Going KABOOM with undercharged loads?

[altitude_19]

Has anyone every actually done this on purpose to verify it happens as it's said to? Do you have video?
To believe is one thing. To understand is another.
I will never buy the line "We've never managed to make it happen in a lab but I SWEAR it's true!"
I hearken back to the days when "everybody knew" that soldiers in formation should break step before crossing bridges because the harmonics of that many boots in step with one-another would destroy the bridge. I'm sure that was in a field manual somewhere (like this business is in ABC's of reloading) and I'm sure there were lemmings-a-plenty to defend it without asking for proof (the Wisdom Gods of drill and ceremony wrote it just like the Wisdom Gods of munitions wrote the ABC's of reloading). But such a thing has never been proven and as such was eventually dismissed.
Now, I really want to get to the bottom of this one (and believe it or not haven't made up my mind on it). Anybody's personal KABOOM experience is irrelevent unless they did it on purpose.
So can ANYBODY please show me where somebody INTENTIONALLY managed to destroy a test weapon with an undercharged cartridge and succeeded?
PLEASE DO NOT CONTRIBUTE IF: You saw a gun blown up by accident and THINK it was due to an undercharge. That is supposition and irrelevant.

[Reload3006]

I think I will choose to take Winchester Olins word that WW-296 H110 will Kaboom. What would they have to gain by telling you not to under load it? I paid too much for my revolvers and Equipment and I like my hands and face too well to ignore the manufactures warnings. hey Call me a paranoid Idiot but Listening to the Manufacturer has not resulted in my loss of gun ammo or limb in over 40 years of loading.

But Its your life you gun do what you think is right.

[Mooseman]

It Can and has happened...read it for yourself.
http://www.reloadammo.com/liteload.htm

[para45lda]

And Mythbusters proved that a formation creates harmonic vibrations powerful enough to damage a bridge didn't they?

Wes

[milprileb]

Legend has the Krauts jumped without parachutes into snow banks in Norway
and all was well.

No thanks, and No... I won't test the Kaboom thing either.

[462]

Not too long, ago there was a discussion about secondary explosive effects, and a member posted some lab test results proving that reduced loads of slow burning powder can and will cause an SEE, if that is what you are asking about.

[newcastter]

Maybe this is a good suggestion for a mythbuster show!!! would put alot of arguments to rest.

[altitude_19]

And Mythbusters proved that a formation creates harmonic vibrations powerful enough to damage a bridge didn't they?
If I remember correctly, they disproved it altogether. Then again I did just hit 27...senility is hitting me pretty hard.

[altitude_19]

It Can and has happened...read it for yourself.
http://www.reloadammo.com/liteload.htm
I only saw a lot of stories of KABOOMs where the shooter POSTULATED that undercharging was the cause. Near as I can tell, that page has nothing about a successful, INTENTIONAL replication of the condition. That's what I'm trying to find. There's really no other way to prove the theory.

[stillkickn]

The OP didn't ask anyone to go out and test their own guns, he asked if anyone had proof. As a new guy to reloading I'm interested in this as well and did find the reading listed in post #3 to be useful but not proof. Laboratory proof.
It seems to me that one of the more difficult things for a new guy is to know all of the parameters to be safe. For example I read here that very light loads in large cases is dangerous. I also read that very light loads are a way to swage a barrel. The words light and large are not specific enough for a new guy. I load 18 grains of 3031 in 30-30 and to me that looks like a light load in a large case. Lots of volume left over. To further the conundrum in my mind, I consider using filler to keep the powder in place for more consistent burn, but I see this can cause problems as well...?
This hobby has lots of tribal knowledge and hidden gotchas so I appreciate everyone else's experience. Good question OP.

[waksupi]

Well, all the old timers, and powder manufacturers are probably wrong. You guys go ahead and do the experiments, and report back. Gotta choose if you are going to be bold, or old.

[220swiftfn]

I believe what the OP is referring to is the "Bullseye Surprise" which they couldn't replicate in a lab (but a double charge did the same damage)... As to his "I'm only going to believe you if you've done it yourself"..... By that reasoning the world is flat (I've never been in space.) What I can contribute to this is that an undercharge of Black Powder WILL cause a "Kaboom" of the detonation variety......

BTW, to see what harmonics can do, Google "Galloping Gertie"......


Dan

[stillkickn]

Waksupi - No one is looking for permission to do something stupid. Just the knowledge of why. As I read the information in these posts and the articles provided there seems to be room for other causes. As to the old timers and powder manufacturers being wrong? Who said they where wrong? That's exactly the experience I'm looking for. I agree with you on bold or old, that's why the question was asked.

[Reload3006]

When you under load a cartridge of certain powders you get into unpredictable areas. That is why Old timers and Manufacturers tell you to abide by certain parameters. For example you under charge a case and you stick a boolit in your bore then fire again most likely you get a Kaboom. Maybe you get a kaboom before the boolit sticks in the bore either way you are in dangerous water. Sometimes its better not to ask why kind of just like learning algebra dont question it until you have been at it for a while and then you will have the tribal knowledge too.

[smkummer]

Until I fixed my Lee powder charger on my Pro 1000, it would occasionally drop a under charge of either 700X or Unique in a 38 special case. These ranged from no powder to anywhere in between. I was happy when enough powder was present to push the bullet out the barrel. So out of 30-40 undercharges, nothing strange happened.

[Reload3006]

Well I suppose for all you unbelieving whippersnappers go out and commence experimenting. If you live through it give us old idiots an education. its never to late to learn.

[stillkickn]

Thanks Reload. The source of my question came partly from something I recently read that described using a grain or so of Bullseye to fire a cast boolit as a method of swaging the barrel. A very light load. I reread the the link provided above and see that the speed of powder burn is a big factor. The analogy of a grain dust explosion in a silo helps me understand why this would happen. So, do you think a grain of Bullseye to swage a barrel is safe?
I will try to find where I read this so I can provide it.
All of the posts about safety and not leaving known parameters are well taken.
Safe shooting.

[Bret4207]

If by "a KABOOM" you mean the Secondary Explosive Effect that is widely reported when using slow burning powders in large cases or the ringing of chambers form similar events, then yes, it has happened, been explained, tested and verified. Our own Felix Robbins, an actual, honest to God retired rocket scientist, has explained the SEE in detail several times. The ringing effect has best been explained in "The Modern Sheutzen Rifle" by Dell and Schwartz.

Your 18.0 3031 in a 30-30 case uses a medium burning rate powder in a relatively small case. If you were using 18.0 grs of H870 in a 300 Mag then yeah, you might well see an SEE! Plus, if that 30-30 you are using carries an RCBS 30-180FN for instance, that is going to intrude far deeper into the case than, say, a Lee Soup Can which sits waaaay up in the neck. All this stuff alters the case volume and pressure and burn rate, etc., etc., etc.

I suppose if you wanted to test it and had access to a barreled action of no value you could do it by chambering it to a nice big 300 Mag or 7mm Mag case and using a very slow powder. If you had something like Larrys Oehler PBL you could track the pressure curve and spike too. You might find it doesn't happen every time, but that when conditions are right it happens none the less. Lacking all that I'd stick to established safety guidelines from the powder manufacturers.

Powder burn rate chart- http://www.hodgdon.com/burn-rate.html

[Bret4207]

Oops, you were posting when I was writing. A very fast powder like BE is not likely to ever give you problems when used in small amounts, other than sticking a boolit in a barrel. If you want and accurate slug for barrel measurement, then you need to upset the slug in the barrel. Shooting a .308 slug up a .311 barrel will give you a slug measuring about .308! OTH, if you put the slug in the throat, upset it and drive it out you'll get an accurate idea of your dimensions.

[stillkickn]

Ya Bret, I don't see shooting a boolit as the most practical way to measure a barrel but did want to know if it was safe as it seamed contradictory. Thanks.
I will look for the Felix explanations of SEE as much of this is still beyond me but good reading anyway.

[milprileb]

Well I suppose for all you unbelieving whippersnappers go out and commence experimenting. If you live through it give us old idiots an education. its never to late to learn.


