I have asked Hodgdon if detonation is a problem with reduced loads of
H110 in 44 mag and 357 mag. I have been told the only risk there is a
stuck bullet.


Ron Reiber, balastician for Hodgdon said, "I have never been able to reproduce this condition in the lab with a rifle with a new barrel, but I have been able to do it with a barrel chambered for an over-bore cartridge that has a rough throat, like, say, a .243 Winchester that has been fired 500 times. You need both the recuced amount of slow-burning powder and a rough bore to make it happen, and that combination can raise pressure so high it will lock a rifle bolt shut."


He goes on to say that he cannot do it with a fast powder like IMR4895 in any condtions.


So that would mean if the primer can get the bullet stuck in a rought throat, and then the 4831 burns, maybe, detonation will occur.

 

[BluesBear]

Suspended powder can occur when a second shot is fired in quick succession, but the timing is critical.

Do you really think you can fire a handgun fast enough to suspend the powder in mid air for a follow up shot?

Clark, I'll wager that you know as much as any person on the planet as to what will and won't blow up a handgun. Perhaps you can explain it better.

Grump said,
Some theories are neat, plausible and wrong.

I am going to have to save that quote. That's a keeper. It ranks right up there with;

Even if the other person is absolutely and completely WRONG, they've usually got a decently thought-out argument to back up their clueless posts (M.Irwin TFL 07-12-2001)

It would appear that for some, no explanation is required... for others, no explanation will do. (Baba Louie THR 09/29/03)

Sorry but I really don't care about or have time for stupid folks. Folks got a right to be wrong, stupid or both. (sm THR 05-06-04)

 

[Grump]

[Grump said the amount of energy is largely fixed] This is the fundamental argument behind the assumption that an undercharge can't damage a handgun. The assumption is wrong.

I beg to differ and any high school chemistry course will educate you out of your theories.

1) In an explosion, the energy is released in a much shorter time, and the peak pressure is MUCH greater. So even if the total energy was the same, less powder can definitely produce a much higher peak pressure.

Can we say non-sequitur, boys and girls? You can't refute the limited-energy fact by citing a higher peak pressure. Since pressure is a function of temperature and volume, and the volume is determined by the amount of "stuff" breaking down, a salt-grain's worth of the highest-pressure explosive _can't_, *can't*, CAN'T push any material past its elastic yield strength (or whatever it's called--I can mangle a syll-abble or two myself ) if the total energy available is not high enough. Believe it or not, there's a bit of a time-of-exposure element to guns blowing up.

But explosives aren't even measured by "pressure" of the fireball, contained-vessel or open. They are measured by their wave-front speed, detonation velocity or whatever. These are typically many times the speed of sound.

An explosion is a different chemical reaction than a slower combustion process. I offered several examples trying to demonstrate this without a lot of complicated technical information. Whether the oxidation process uses atmospheric oxygen, or oxygen stored within the compound as is the case with explosives like nitroglycerin, it's possible for different reactions to take place depending on the amount of energy available. Burning is different from explosion. It seems reasonable to believe explosion could be more efficient, and burning could result in more unburned byproducts, and therefore less efficient combustion occured and less energy would be produced.

How is burning different than an explosion? Oh, I remember now, you're using explosion and detonation interchangeably. They are not the same. Black powder is a 'low explosive" which is nothing more than a mix of chemicals which produce an idealized fuel-air mixture when heated beyond the activation level. The oxygen burns the fuels fast enough to cause a shock wave. No matter how you burn the stuff, it's making CO2, CO and whatever sulfur oxides. The difference in energy released in making CO2 and CO is negligible.

Smokeless and nitro are a bit different, being large, high-energy molecules that break down into exactly the same byproducts whether burned or detonated with adiabatic shock.

Ammonium Perchlorate is another large, high-energy molecule. It is commonly thought of as a mere oxidizer, O2 source, which does not explode absent the addition of a fuel to its breakdown reaction. However, that reaction releases energy. It will detonate if in a very large pile *and* subjected to adiabatic shock--with no fuel added. The gross amount of energy released in either situation is the same. A second huge danger comes from the release of hot, free O2 which can make a number of fuels do the non-detonation explosion thing, like grain silos do.