I totally agree but it would appear some folks got to learn the hard way.

I would submit though, this is like proving one can live through a rattle snake bite

..... :killingpc:killingpc:killingpc:killingpc:killingpc :killingpc

[M4bushy]

I think I will choose to take Winchester Olins word that WW-296 H110 will Kaboom. What would they have to gain by telling you not to under load it? I paid too much for my revolvers and Equipment and I like my hands and face too well to ignore the manufactures warnings. hey Call me a paranoid Idiot but Listening to the Manufacturer has not resulted in my loss of gun ammo or limb in over 40 years of loading.

But Its your life you gun do what you think is right.

Have you ever talked to someone at hodgdon about this? I have the info I was given is h-110 takes a certain amount of pressure to ignite. I was told if I down loaded it the worst that would happen is sticking a bullet int the barrel. They said the whole kaboom theory with a light load is a myth. Now who to believe, a hodgdon powder tech or Internet experts.
FWIW I decided to not take any chances with either scenario and use trail boss for light loads and H-110 for full power loads in my 480 ruger

[Reload3006]

Have you ever talked to someone at hodgdon about this? I have the info I was given is h-110 takes a certain amount of pressure to ignite. I was told if I down loaded it the worst that would happen is sticking a bullet int the barrel. They said the whole kaboom theory with a light load is a myth. Now who to believe, a hodgdon powder tech or Internet experts.

I have not talked to Hodgdon. I have however read the articles published by Olin WW296 about it. The main issue is unpredictability. (as I recall) it was published by Olin around the late 70z At that time Hodgdon was still a surplus powder seller. Not a manufacturer I don't know it to be true but H110 supposedly was a pull down of 296? at any rate they are the same powder today. Olin reported SEE and Fizzles therefore recommending that you not reduce the load at all to load ww296 as published only. I have several old WW reloading pamphlets It will be about a week but I will see if I can dig them up.
In the interim I would email Hodgdon if I were you before I set out to prove anything Or perhaps read what Felix has written

And You Sir are perfectly correct I for one would not take anyone's word for anything when it comes to safety. On line or in person. I would adhere to published data. If I had a ballistics lab where I could safely conduct experiments I may venture out into untested territory. But since I do not and I would assume that You do not. In the interest of safety my health your health not to mention the legal liabilities of this site that you follow the tried and true advice of load manuals that to include the Hodgdon site and printed material.

[M4bushy]

I have not talked to Hodgdon. I have however read the articles published by Olin WW296 about it. The main issue is unpredictability. (as I recall) it was published by Olin around the late 70z At that time Hodgdon was still a surplus powder seller. Not a manufacturer I don't know it to be true but H110 supposedly was a pull down of 296? at any rate they are the same powder today. Olin reported SEE and Fizzles therefore recommending that you not reduce the load at all to load ww296 as published only. I have several old WW reloading pamphlets It will be about a week but I will see if I can dig them up.
In the interim I would email Hodgdon if I were you before I set out to prove anything Or perhaps read what Felix has written

And Your Sir are perfectly correct I for one would not take anyone's word for anything when it comes to safety. On line or in person. I would adhere to published data. If I had a ballistics lab where I could safely conduct experiments I may venture out into untested territory. But since I do not and I would assume that You do not. In the interest of safety my health your health not to mention the legal liabilities of this site that you follow the tried and true advice of load manuals that to include the Hodgdon site and printed material.

After re-reading my post I wasn't referring to reload3006 as an "Internet expert" just making reference to all the info out there about light load kabooms.......

Ron

[MGySgt]

I hearken back to the days when "everybody knew" that soldiers in formation should break step before crossing bridges because the harmonics of that many boots in step with one-another would destroy the bridge. .[/U]

My last tour on Okinawa (89-90) there was a flat bottom roofed building that had a ramp running up to the top at Camp Kinser

Most units liked to use the top of the building as a turn around point. The formation runs over the years had damaged the internal roof of the building and chunks of concret was falling to the floor.

Other buildings built at the same time did not have this issue.

Was it because of the flat roof? Or the vibrations setup by the troops running in formation in step over a period of time?

The engineers did a test with a 40 man platoon running in formation on the roof - one circle of the roof and the equipment registered vibrations.

You be the judge - the roof was placed off limits for formation runs!

[Larry Gibson]

SEE has been verified by reproducing it in a lab/test facility. I have posted the Handloader article several times that expalins what SEE is, it's causes and how it happens. I have been involved directly with one SEE that destroyed a .280 Rem on a Mauser 3000 action. It is not a BS myth but there are a lot of myths surrounding it on how it happens. However, while most kabooms are the result of something mechanical (either in the load or the firearm malfunctions) the real cause is hunan error most often, whether we want to admit it or not.

A search of SEE should locate the article.

Larry Gibson

[mmorris]

Detonation was a common problem that most everyone who drove experienced before cars were equipped with a computer to control timing in response to "knock" on acceleration.

Detonation in an internal combustion engine is defined as the spontaneous ignition of the last three to five percent of the unburned gasoline ahead of the flame front that moves across the combustion chamber. Total combustion normally takes about 3 milliseconds, but this spontaneous ignition releases the remaining energy instantaneously, causing an intense pressure spike so short in duration that the piston cannot respond with faster movement. It instead absorbs this energy into the top of the piston, resulting in physical damage if continued long-term.

This "instant ignition" of the remaining unburned gasoline is possible because the air and fuel are well mixed and evenly distributed throughout the combustion chamber. I suggest that the gunpowder is more difficult to disperse as well as this phenomenon requires, which causes it to be difficult to duplicate.

A) You don't get more energy out of less powder. The damage is caused by the rapid rise in pressure that results from igniting the entire charge at once instead of igniting smoothly across the volume of powder. The same amount of powder burning slower than instantly will have a pressure curve, not a spike.

B) Pressure spikes are undetectable with a chronograph. Chronographs can detect pressure that is applied to the bullet long enough to add to the bullet's velocity, but pressure spikes are here-and-gone too quickly to impart velocity changes.

Mike

[Swampman]

I believe it's a myth created by those who have double charged and don't want to admit it. I will continue to believe that the rest of my life. There are powders like 296/110 that should only be reduced so much but that is a different thing.

[rasto]

I believe it's a myth created by those who have double charged and don't want to admit it. I will continue to believe that the rest of my life. There are powders like 296/110 that should only be reduced so much but that is a different thing.

You have to be a "lucky man" to have the luck of experience it :-(

Here you are my live through and no double charge at all.
I was punctually measuring every round on the digital scale and have a look what happened.


Here you are
http://img851.imageshack.us/img851/7261/img3363n.th.jpg (http://img851.imageshack.us/i/img3363n.jpg/)
http://img707.imageshack.us/img707/824/img3364zl.th.jpg (http://img707.imageshack.us/i/img3364zl.jpg/)

American Eagle (the flash hole was drilled as necklace)
There was no necessity do deprim the case after shoot because there was no primer!
I do not know the exact amount of powder but something around 17-18gr.
For somebody it is a myth but for me it is a very real thing

[Swampman]

There is nothing here to indicate that this was due to a light charge. So I'm unable to relate it to the topic.

[Mooseman]

Some people couldnt be convinced if it blew up in their hand...

[Cap'n Morgan]

I witnessed a SSE from a few inches away and still carries the scar as a reminder.

[M4bushy]

I believe it's a myth created by those who have double charged and don't want to admit it. I will continue to believe that the rest of my life. There are powders like 296/110 that should only be reduced so much but that is a different thing.

Those are my initial thoughts too. I've spoken to powder techs from Hodgdon and Ramshot both assured me it's a myth. I've also talked to some reloaders that have more knowledge about reloading than I'll ever know that fully believe SSE is real. I hope I never find out first hand what a kaboom is like, caused by SSE or double charge.



Ron

[altitude_19]

SEE has been verified by reproducing it in a lab/test facility. I have posted the Handloader article several times that expalins what SEE is, it's causes and how it happens. I have been involved directly with one SEE that destroyed a .280 Rem on a Mauser 3000 action. It is not a BS myth but there are a lot of myths surrounding it on how it happens. However, while most kabooms are the result of something mechanical (either in the load or the firearm malfunctions) the real cause is hunan error most often, whether we want to admit it or not.
I've searched and only found theoretical discussion (sound theory, I'll grant). Could I trouble you to find the article documenting the lab experiment?

[GP100man]

Me & a buddy done some crazy stuff with H-110 & a Redhawk chambered for 357 .

All we got was unburned powder & stuck bullets , most boolits would at least pop out the end of the muzzle .

& we found out ya can put enuff H-110 in a 357 case to cause it to slow down , I think it was compressed so much it hendered ign.

His revolver & idea ,I showed em the basics of straight walled cartridge loading .

He bought a Lee Challenger anniversary kit & with in 60 days bent his 8 3/8" 29 to the point it would`nt open !!

Yes he bought a manual , BBuuuttt- - - - -


It does`nt seem like it was almost 30 yrs. ago !!!!

[JIMinPHX]

When loading Blue Dot in a .357 mag, I've seen velocity go up as my powder charge was reduced. That spooked me quite a bit. I didn't go any lower with the powder charge after that. I did not want to reach the kaboom point.

[35remington]

Larry Gibson:

What lab or test facility, please?

I think we need to hear from them. Directly.

[Norbrat]

I believe it's a myth created by those who have double charged and don't want to admit it. I will continue to believe that the rest of my life. There are powders like 296/110 that should only be reduced so much but that is a different thing.

Explain how "that is a different thing"????

[Swampman]

Some people couldnt be convinced if it blew up in their hand...

I would be convinced it was caused by anything else other than a reduced powder charge. Reduced H110 and W296 will squib when reduced. That can stick a bullet in the barrel. Detonation from reduced powder charges is a myth.

[wv109323]

This was a "wifestale" in NRA Bullseye pistol. Ever once in a while some one would blow up a .38 Revolver and claim it was charge of 2.8 grains of Bullseye powder.
Hecules now Alliant could never replicate the event. Most were double charges or a squib load (leaving a bullet in the barrel) then a regular load.

[Bret4207]

I would be convinced it was caused by anything else other than a reduced powder charge. Reduced H110 and W296 will squib when reduced. That can stick a bullet in the barrel. Detonation from reduced powder charges is a myth.

The "wives tale" involves small charges of extremely slow burning powders in very large cases, not reduced loads of relatively fast powders in relatively small cases. I question the validity of the "double charge" theory when you consider this has happened in cases where a double charge would overflow the case. I think in some cases we don't understand the entire event and a lot of it sounds fishy, but in the interest of safety we need to err to the side of caution.

Here's one post from CE "Ed" Harris that mentions the lab test-

A main reason of S.E.E. is disorder of powder ignition. Powder charge does not burn after the explosion of a priming pellet. It smoulders like a German tinder, developing a cocktail of explosive gasses like nitrogen oxides, hydrogen (very reactive "In Statu Nascendi" hydrogen - not yet bound to H2 molecules), and carbon monoxide. When this highly flammable mixture of gasses catches fire from still smouldering solid powder remnants, may the "BANG !" be horrible. Mere three grains of gasses may literally wreck the strong .308 Win. rifle action. (Three grains of smouldered solid powder is still three grains of material, despite of it's gaseous form of existence).

Maximum allowed chamber pressure of .308 Win. factory-loaded cartridges is 3600 atmospheres. Case head stands 4000 atm. but the action may be hard to open and the empty shell is usually no more reloadable. Primer pocket may be enlarged and/or the primer blown. Pressure 4200 to 4500 atm. may blow the case head, and the action of many rifles stands as much pressure as the cartridge head; no more.

Severe hand and/or eye injuries of the shooter are possible if the action fails. Eye injuries, including the permanent loss of eyesight, are possible, when the case head fails. This depends on construction of firearm's action, but use of eye protection is always advisable when one is bustling with weaponry. Highest measured detonation pressure was 10 000 atmospheres. A pietzo-electric pressure gauge was broken and highest grade on the pressure scale was this 10 kilobars. A sturdy test-barrel of a German gun-proofing laboratory was wrecked, of course.

This disastrous test was repeated with another set of equipment for the sake of comparison. Pressures of first shots were slightly less than normal. It might be fifth or sixth shot, when the new test-shooting barrel blew up. Again a pressure gauge disintegrated and a scale told: 10 000 atmospheres! It was presumably just a fraction from whole horrible truth, because so called "wave pressure" of a detonation may exceed reading A HUNDRED THOUSAND ATMOSPHERES, when the explosive material is in gaseous form of existence, pre-heated and pressurized before explosion.

Caliber of tested cartridge was .243 Winchester, bullet weight 80 grains, powder then-new NORMA MRP, and the charge... surprisingly... just 15 % less than a maximum (compressed !) load. It was STILL A REDUCED CHARGE DETONATION; not one caused by an excessive charge, because the charge could not be excessive with those components in use. Light bullet and slowly burning powder is not an advisable combination of loading components for .243 Win., known as a caliber prone to S.E. Effect. (It's "big brother" .308 and "kid brother" .22-250 are considerably less risky; last mentioned presumably because of more steep 25 degrees shoulder angle).

Needless to say: All the loading components were examined carefully afterwards. They were faultless. Just the burning rate of powder was selected wrongly for the bullet weight. MRP powder is O.K. for .243 Win., but for the heaviest bullets of this caliber; weight 100 or 105 grains. For the most usual 90 grainer bullets is some more fast-burning propellant advisable.

Noted was a slightly less than a tenth of second lasting delay between hit of a striker and explosion. This same delay is noted also by survivors of S.E.E. accidents, if they can remember something from the "big bang". (Usual recollection is: "I squeezed the trigger and woke up in the hospital"). If the delay lasts a second or more, it is just an usual hang-fire, without signs of excessive pressure.

[NSP64]

Having survived a KABOOM with everything, but the rifle, intact, I will decline to try and do it again.
Light charge of IMR4227 in 270win, 140gr SP bullet. It was shooting fine until about 20th round went KABOOM. I have since read that lite charges in hot chambers might do this.

P.S. Took me two weeks to get the brass fragments dug out of my face. It seems that those holes in the action serve a useful purpose. My older Husqy didn't have those. And molten brass does not cauterize the wounds when it goes in.

[Reload3006]

this weekend I will try to find my loading pamphlets from Olin on WW-296. Alas I feel that its probably a wasted effort. Because some people will not believe anything until they kill themselves or someone else. I guess thats Darwinism in action. Hopefully these folks have not reproduced and polluted the gene pool.

[btroj]

I don't have first hand knowledge on SEE but will say that I don't use reduced charges of slow burning rifle powders. Not ever. Why take a chance?

As for powders like Bullseye, those are most likely double charges.

[Mooseman]

I would be convinced it was caused by anything else other than a reduced powder charge. Reduced H110 and W296 will squib when reduced. That can stick a bullet in the barrel. Detonation from reduced powder charges is a myth.

Well if you believe that then I say test it with your guns...and Ill stay away from you on the range.
If 296 and 110 will do it , so will others. Too bad we didnt have digital photos and computers back when we had Blown up guns come into the gunshop in pieces back in the 70's so I could show you proof.
Light load target shooters experimenting blew S&W guns apart with below min loads.
Had A Colt 1911 that bulged the chamber and barrel and jammed with a light load too.
Anytime you play with a controlled explosion stuff can happen...its why we rely on test data...and Manuals for guidance.