Only the most sensitive and unstable explosives can be made to detonate with a single small arms primer shooting a flame through a small orfice. For the ultimate test of your suspended powder theory, just take a chage weight of guncotton equal to your light pistol load, in single- or double-base as needed to replicate your chosen small-charge powder, and fluff it into a cartridge case. It will have several times the exposed surface area of your finest-grained powder, and will be porous enough to let the flame light the whole shebang very quickly. You'll get quite a pressure spike, but it will also drop so quickly that the bullet will not go very fast at all. And with between 2 and 5 grains charge weight, you won't blow any Glock or modern .38 revolver. It also won't detonate.

 

[Bruce Layne]

You can't refute the limited-energy fact by citing a higher peak pressure.

Sure I can. I'll use little words this time. I'll type slowly, so you can keep up.

Even assuming your incorrect assumption that a given amount of powder will release the same amount of energy regardless of how the oxidation occurs, the energy can certainly be released over a different amount of time. Making up reasonable numbers, this could produce 20,000 PSI in .001 seconds, or 100,000 PSI in .0001 seconds. Guns blow up when the pressure exceeds the designed strength, including the safety margin. A rapid pressure spike can exceed a pistol's chamber pressure rating when a slower burning charge of the same mass would not.

Since pressure is a function of temperature and volume

You are referring to Boyle's Ideal Gas Law. That only applies to ideal gases. It's a reasonable approximation when dealing with many gases. It is completely unsuitable to apply to burning or exploding gunpowder.

Oh, I remember now, you're using explosion and detonation interchangeably. They are not the same.

I didn't cherry pick these definitions. They were the first definitions for "explosion" and "detonation" provided by my web browser's online dictionary. The bold emphasis is mine.

Webster's Revised Unabridged Dictionary (1913) [web1913]

Explosion \Ex*plo"sion\, n. [L. explosio a driving off by
clapping: cf. F. explosion explosion. See Explode.]
1. The act of exploding; detonation; a chemical action which
causes the sudden formation of a great volume of expanded
gas; as, the explosion of gunpowder, of fire damp,etc.
2. A bursting with violence and loud noise, because of
internal pressure; as, the explosion of a gun, a bomb, a
steam boiler, etc.
3. A violent outburst of feeling, manifested by excited
language, action, etc.; as, an explosion of wrath.

WordNet (r) 2.0 [wn]

explosion
n 1: a violent release of energy caused by a chemical or nuclear
reaction [syn: detonation, blowup]
2: the act of exploding or bursting something; "the explosion
of the firecrackers awoke the children"; "the burst of an
atom bomb creates enormous radiation aloft" [syn: burst]
3: a sudden great increase; "the population explosion"; "the
information explosion"
4: the noise caused by an explosion; "the explosion was heard a
mile away"



Webster's Revised Unabridged Dictionary (1913) [web1913]

Detonation \Det`o*na"tion\, n. [Cf. F. d['e]tonation.]
An explosion or sudden report made by the instantaneous
decomposition or combustion of unstable substances' as, the
detonation of gun cotton.


WordNet (r) 2.0 [wn]

detonation
n 1: a violent release of energy caused by a chemical or nuclear
reaction [syn: explosion, blowup]
2: the act of detonating an explosive

It also won't detonate.

And once again, because you say so. As I've said before, there is no evidence to adequately support or deny the theory of undercharge detonation. It's a scientifically reasonable theory. Some case histories suggest it does happen, but there is no way to examine the results and be sure of the cause. In the absence of solid proof, it's prudent to follow the manufacturer's warning and not drastically reduce loads. If you did, you should certainly avoid raising a handgun quickly in a manner that could suspend the powder in the case and then igniting it.

If you want to rely on your own "expert" opinion, go right ahead. It's your gun, your hand, your eyes, etc. But please don't try to pass off your theory as a fact, just because guns don't always explode when undercharged. Someone may be injured because they're dumb enough to believe you.

 

[Grump]

Edit to add: This little theory *seems* to be disproven by all those 2.8-gr Bullseye loads that blew up revolvers in slow fire. Heck, even rapid-fire of 5 shots in 10 seconds leaves no time for the powder charge to be suspended in the air. These guys shoot at a 3.5-inch or so 10-ring at 25 yards. I suspect triple-charges, since they are all with reloads.

Even assuming your incorrect assumption that a given amount of powder will release the same amount of energy regardless of how the oxidation occurs,

So, are we bound by the laws of conservation of energy and matter in this arena or not? The chemical energy stored in those big molecules is known. They break down to the same component gases whether burned in the open, in a chamber, or detonated by the appropriate shock. The differences in energy released if the gases get broken down more "completely" or whatever can be predicted and measured on the chemical level.

You are referring to Boyle's Ideal Gas Law. That only applies to ideal gases. It's a reasonable approximation when dealing with many gases. It is completely unsuitable to apply to burning or exploding gunpowder.

Hmm... the apparent "explosion" from a propellant or an explosive is caused by high-volume gases suddenly being generated from much more compact molecules. This releases energy. Are you saying that "detonating" smokeless powder will produce a larger volume of gas than "burning" smokeless? The ideal gas law takes over for every molecule of gas that gets produced. A propellant adds more gas over a longer time than an explosive, but once it's a gas, it sure seems to follow the ideal law.

Otherwise, how does you flashhider work?

Have you studed enough explosives stuff to have even run into the adiabatic shock thing? Your list of common definitions is nice, but does not apply to the type of technical phenomenon you are theorizing. The powder-air mix inside a small-charge case is irrelevant. Your point appears to be simultaneous ignition of the whole charge at once because more surface area is exposed to the primer flame. It doesn't work. The only scientifically repeatable small-charge effects known to date are the chamber-ring problems of pistol powders in very large rifle cases--and I've never heard of that in any modern-steel gun. The pressure spike doesn't blow the barrel because there is not enough __**ENERGY**__ in there to do that much WORK. Too transient, the ideal gas cools off and pressure does too and regular old chemistry and physics takes over.

I'm done, thank you.

 

[Clark]

Is not the chance* of the shooter's body exploding into spontaneous combustion greater than achieving detonation in a pistol?






*I have no faith in UFOs, spontaneous combustion, big foot, Bermuda Triangle, global warming, cost effective mass transit in suburban situations, whole language teaching to read, Elvis is alive, power crystals, or magnet therapy.

--
A society that teaches evolution as fact will breed a generation of atheists that will destroy the society. It is Darwinian.

 

[caseydog]

Detonation has never been accomplished in a handgun by anyone trying to do it, not the powder manufacturers , not ammo makers , not gun manufacturers. Those theories sure sound purty, but have proven unduplicable.

Now dragging this thread kicking and screaming back on the topic :

Posted by Grump, Then there are all the law enforcement agencies getting Glock kB!s using fresh factory ammo. What's the theory on THAT one, eh?

Well , my theory is the marginally strong enough brass you already discussed AND a catostrophic deep seat caused by the lack of proper neck tension when the bullet bashes into the feed ramp.

This can be avoided by the using high loading density powders in the .40, 90% + is highly desireable not because of anything to do with detonation but because it self limits the deep seating problem. Ray

 

[Bruce Layne]

Detonation has never been accomplished in a handgun by anyone trying to do it, not the powder manufacturers , not ammo makers , not gun manufacturers.

I believe detonation is a relatively rare phenomenon, and nobody is trying very hard to replicate or study it. Why should they? The gun manufacturers void your warranty if you shoot reloaded ammo. The ammo manufacturers don't sell underloaded ammo. The reloading component manufacturers strongly warn against underloading or overloading, and insist you use the factory load data. They have a reason for this, and I suspect it's more than the deep seating issue, although that is also a problem. So is a bullet lodging in the barrel from an undercharge or firing only a primer, then following up with a full power round in an obstructed barrel.

Nobody thought the earth is round at first, but it is.

Nobody thought the earth rotates around the sun, but it does.

Nobody believed germs cause illness until they were seen under a microscope.

The entire medical community refused to believe that bacteria cause most ulcers, until a renegade doctor finally proved that most ulcers are caused by an H. pylori infection.

In short, history is a long series of people believing the current dogma, until someone forces them to accept the truth by proving it beyond any reasonable doubt. Even then, most people are very slow to abandon their false beliefs.

A lack of evidence does not disprove a theory.

I think the detonation kaboom theory sounds plausible and could explain some of the blowups that have been reported. We'll only know when someone does the right kind of testing. This will never be proven using heavy and stationary pressure test barrels. The theory involves a small suspended charge, as might happen in a rapid follow up shot under recoil. There is no test apparatus and no incentive for someone to look for this, even though a few isolated incidents suggest this is the actual cause of a kaboom.

Until this theory is proven or disproven, it's prudent to follow the powder manufacturer's warning and not underload less than 80% of a tested powder charge weight, or at least avoid rapid firing underloaded charges.

 

[tex_n_cal]

There have been extensive tests done by lots of folks trying to make "detonation" occur in pistols and rifles.

IIRC, Pressure "events" can occur with under-charges of slow burning rifle powder, in large capacity cases, however these are more like "excessive pressure" than "catastrophic" in nature.