[fryboy]

even with common speed ( and commonly used ) powders such as unique light loads can vary pressure and velocity - you can prove this to yourself , merely load a cast boolit over a lite ( but safe ) charge of unique , before you fire point the muzzle upwards assuring that all the powder is against the primer , carefully lower and fire , now do it again but this time point the muzzle down until all the powder is against the boolit , raise slowly to keep the powder there and fire - now compare the chrony readings ...how can they be different you say ? after all it's the same carefully weighed charge hmmmmmm... now do a third one - holding the firearm level shake back and forth to level the powder against the bottom the the case and then fire ..what still a different reading ? how can that be ??? after all it's the same exact carefully weighed charge as in the other two but if you didnt just get 3 different velocities with corresponding different pressures my name is barry sotero ( and you voted for me )
and i agree with mooseman - if you're testing to make a gun go kaboom ( or even ammo loaded outside of listed aceptable charge weights - either end of the spectrum ) stay away from everyone at a range , i too saw a kaboom and the memory haunts me

[felix]

Those who don't believe in SEE occurrences have had sheltered lives. Any pressurized system having fluid/gas flow is a potential environment. Examples would be the previous engine knock explanation, and the noise contained within water pumps that sound like rocks are contained. We are just lucky a SEE does not go into the destructive state more often than it does. I guess there are a lot of folks who actually are aware of a very possible pipe hammering noise of hot water being turned on at their sink after a vacation, and then never looked into the matter further than offering a WHY statement. ... felix

[Larry Gibson]

Having survived a KABOOM with everything, but the rifle, intact, I will decline to try and do it again.
Light charge of IMR4227 in 270win, 140gr SP bullet. It was shooting fine until about 20th round went KABOOM. I have since read that lite charges in hot chambers might do this.

P.S. Took me two weeks to get the brass fragments dug out of my face. It seems that those holes in the action serve a useful purpose. My older Husqy didn't have those. And molten brass does not cauterize the wounds when it goes in.

Hmmmmm......let's see (no pun)......light charge of 4227 and obviously a lot of air space for the primer blast to blow over the 4227 before it ignited pushing the bullet into the throat/leade where it stuck........because of 20 rounds of such a low intensity load there was probably a lot of grit/fouling in the throat/leade........the 4227 then ignites and with a stuck bullet.....KABOOM!!!!!!

Classic SEE:-(

Larry Gibson

[Reload3006]

Hmmmmm......let's see (no pun)......light charge of 4227 and obviously a lot of air space for the primer blast to blow over the 4227 before it ignited pushing the bullet into the throat/leade where it stuck........because of 20 rounds of such a low intensity load there was probably a lot of grit/fouling in the throat/leade........the 4227 then ignites and with a stuck bullet.....KABOOM!!!!!!

Classic SEE:-(

Larry Gibson

But Larry they dont happen its a myth ..... :goodpost:

[Swampman]

It is a myth. Like I said folks need to blame something or sombody else. It's couldn't be human error on their part..........

[Swampman]

Well if you believe that then I say test it with your guns...and Ill stay away from you on the range.
If 296 and 110 will do it , so will others. Too bad we didnt have digital photos and computers back when we had Blown up guns come into the gunshop in pieces back in the 70's so I could show you proof.
Light load target shooters experimenting blew S&W guns apart with below min loads.
Had A Colt 1911 that bulged the chamber and barrel and jammed with a light load too.
Anytime you play with a controlled explosion stuff can happen...its why we rely on test data...and Manuals for guidance.


None of the things you mention reflect detonation....This is what we are talking about correct?

[swheeler]

Hmmmmm......let's see (no pun)......light charge of 4227 and obviously a lot of air space for the primer blast to blow over the 4227 before it ignited pushing the bullet into the throat/leade where it stuck........because of 20 rounds of such a low intensity load there was probably a lot of grit/fouling in the throat/leade........the 4227 then ignites and with a stuck bullet.....KABOOM!!!!!!

Classic SEE:-(

Larry Gibson

Looks like a good place for some dacron filler to be used. SEE not just for reduced loads of REAL SLOW POWDER anymore!

[M4bushy]

Hmmmmm......let's see (no pun)......light charge of 4227 and obviously a lot of air space for the primer blast to blow over the 4227 before it ignited pushing the bullet into the throat/leade where it stuck........because of 20 rounds of such a low intensity load there was probably a lot of grit/fouling in the throat/leade........the 4227 then ignites and with a stuck bullet.....KABOOM!!!!!!

Classic SEE:-(

Larry Gibson

Maybe a plausible theory but I still don't buy it!

[Mooseman]

It is a myth. Like I said folks need to blame something or sombody else. It's couldn't be human error on their part..........

Trolls seem to exist....I thought they were a myth.

[waksupi]

You guys go ahead and shoot this next season only using reduced loads of slow powders, and report back here in a year. Let us know your findings. There is obviously nothing to be worried about, and you can be known as myth busters.

[M4bushy]

You guys go ahead and shoot this next season only using reduced loads of slow powders, and report back here in a year. Let us know your findings. There is obviously nothing to be worried about, and you can be known as myth busters.

It's not the light loads, it's when people screw up and double charge the light loads.......;-)

[Larry Gibson]

M4bushy

It is not "detonation" that causes SEE it is the bore obstruction. Suggest you read the article (Handloader)[/I] that was posted. It is not a myth when it is reporducable and the effects are measureable before the KABOOM.

As swheeler mentions a dacron filler is best to use with 2400, 4227, 5744, 4198 and 4759 with reduced loads using cast bullets as it aides in ignition effeciency. Many get away without using the filler.....but some don't.

Larry Gibson

[Larry Gibson]

Larry Gibson:

What lab or test facility, please?

I think we need to hear from them. Directly.

Best I could find it was Dupont but am not sure. Who ever it is I doubt they will release any information otherwise it would have been identified in the article. I have experienced the exact same pressure spiking with my own 6.5x55 M38 when using 85 gr jacketed HPs and a slow burning ball powder. Fortunetely I am quite familiar with the Handloader article and was also measuring the psi and did not Kaboom my M36. I not longer use the 85 gr jacketed bullets with slow powders in the long throated M38.

Larry Gibson

[M4bushy]

M4bushy

It is not "detonation" that causes SEE it is the bore obstruction. Suggest you read the article (Handloader)[/I] that was posted. It is not a myth when it is reporducable and the effects are measureable before the KABOOM.

As swheeler mentions a dacron filler is best to use with 2400, 4227, 5744, 4198 and 4759 with reduced loads using cast bullets as it aides in ignition effeciency. Many get away without using the filler.....but some don't.

Larry Gibson

Aren't those all rifle powders? The op was about a handgun round. Apples and oranges.......there are myths of tightgroup blowing up big bore revolvers with light loads. 7.5 gr of tightgroup behind a 400 gr lead bullet is a safe load in my 480 ruger if I mistakenly doubled it 15 gr (still plenty of room in the case) I would expect a catastrophic event. It wasn't the light load in a large case, it's I screwed up.

[Larry Gibson]

This was a "wifestale" in NRA Bullseye pistol. Ever once in a while some one would blow up a .38 Revolver and claim it was charge of 2.8 grains of Bullseye powder.
Hecules now Alliant could never replicate the event. Most were double charges or a squib load (leaving a bullet in the barrel) then a regular load.

As a LEO firearms instructor I was privey to the Hercules test report at an instructor seminar I attended. They actually found a double charge with a deep seated bullet or a triple charge could Kaboom a K frame S&W (most common revolver used in PPC at the time).

Larry Gibson

[BruceB]

I'd also suggest that the non-believers read about the explosion of my wife's rifle. Ddo a search for "Karen moose" and you will find a thread titled "The day Karen Met The Moose".

Total destruction caused by ....well, go read the story.

I AM a believer, and I read the Stowers article in Handloader when it first came out. He was able to create the extreme-pressure conditions at will while REDUCING the loads.

[Larry Gibson]

M4bushy

It is not "detonation" that causes SEE it is the bore obstruction. That is what we find in the case here with 4227 in the 270 with jacketed bullets. The primer moved the bullet into a fouled throat/leade and it stuck there before the powder started to burn efficiently. The powder then caught fire and reached catastrophic psi before the bullet began to move. Suggest you read the article (Handloader)[/I] that was posted. It is not a myth when it is reproducible and the effects are measureable before the KABOOM. I too have discussed this with technicians and ballisticians from several of the powder manufacturers, and yes they all agree that “detonation” of smokeless powder is a myth. I also agree with them. However, as I stated, this is not about “detonation”, this is about a bore obstruction. Suggest you recontact those you have discussed this with and ask them if a bore obstruction can make a firearm go Kaboom. I think we all know what their answer will be.

The article by CE “Ed” Harris that Brett has posted is also real world and documented proof of SEE. Unfortuneately Harris uses the word “detonation” which is not the case. The evidence was there (“It might be fifth or sixth shot, when the new test-shooting barrel blew up) for the bullet to stick in the throat/leade as it became fouled but was not correctly noted. The more this phenomonum has been studied the more it was realized the “bore obstruction” was the cause. Simply compare the results to known bore obstruction kabooms and you’ll see they are identical.

In many cases of Kaboom I do not doubt "human error" as the cause. However, in this case all the elements for a SEE are there.

As swheeler mentions a dacron filler is best to use with 2400, 4227, 5744, 4198 and 4759 with reduced loads using cast bullets as it aides in ignition efficiency. Many get away without using the filler.....but some don't.

Larry Gibson

[Larry Gibson]

Aren't those all rifle powders? The op was about a handgun round. Apples and oranges.......there are myths of tightgroup blowing up big bore revolvers with light loads. 7.5 gr of tightgroup behind a 400 gr lead bullet is a safe load in my 480 ruger if I mistakenly doubled it 15 gr (still plenty of room in the case) I would expect a catastrophic event. It wasn't the light load in a large case, it's I screwed up.

Yes they are "rifle" powders but 2 of them are more commomly used in handguns. However, SEE is not weapon specific or even cartridge specific. SEE requires a set of circumstances be met regardless of the cartridge or the particular firearm type.

BTW; I did not read in the OP's first post that this was about handgun cartridges in handguns(?).

Larry Gibson

[Larry Gibson]

BruceB

Yup they all disbelieve.....until it happens. That was my case when I was in the ruination of a very good M3000 Mauser .280 Remington throated long for long seated match bullets..........Norma 205, lightweight varmint bullet...."proven worked up load" with magnum primers but didn't have anymore so use a standard CCI 200) .......1shot was ok....2nd shot had to pry open the bolt handle but neither of us gave it much mind as the load was "proven"....3 shot di the trick....fortunately John only got gas in his face and nothing else. Rifle was completely wrecked.

BTW that load was individully weighed out and filled the case to 1/2 of the neck....positively no chance for a double or triple charge. Obviously it was the change to the weaker primer that adversely affected ignition. All the SEE elements/conditions are certainly there.

Larry Gibson

[fryboy]

the one i witnessed was a 45 colt 6 shot revolver ( NOT a rifle ) my prior post list powder in 3 positions in the case - all of which will change the pressure/velocity - something you can check yourself or conveniently label a " myth" the direction you take as well as your deductions will be your own choosing , many people believe in god tho they have never seen him etc ... are those people wrong ? maybe maybe not but you cant prove it either way is this then a myth ? and all those blown up firearms are the result of nothing but operator error ? and double charges ? even the ones that happened with factory loaded ammo ( aka why some ammunition companies ever recalled some lots of ammo then is beyond me ... or suggested that light bullets and blue dot in the 357 magnum shouldnt be used ) eh it's all a myth just because you cant blow up your gun at will ........... brilliant simply brilliant and rather self serving IMHO

[M4bushy]

the one i witnessed was a 45 colt 6 shot revolver ( NOT a rifle ) my prior post list powder in 3 positions in the case - all of which will change the pressure/velocity - something you can check yourself or conveniently label a " myth" the direction you take as well as your deductions will be your own choosing , many people believe in god tho they have never seen him etc ... are those people wrong ? maybe maybe not but you cant prove it either way is this then a myth ? and all those blown up firearms are the result of nothing but operator error ? and double charges ? even the ones that happened with factory loaded ammo ( aka why some ammunition companies ever recalled some lots of ammo then is beyond me ... or suggested that light bullets and blue dot in the 357 magnum shouldnt be used ) eh it's all a myth just because you cant blow up your gun at will ........... brilliant simply brilliant and rather self serving IMHO

Is this ok?http://img.tapatalk.com/47f1d19a-bff2-6eec.jpg

[M4bushy]

BruceB

Yup they all disbelieve.....until it happens. That was my case when I was in the ruination of a very good M3000 Mauser .280 Remington throated long for long seated match bullets..........Norma 205, lightweight varmint bullet...."proven worked up load" with magnum primers but didn't have anymore so use a standard CCI 200) .......1shot was ok....2nd shot had to pry open the bolt handle but neither of us gave it much mind as the load was "proven"....3 shot di the trick....fortunately John only got gas in his face and nothing else. Rifle was completely wrecked.

BTW that load was individully weighed out and filled the case to 1/2 of the neck....positively no chance for a double or triple charge. Obviously it was the change to the weaker primer that adversely affected ignition. All the SEE elements/conditions are certainly there.

Larry Gibson

If you changed a component it isn't a proven load anymore!

[waksupi]

It's not the light loads, it's when people screw up and double charge the light loads.......;-)

I guess you can try that in your experiments. Double charge a light load of slow powder, you would MAYBE get up to a normal load, without overflowing a case.

[felix]

Larry, the word detonation has a funky definition/implication. Nothing starts and stops at the same time. If so, the big bang theory can be absolutely true making the time dimension irrelevant. There would be no expansion or contraction of the universe and its elements contained within. We know elements are created and destroyed within a time domain. ... felix

[M4bushy]

Yes they are "rifle" powders but 2 of them are more commomly used in handguns. However, SEE is not weapon specific or even cartridge specific. SEE requires a set of circumstances be met regardless of the cartridge or the particular firearm type.

BTW; I did not read in the OP's first post that this was about handgun cartridges in handguns(?).

Larry Gibson

After doing more reading on the s.e.e. phenom I see we are talking about two different issues. The issue I thought you were talking about is light (but in the book) loads in large case handgun cases with powders such as tight group. The example the tech at Hodgdon gave me about this is. "if we could get more energy out of the powder than we put in, we would be in the power business instead of the gunpowder business.

If I understand correctly, the S.E.E. phenom is basically obstructing the barrel with the primer charge wedging the bullet then touching off the powder charge causing a huge pressure spike in the chamber. Correct?


Ron

[Reload3006]

that is one possibility. also understand that when you fire a round it goes bang but there was not an explosion. there was a very fast burn that caused high pressure to fill the case / chamber of your fire arm. The laws of physics says that the pressure will follow the path of least resistance therefore the bullet leaves the barrel instead of breaching the chamber.
Now if that pressure spikes before the bullet can start moving as in an explosion the bullet does not have time to start moving before the metal of the chamber is breached. in a smaller scale of course but none the less explosive and very high pressures. Now the same thing happens in flour mills sugar mills saw mills anywhere a burnable or fuel source is mixed with the proper amount of oxygen you have the recipe for an explosion. or a very fast burn. with the net result being the same.

[fryboy]

Is this ok?http://img.tapatalk.com/47f1d19a-bff2-6eec.jpg

actually it was with 125 grain hollow points , you'd have to ask their engineers why that particular combo ended up being bad juju , they posted a blurb about it and advised against it and if you care to look at their data ( like you did to pull up the 110 grain page ) you'll note that the 125 and 135 grain bullets DO NOT list a blue dot recipe and the bullets bracketing those weights do have a blue dot recipe but what do they know after all ..remember supposedly it's just a myth ....