There were some tests years ago done by NRA trying to make the famous .38 Special Bullseye load (2.7gr) detonate in labs tests. They never could make it happen, but they did note that a double charge of 2.7 gr Bullseye DID raise pressure to catastrophic levels, and was virtually impossible to visually tell from a single charge, when looking down into the case. They concluded that most cases of "detonation" were really double charges. For that reason I tend to stick with powders that bulk up better, that aren't easily double charged by accident.

As far as under charges of slow burning powders in magnum rifle cases, I see no real reason to try those, and I 100% weigh rifle charges anyway, so it ain't going to happen and I don't worry about it. I also enjoy my 10mm Colt for what it is, a ten shot .357 magnum, and I don't try to make a .41 magnum out of it.

There is a pretty decent looking waitress at the corner bar, flirty, foul mouthed, fond of substances licit and illicit, who's convinced she needs to loosen me up some. I would deserve every bit of the trouble it would cause me if I took her in, and I don't own Glocks, either.

In cases like the .40 S&W, they are susceptible to bullet setback in feeding, which is a problem with most commercial reloading dies. I turn the case expander down to .392, use a tight taper crimp, and have no problems with setback.

 

[Clark]

A lack of evidence does not disprove a theory.

I understand that, but I still don't believe in detonation with powders as fast as IMR4895, UFOs, spontaneous combustion, big foot, Bermuda Triangle, global warming, cost effective mass transit in suburban situations, whole language teaching to read, Elvis is alive, power crystals, or magnet therapy.


As a consultant, I get called when engineers get stuck. I have to ask them what they have done and what they believe without insulting them, and solve their problem in a reasonable amount of time. At the same time, I have to be listening for any unwarranted assumptions. One problem is considering a remote possibility that no one can replicate as important. One client had an engineer that thought aliens and relativistic effects were making the product fail. As in 90% of my work, once I convinced him to look at the problem in conventional terms and to try my solution, he came up with a better solution himself. Very smart and creative people can get stuck on a thought. Clean that out of their thinking, and they will get going again.

It is true I cannot prove aliens are not disturbing the night vision, but it is my job to get others to stop thinking that way. Of course those people are motivated to get their product working. On the internet, it is impossible to change the way anyone looks at things.

--
A society that teaches evolution as fact will breed a generation of atheists that will destroy the society. It is Darwinian.

 

[Bruce Layne]

As a consultant, I get called when engineers get stuck

As a consulting engineer, I too am called when other engineers are stuck.

One problem is considering a remote possibility that no one can replicate as important.

That is often a problem. So is discounting a valid theory that explains a rare event that causes serious injuries. I'm much more willing to play it safe and consider theories with less evidence when the consequences are so severe.

A society that teaches evolution as fact will breed a generation of atheists that will destroy the society.

I find it interesting what you are apparently willing to accept on faith without any credible scientific evidence, and what you are willing to discard out of hand when it has been observed and there is at least a reasonably plausible scientific theory. Of course, maybe your beliefs, like mine, are based on the serious consequences of not believing. In the case of the undercharge kaboom, it's the loss of an eye or some fingers. In the case of religious beliefs, it's that eternal damnation thing. That's the Blaise Pascal argument in favor of religious belief.

 

[Clark]

I go with the smart money.

I can believe an evolution teaching society will likely Self-Destruct, and believe in the power of prayer, all based on science.

But I still don't believe in detonation with powders as fast as IMR4895, UFOs, spontaneous combustion, big foot, Bermuda Triangle, global warming, cost effective mass transit in suburban situations, whole language teaching to read, Elvis is alive, power crystals, or magnet therapy.

There have been chemicals thought not to detonate, and we later found out that they will in large enough quanities. But guns have been around a long time, and no one can get repeatable pistol powder detonation in a pistol cartridge, and lots have tried.

 

[Bruce Layne]

It's OK to disregard the warnings of the powder manufacturers by undercharging your cases, and then pray for your gun not to kaboom. But please don't call it science.

In the interest of informed consent, if anyone is shooting your undercharged loads, I believe you have a moral obligation to tell them, "This is not factory ammo. I reloaded these rounds myself. I only used half the powder they used in the loads they developed and tested, even though they specifically warned that underloading to that extent is unsafe."

 

[grendelbane]

OK, while everyone is thinking of ka-booms, tell me why a pistol barrel would split in half.

It was my friend's SIG P220. When I say it split in half, I mean it separated into two pieces. A top half, and a bottom half. It split at approximately the 9 and 3 o'clock positions.