[fryboy]

i would edit for add but eh try this link ( since whatever anyone states seems to hold no merit because we're not a accredited lab )
http://thefiringline.com/forums/showthread.php?t=303766

"ATK Commercial Products
900 Ehlen Drive Anoka, MN 55303
www.atk.com
July 25, 2008
Dear Functional Wholesaler:
Please distribute this letter to all of your customers immediately with instructions for them to do the following:
• Post this letter in a highly visible area of their establishment
• Distribute to their customers as soon as possible
Alliant Powder Blue Dot® Product Safety Notice
Alliant Powder® periodically reviews and tests their published reloading data to verify that recommended recipes have not changed over time.
During the latest review Alliant Powder discovered that Alliant Powder’s Blue Dot® should not be used in the following applications:
• Blue Dot® should NOT be used in the 357 Magnum load using the 125 grain projectile (Blue Dot® recipes with heavier bullet weights as specified in Alliant Powders Reloading Guide are acceptable for use).
• Blue Dot® should NOT be used in the 41 Magnum cartridge (all bullet weights).
Use of Blue Dot® in the above cases may cause a high pressure situation that could cause property damage and serious personal injury.
We apologize for any inconvenience that this may cause and appreciate your understanding and cooperation in this matter.
Thank you for your cooperation and if you have any questions or concerns please contact me at Dick.Quesenberry@ATK.com or call me at 540-639-8503.
Dick Quesenberry
Alliant Powder
Product Line Manager"

i guess they prefer to merely err on the side of caution ? ( and less lawsuits etc ?? )

http://www.alliantpowder.com/getting_started/safety/safety_notices.aspx

[Oreo]

This is an interesting subject & I thank all of you who have taken the time to share your knowledge & post articles. Consider me one reloader possibly saved by having read this thread in time to avoid a problem.

I have noticed "something" when loading .40sw & 10mm reduced loads of WSF, (& maybe Longshot) trying to make low-recoil rounds for new shooters. Testing the loads I discovered most functioned predictably but occasionally I'd get a round that felt & sounded very different in a scary sort of way. I can't know exactly what was happening, & I'm not above considering loading errors on my part but I can say I don't have this issue with any of my other loads. Something was up with that particular recipe. Having read this thread I'll not be making anymore rounds like those.

[Larry Gibson]

If you changed a component it isn't a proven load anymore!

Well duh!!! Had I known then (early '70s) what I know now..........:groner:

Larry Gibson

[Larry Gibson]

After doing more reading on the s.e.e. phenom I see we are talking about two different issues. The issue I thought you were talking about is light (but in the book) loads in large case handgun cases with powders such as tight group. The example the tech at Hodgdon gave me about this is. "if we could get more energy out of the powder than we put in, we would be in the power business instead of the gunpowder business.

If I understand correctly, the S.E.E. phenom is basically obstructing the barrel with the primer charge wedging the bullet then touching off the powder charge causing a huge pressure spike in the chamber. Correct?


Ron

Now you are catching on.

Larry Gibson

[Larry Gibson]

Larry, the word detonation has a funky definition/implication. Nothing starts and stops at the same time. If so, the big bang theory can be absolutely true making the time dimension irrelevant. There would be no expansion or contraction of the universe and its elements contained within. We know elements are created and destroyed within a time domain. ... felix

Explosives "detonate". Progressive powders (even the fastest) burn. Engineers know that as do ballisticians. If progressive powders "detonated" at all you would need an explosive license to handle and store them. Progressive powders may indeed burn fast but they do not detonate. For example; there is absolutely no way that 2.7 gr of Bullseye under a 148 gr WC has enough energy within the powder itself to cause enough pressure to wreck a K-frame S&W, just isn't enough physically stored energy there no matter what kind "theories" or "hypothosis" we may dream up.

Larry Gibson

[altitude_19]

If I understand correctly, the S.E.E. phenom is basically obstructing the barrel with the primer charge wedging the bullet then touching off the powder charge causing a huge pressure spike in the chamber.
HOW is that even possible? Isn't that charge DESIGNED to move that bullet down the barrel? Pressure is raised out of limits when you attempt to ignite a charge to send a bullet down the bore? The bullet in the barrel is a resistance the cartridge is specifically assembled to overcome, isn't it?

[Mooseman]

Actually , Explosives BURN at different rates but usually very fast , but even they do have a limit. I Have dealt with explosives both military and civilian types and Put on Large Pyrotechnic shows years ago. I hope the below explanation explains what happens as how it can relate to gunpowder charges for firearms...

Low Explosive
An explosive which utilizes chemical formulas which combust when a certain amount of initial energy is applied to them. Most fireworks, with the exceptions of large salutes, fall into this category. The rate at which the pyrotechnic composition burns is mostly dependent upon the rate at which the composition can transfer heat from one layer of itself to another. When a composition's rate of reaction is very slow, it is known as burning. Examples of a pyrotechnic composition which "burns" would be a star in an aerial shell, flares, or gerbes. Burn rate is also highly dependent on pressure and temperature. Therefore, when a pyrotechnic composition is confined, its burn rate is accelerated. When the reaction is sped up drastically due to increases in pressure and temperature, such as the case with the burst charge in an aerial shell, it becomes explosive, and is known as deflagration. In an aerial shell, the temperature and pressure build up while the composition inside of it is burning. Once the pressure from the hot gases created during the reaction reaches a certain point, the casing will fail, rupturing outward, giving an explosion.
High Explosive
A device in which the explosive composition will detonate once initiated. High explosives can be initiated in several manners. The one that concerns us the most in the case of fireworks is deflagration to detonation. An example of this process is seen in large (or confined) quantities of flash powder. One ingredient in flash powder is aluminum. Aluminum is known for it's ability to transfer heat and it's high heat of reaction (thermal energy produced when it combusts). Since the rate at which a pyrotechnic composition burns is dependent upon how well it can transfer heat, this is a very important property. Once ignited, the flame front in flash powder reaches supersonic velocities, thus creating a shock wave in the composition. Once a shock front is accomplished, the rate at which the composition burns is no longer dependent on how well it can transfer heat (as in the case of a low explosive). The burn rate is now dependent upon how well the explosive composition can transfer the detonation wave (shock wave) through itself. A salute must be large enough to allow for a shock front to be formed in order for a detonation to occur. This means a minimum amount (critical mass) of flash powder must be used to achieve detonation. Confinement of the flash powder in a salute lowers the amount of flash powder needed. A detonation releases a great amount of energy in a very short period of time, hence the reason salutes are much louder and have a "sharper"(caused by the shock wave) boom.
Gunpowder is Nitrocellulose based which is a nitroglycerine relative which is what ?An EXPLOSIVE !
Gunpowder does have other chemicals which by formulation control the burn rate , but, The burning rate of smokeless powder increases with increased pressure. The flame a primer puts out will come out the end of a rifle barrel, and if it fires over the top of a layer of gunpowder it ignites More surface area than it actually would with a fairly packed case. Primers are powered enough to push a bullet into the rifling where normally the pressure continues to rise in milliseconds on a curve but , it is a start of the curve and then a sudden spike of pressure that causes the High Overpressure problem and that tests the strength and elasticity of steel. If the steel can't handle it, you have Catastrophic failure like a grenade.
If you load a percussion Muzzleloader with smokeless pistol powder do you think it will hold together ? Will that Colt Walker handle a small load of 296 , H110, or unique ?
Deflagration...It is a risk I am not willing to take...
ANY time you fire a round you are dealing with a controlled explosion and high pressures because a bullet or Boolit wouldnt work otherwise.
The advice I use is Respect it, keep within Known Limits, and always pay attention to every detail when dealing with any Powder/cartridge/ or explosive.
I still have all my fingers and eyes so far.
Please Be SAFE Guys.

[Swampman]

It's not the light loads, it's when people screw up and double charge the light loads.......;-)

Correct.....

I believe guns blow up because folks make mistakes. I just don't believe in detonation as defined by modern magazine writers.

[Bret4207]

HOW is that even possible? Isn't that charge DESIGNED to move that bullet down the barrel? Pressure is raised out of limits when you attempt to ignite a charge to send a bullet down the bore? The bullet in the barrel is a resistance the cartridge is specifically assembled to overcome, isn't it?

Picture yourself sliding a large, heavy object across a floor. You get it moving and then the edge catches a nail sticking up. What happens? You come to sudden stop and the energy you are using to push the object stalls and builds. If you were me you would likely throw your back out right about then too!

Make any sense? A normal burn of the powder results in a relatively smooth pressure curve. An abnormal burn gives you an abnormal pressure spike. Given the right circumstances it can give you problems.

[Bret4207]

Correct.....

I believe guns blow up because folks make mistakes. I just don't believe in detonation as defined by modern magazine writers.

Then why do you doubt the professional ballisticians and powder company engineers that use sensitive laboratory grade test equipment to research this stuff that say, "DON'T DO IT"? I'm as much of a cynic when it comes to wives tales as anyone. But calling an event a double charge when it wasn't is just being stubborn.

[felix]

Larry, the government has full control of definitions. So be it. My primers just burn fast according to the licensing ops of the government. I'm lucky enough to be allowed to store them. The earth is flat by government decree. ... felix

[Swampman]

Then why do you doubt the professional ballisticians and powder company engineers that use sensitive laboratory grade test equipment to research this stuff that say, "DON'T DO IT"? I'm as much of a cynic when it comes to wives tales as anyone. But calling an event a double charge when it wasn't is just being stubborn.

It may not be a double charge but it wasn't detonation either. The reason ballisticians and engineers say don't do it is unrelated to detonation. It has to do with squib loads that can lodge a bullet in the barrel.

[stubshaft]

I have been handloading since 1967 and have shot almost every shooting game there is from smallbore 4 position, highpower, trap, skeet, benchrest, ipsc, ppc, pins and of course hunting. I have expended countless thousands of reloaded rounds in these endeavors and have not witnessed nor have met anyone who has actually been a witness to an actual SEE event. I have seen many guns with split barrels, blown out topstraps, slides and barrels destroyed, bulges and ringed chambers which were caused by overloads, firing the wrong cartridge, using some form of dacron/kapok wad, using powder with the wrong burning rate (garands).

Is there such a thing as SEE maybe, but I am not going to lose sleep over it.

[Bret4207]

It may not be a double charge but it wasn't detonation either. The reason ballisticians and engineers say don't do it is unrelated to detonation. It has to do with squib loads that can lodge a bullet in the barrel.

Wow, okay Mr. Stubborn, so the tests conducted in a lab where the ballisticians and engineer types were using a pressure test barrel are flawed because there was a bore obstruction froma previously fired squib? And, you are sure of this how?

Sorry man, but just because you don't want to believe something didn't happen doesn't it didn't. There were a whole lot of people that believed Bill Clinton when he said "I did not have relations with that woman, Miss Lewinsky". They were wrong too.

[MBTcustom]

If I ever get my hands on a ohler shooting lab, I swear with my hand on the Bible I am going to test this with a sacrificial rifle (amongst other things of interest like how much pressure It realy takes to blow up a Rem 700 action) Curiosity is killing me but without the $6000 dollar lab it is anybodies guess what is actually happening.
Personally, I believe SEE is a real thing and that it happens under specific conditions. It seems logical. In the mean time, Anybody got an Ohler lab for sale cheap?

[rasto]

Swampman I wrote you my experience and I can guarantee you that no double charge caused the problem.
I was making them one by one so no possibility of mistake.

[Larry Gibson]

goodsteel

I have the Oehler Personal Ballistics Lab and SEE is not a "guess". SEE is real regardless that some have not personallu observed it or whether some just may not believe it.

Larry Gibson

[Larry Gibson]

Larry, the government has full control of definitions. So be it. My primers just burn fast according to the licensing ops of the government. I'm lucky enough to be allowed to store them. The earth is flat by government decree. ... felix

felix

I'm not trying to change your opinion on whether progressive powders "burn" or "detonate" but consider this; gun cotton and dynomite, 2 explosives, were both tried in guns. Neither was successfull because the detonations could not be adequately controlled. Progressive burning powders on the other hand are quite controllable because they do not "explode" or "detonate".

Larry Gibson

[Reload3006]

with the best laid plans there is enough to go wrong with out inviting disaster. For me I choose to stay in the published guide lines of tested loads from reputable sources. If one wants to play mad scientist and go kill himself or maim someone else after fair warning from countless sources then I guess that is Darwinism at its finest. When you argue with and Idiot you have 2 Idiots arguing. All I can say to anyone who doubts the powder manufacturers SAMMI and countless other Labs who have all reported the SEE phenomena then I suggest they go and kill themselves what more can be done.
What really bothers me the most is a young inexperienced reloader with little understanding reading this foolhardy advice and they go out and blow themselves up.

[felix]

That's mo'betta', Larry! It's the definition/measurement of time that screws up most scientific endeavors. We don't have the required equipment to measure small durations/distances between two points in time/space. Consider the problems of folks like us using ordinary chronographs! Those sensors are most critical in such apparatus. ... felix

[altitude_19]

countless other Labs who have all reported the SEE phenomena
Funny how I still haven't seen you name one of these "countless" labs.

[altitude_19]

SEE is real regardless that some have not personallu observed it or whether some just may not believe it.
Personal experience has no bearing on a discussion geared toward discovery of laboratory-generated evidence. PLEASE stop trying to inject personal experience into the mix (unless you've recently video taped yourself destroying a rifle with an intentionally downloaded cartridge that was assembled in front of the camera, that is).

[altitude_19]

Wow, okay Mr. Stubborn, so the tests conducted in a lab where the ballisticians and engineer types were using a pressure test barrel are flawed because there was a bore obstruction froma previously fired squib?
WHAT #$%&^ LABORATORY???!!!! All I want is to find that laboratory! You seem to know so tell me! MY KINGDOM FOR THAT LABORATORY'S/BALLISTICIAN'S NAME!!!!
Seriously, generalities are less than helpful. Steer clear of 'em, k?

[waksupi]

Does it help that I am the CEO for the Rocky Mountain Ballistics Research Laboratory?

Did you know that Lyman has this site listed for reference?

By the way, your attitude needs a bit of adjustment. Cool it down.

[altitude_19]

Does it help that I am the CEO for the Rocky Mountain Ballistics Research Laboratory?
Only if you've replicated this condition in the lab. Have you?

Cool it down.
Noted. Been on night shift too long. My people skills are suffering.

[1hole]

"countless other Labs who have all reported the SEE phenomena

Funny how I still haven't seen you name one of these "countless" labs. "

Maybe because it's too few labs to be counted? :mrgreen:

A lot of labs are reported to have tried to duplicate it but I know of none who have been able to do so. Not saying such a KABOOM is impossible but am saying that while we can prove a positive, it IS impossible to 'prove' a negative. I mean, we can prove something has occured but we can't possibly prove something has never occured in the course of human history.

[MBTcustom]

Blowing up a firearm on camera doesn't prove anything either. That's why I mentioned that I would like to do such a thing just to see what the breaking point is. I honestly suspect that most modern firearms can take pressures in great excess of what most of us think of.
I think it is very possible that SEE could happen and be chalked up to heavy powder charge etc etc.
I believe it makes sense. Saw dust is not an explosive substance but if it is suspended in the air, it can flash (ie burn much more quickly). (You can test this for yourself by drizzling fine sawdust over a flame. It is impressive.) I think that part of the problem with the lab tests, could be that the test guns are so rigid. If you slam a cartridge in a gun and drop that gun onto a sand bag and take a shot in short order, the vibrations in the barrel, might be enough to get the powder in the case to "float" like the sawdust. Its just a theory of mine, but I wonder, because no lab would duplicate that specific characteristic of a sporting firearm in their test gun.
altitude_19, I'm a little confused by your insistence on laboratory tests. A laboratory is nothing more than a controlled environment. For the purpose of this test, the only environment that needs to be controlled is what is in-between the primer and the crown of the muzzle. What difference does it make to that environment, if the guy making the test was wearing a white coat or a pair of overalls? None.
If the test was only able to be replicated within a specific temperature range, you would take issue with the results right? So the fancy temperature controlled environment of a lab is of no use. Might as well be in a back yard. In fact it would add credence to the theory if it could be replicated in the field every time, you refuse to acknowledge their experience and insight.
You insist on an action being blown up on camera. That sir, is the most ridiculousness, unscientific, requirement I have heard of. The theory states that a rise in pressure is detectable, not that it blows up guns. I held a savage 30-30 the other day, that had only one locking lug. There is no way that it will handle the same pressure that a Weatherby bolt gun will.
At the end of the day this will be in the form of a pressure reading made by someone with testing equipment and you will have to take their word for it. Even when it has been revealed to you what many of the rest of us already know, that you have been talking to the experts the entire time, you refuse to acknowledge their experience and insight.