I have my belief about what happened, but would enjoy hearing others opinions.

Cartridge was a reload, 230 grain cast lead, with 231 powder. Not sure of the powder charge, but he is usually conservative.

I don't believe that it was caused by a reduced load.

 

[tex_n_cal]

It could have been a double charge, or it could have been bullet setback in feeding. Get a good digital scale and check the rest of the loads for unusual weight variations in the finished cartridges. Then check to see if the bullets are easily pushed back into the cases.

Those are the two most likely causes. It could be other problems.

 

[Grump]

It's OK to disregard the warnings of the powder manufacturers by undercharging your cases, and then pray for your gun not to kaboom. But please don't call it science.

As if the ONLY way for a reloading practice to be unsafe is for it to have a risk of KABOOM!!!

I have gone into undercharge territory with my eyes wide open and watching constantly for stuck bullets. No hole in my target=I check the bore. My shooting with such is also done 100% at temps above 80 degrees F.

Even assuming your incorrect assumption that a given amount of powder will release the same amount of energy regardless of how the oxidation occurs, the energy can certainly be released over a different amount of time. Making up reasonable numbers, this could produce 20,000 PSI in .001 seconds, or 100,000 PSI in .0001 seconds.

And what do you have to support your assumption that is stronger than my assumption? Have you even established that we are dealing with oxidation instead of reduction reactions?

Let's go to ammonium nitrate. With a proper initator, it will detonate--in the technical sense which relates to the speed of wavefront propogation. When heated in a more gentle "activation energy" situation, it breaks down into ammonium and nitrate groups. Explain to us how the total net Joules of energy released by these breakdowns is greater in the detonation than in the slower breakdown. The total "mole" quantity of atoms remains the same in either case... And at the end of the day, how is nitrocellulose or nitroglycerine any different?

Just to be clear, is part of your theory that suspending smokeless powder in an airspace will allow greater dispersion of a fuel in the atmospheric oxygen, resulting in catastrophically speedy oxidation of the fuel?

 

[Bruce Layne]

As if the ONLY way for a reloading practice to be unsafe is for it to have a risk of KABOOM!

I certainly never claimed that, nor implied that. We're discussing the kaboom issue. I'm simply advocating that an undercharge kaboom is reasonable from the sparse data, given a decent understanding of the chemistry and physics involved. I haven't commented about other unsafe reloading practices because so far, they don't seem to relate to this topic.

Explain to us how the total net Joules of energy released by these breakdowns is greater in the detonation than in the slower breakdown.

Did you miss the part of my post where I assumed that a given amount of powder produced the same amount of energy regardless of rate of reaction or other variables? For the record, I think it's likely that the energy release is approximately equal in the slow burn or the hypothetical detonation, but I do not believe it must be. There are certainly reactions where the same reactants form different products depending on factors such as temperature and pressure. When different products are formed, different amounts of energy will be consumed (endothermic reactions) or produced (exothermic reactions).

But again, back to my main point. Even if a detonation releases the same energy as a slower burning, if it is produced before the bullet can accelerate down the barrel, the chamber pressure spike will be very large, easily enough to split a chamber. We don't need to become sidetracked with the issue of a possible difference in energy. If the powder detonates instead of burning, a massive overpressure WILL occur.

Just to be clear, is part of your theory that suspending smokeless powder in an airspace will allow greater dispersion of a fuel in the atmospheric oxygen, resulting in catastrophically speedy oxidation of the fuel?

Just to be clear, I'll repeat myself. What I am proposing as a possible explanation for undercharge detonation seems more likely if the powder is suspended in the case, but it has absolutely nothing to do with the paltry amount of atmospheric oxygen in there. If suspended powder detonates, I think it will be caused by a large surface area. The chemistry and physics of detonation and even rapid oxidation are not perfectly understood. It seems likely that there are some nonlinearities in there that might explain why powder can detonate instead of burning.

Let's go to ammonium nitrate. With a proper initator, it will detonate

I think you've mentioned that before. I was not aware of that. I think it actually makes my case, to some extent. Most people think of ammonium nitrate as an oxidizer. Traditionally, to make an explosive, some fuel (a reducing agent) must be added. This is often fuel oil or diesel fuel. Then, it must be detonated with a high power explosive. So, when we hear that under some circumstances, ammonium nitrate can detonate, is it so far fetched to believe that a complex mixture containing mostly nitrocellulose and nitroglycerine can detonate? Detonations can be counter-intuitive, but I'd bet on nitrocellulose and nitroglycerine detonating before I'd bet on ammonium nitrate.

I don't believe I need to prove beyond a shadow of a doubt that detonation occurs in undercharged cases. That's a good thing, because there is not credible evidence that will prove that theory. If there was, we wouldn't be having this discussion. There are only scattered case histories that suggest it. But given a plausible theory and some isolated cases that suggest it's a real phenomenon, I think a prudent person would err on the cautious side and heed the powder manufacturer's strict warnings against undercharging. Not just the general "follow our load data" recommendations. Many powder manufacturers specifically warn against underloading at least some of their powders. They often cite 80% as the lowest safe charge weight. What do they know that we don't? When they issue such a specific warning, why would anybody want to disregard it?

 

[Grump]

Most people think of ammonium nitrate as an oxidizer. Traditionally, to make an explosive, some fuel (a reducing agent) must be added. This is often fuel oil or diesel fuel.

Lotsa theory, almost no homework. Ammonium Nitrate plus Diesel fuel is known as ANFO, for Ammonium Nitrate and Fuel Oil. The petrochemical is added solely to boost the power of the explosive. Without the fuel oil, AN is one of the few, if not the only, explosives that does NOT flash.

We can meanningfully talk more only when you understand these things, plus the need for adiabatic shock, and the differences between explosive detonation (in the explosives/chemistry realm, not the "bombs go boom" world of common dictionary definitions) and rapid deflagration. Then maybe we can talk about the mechanisms of initiating an explosion using the flame from a small charge of primary explosive laced with a fuel mixture.

My prior comment was concerning Ammonium Perchlorate. That one's more similar to Sodium Perchlorate, the oxidizer in non-mercuric corrosive primers, IIRC. AP is most commonly used as rocket fuel oxidizer. The pile of AP barrels I heard blow up one day was a series of fueled and unfueled explosions--the unfueled ones were triggered by shock waves, and NOTHING was suspended in the air for exposure to a flame front.

Still, there's been no answer to my observation that 2.8 grains of Bullesye in the .38 Special reportedly blew quite a few revolvers in SLOW FIRE.

Would this theory be disproven with a series of 100,000 shots fired, under vibration calculated to "fluidize" the charge in the case? I'd be satisfied with 5,000 firing cycles.

Any theory that cannot predict results is useless and may not describe the real world.

Name the powder manufacturer who will identify a blowup hazard from undercharging cases.

 

[Clark]

Thanks for the reply. You didn't do it yourself did you? If you're not able to reel off a series of alloy specs and other information it sounds like you may not fully understand the stresses which are involved in and around welds. There is a possibility you may have set up an area where stress will arise and later crack the weldment. If you had one surface bubble chances are you have more underneath, plus areas where the weldment is poorly attached to the substrate. Not to mention porosity which may be visible only by a change of polishing potential.

No TIG welding for me.
I paid to have it done, as I have dozens of times on guns.
Randy Ketchum of Lynwood Guns did it, and he rattled off a bunch of metallurgy that I forgot.

ANYWAY, I am shooting handload IMR max 44 mag loads in my 40 S&W Glock.
I feel like I have figured out the Glock Kaboom limitation and overcome it.
The weld is good enough.
Analyzing the weld would be getting sidetracked.

--
A society that teaches evolution as fact will breed a generation of atheists that will destroy the society. It is Darwinian.

 

[twolf]

Govt and Idiots in general

There are couple points I would like to make regarding the Glock and in particular .40 S&W Glocks.


1. If they were not safe to operate, law enforcement agencies would not use them in such great numbers.

2. I do know of someone that blew up their own Glock 23. They were using reloaded ammunition which they did not reload themselves. The guy they bought it from was not an expert reloader or even a novice. End result they bought reloads from a guy that did not know what he was doing and there weapon was destroyed because of it. Note: I've heard of people being killed by this type of event but the Glock held it's external integrity. Point being, they coudl have died but didn't because the gun was over-engineered for safety.

3. My department switched from S&W to Glock a couple years ago. When the Glcok representative showed up at the range, he has dragging a Glock 22 on a chain behind his car. He got out and took the weapon off the chain and fired it, it worked perfect.

The Glock is a wonderful weapon that can use reloads but you need to follow SAAMI specs. I've heard several say the Glock is not perfect and they are right. It was perfect for Gaston Glock cause he made it. My perfect weapon would be the Twolf. You see everyone has their own version of perfect!

Shoot straight and stay safe.