Personal experience has no bearing on a discussion geared toward discovery of laboratory-generated evidence.
Really, is that so? Why would you trust the experience of a laboratory technician over that of these veteran re-loaders? Experience is everything! It just needs to be well documented by an unbiased source who Knows what he or she is doing. S.E.E. could kill the guy who experiences it two inches from his face in a lightweight testing apparatus. That naturally lends itself to unbiased opinion.
Frankly, your disregard for the opinions expressed here is insulting. Almost everyone here is either an expert, or is working on it.
However, I think that new scientific experimentation is in order.
Please forgive my hard words and flame me if you must.
I know I'm being abrasive but your arguments got my goat something fierce because you are asking for scientific proof but you are not being scientific or cordial with the way you ask for it.
I take issue when people think that a man in his garage cant be just as certain of his findings as a man in a Lab, even though the guy in the lab is able to make a faulty assumption just as easily as the guy in the garage. I work for a company that makes space hardware, and you would not believe the stupid things I have seen.
Why dont you do some research of your own and post your findings for the edification of castbooliteers?

[MBTcustom]

Check out the plots on this page. They show a very clear second pressure signiture after the first one. If that happened in a barrel you would have kaboom......maybe.
http://shootingsoftware.com/pressure.htm
Pay special attention to "Nosler 7 STW factory load" read the explanation to the side of the picture, scroll down and see ".223 Rem- 40gr V Max Moly".
Now remember, S.E.E. this is just a myth. Totally unreproducible in laboratory tests.

[Bret4207]

More info-


DEFLAGRATION, EXPLOSION and DETONATION:

Three rates of exothermic disintegration

by John R. (Austria)

As you know the guncotton has (nearly) 3 nitro groups (NO2) per cellulose molecule (guncotton is a really extremely long molecule and therefore it is not exact stochiometric). These nitro groups are from the nitric acid used in the nitration process. Nitroglycerol is the ester of nitric acid and glycerol. Guncotton, Nitroglycerol and all the other higher nitro compounds are in their pure form "high power explosives". That means they are able to detonate. A detonation is by far more powerful than any explosion.

For example black powder is impossible to detonate. What happens when black powder is ignited is following: The fine sulphur and charcoal particles start burning, the generated heat decomposes the potassium nitrate (it gives off pure oxygen "in nascent state", as a very reactive free oxygen radical) and so the combustion of the "fuel" gets faster and faster. When the gaseous reaction products are not able to "fume off" the pressure and the temperature in the containment will rise quickly. When the pressure goes up and reaches a point where the container can't hold more it will explode. Note: The explosion is nothing more than a very rapid expansion of high pressurized gas.

Nitroglycerol is in its pure form a colourless oily liquid with no odour. When you put a few drops on a stone plate you can ignite them with a lighter. There will be nothing dangerous, just a nice flame but no detonation or explosion. Put 1 - 2 (no more than that!) drops on an anvil (wear ear and eye protection) and strike them directly with a hammer: extreme loud and powerful detonation! All the higher nitro compounds or nitric acid esters will react similar when treated that way. But what's now the difference between detonation and explosion?

Well: these "high explosives", as they are called in the literature, all have large amounts of chemically bonded oxygen in the molecule. If the amount of energy given to the explosive is not too high it will start burning. This is called a "deflagration". A greater mass of burning high order explosive can be very dangerous as it sometimes can go off in detonation from one moment to another with nearly "no reason". When more energy is given in a very rapid way (blasting cap) to the explosive, detonation immediately starts. This is when the molecular structures break up and enormous amounts of chemical bonded energy are set free by the decomposition of the nitro groups. The rest of the molecule can be seen as "fuel" that reacts immediately with the oxygen from the nitro group delivering even more energy. In some high order explosives the detonation zone moves with a velocity of up to 8500 m/s through the explosive!

The explosives molecules hit by the detonation front are smashed to ions and extremely reactive radicals ("loose" atoms; not yet bound together to be molecules like H2 or O2) and the whole thing gets plasma-like. Pressures go up to unbelievable 100 000 and far more atmospheres! Another fact that is difficult to understand but very characteristic for detonations is that the reaction products move directly to the detonation zone.
mausexpl.jpg (8893 bytes)
Every material (also - and especially - the hardest steel) is "atomized" to fine particles when hit by this detonation wave. When the detonation is over and no explosive is left, there are lots of reaction products (mostly H2O, CO2, CO, C, H2 and N) left. What follows is the explosion (rapid expansion) of the reaction products. Comparing black powder with dynamite is like comparing an airgun to a high power rifle.

NC powder consists of high order explosives with additions of phlegmatizers. The theory is that the phlegmatizer is like a shield between the explosive molecules that slows down the heat transfer and therefore the reaction. Usual NC powder is a mixture of highly nitrated cellulose and low-nitrated cellulose. Highly nitrated guncotton contain ca. 13 % by weight nitrogen, while low-nitrated collodion wool contain ca. 11 % N. Guncotton is almost insoluble in the usual volatile powder solvent, mixture of ethyl ether and ethyl alcohol while collodion wool is completely soluble, making syrup-like colourless liquid known as collodion. Mixture of nitrated cellulose is moistened with a volatile solvent when NC powder is produced. When the solvent is vaporized away, the powder contain "hairs" or fibres of insoluble guncotton in the plastic-like "matrix" of dissolved and hardened collodion wool. A solid powder kernel looks like composite plastic. The very first plastic, celluloid, was actually dissolved (gelatinized) collodion wool with some camphor added to make celluloid as elastic as the natural ivory, and less brittle.

American brothers Hyatt invented celluloid in 1869 for billiard balls and piano keys as an artifical ivory, which was easy to compression mould. In the original NC powder was a matrix itself the phlegmatizer or shield between more explosive fibres of insoluble guncotton. There were also some inorganic salts like potassium or barium nitrate added into old NC powders giving more oxygen and "cooling down" deflagration of the powder. Some old "semi-smokeless bulk shotgun powders" had those inorganic salts only as the phlegmatizer. Mixture of guncotton, collodion wool and salts was compressed to become thick sheets, like cardboard. The sheets were then grated to become irregular grains and rounded in a rotating "candy drum". Just the surfaces of bulkpowder kernels were gelatinized by spray of solvent to make them smooth and less prone to imbibe humidity from ambient air.

Semi-smokeless shotgun powder is older invention than "dense" or gelatinized smokeless rifle powder. Prussian artillery captain Schultze invented nitrated sawdust of alder wood, impregnated with potassium and barium nitrates, in 1864. The "sawdust powder" was too strong medicine for artillery pieces, but it became soon popular as a shotgun powder. Captain Schultze established his powder plant to the country of shotgunners, England. German Max Duttenhofer discovered the first practical semi-smokeless military rifle powder in 1884. This Rottweiler Cellulose Pulver was nitrolignine & nitrocellulose mixture, nitrated brown charcoal of alderwood, but it was thoroughly gelatinized.

Frenchman Paul Vieille invented a more stable gelatinized smokeless rifle powder in 1886, a mixture of guncotton and collodion wool, containing no more nitrolignine. Russian chemist Dimitri Mendeleyev discovered the optimal ratio of soluble and insoluble grades of nitrocellulose (with nitrogen content 12.6 %) in 1890 and "the Mendeleyev's Principle of Controlled Deflagration" in 1891. Swedish Alfred Nobel and Britons Abel and Noble designed powders like Ballistite and Cordite in the late 1880s by use of nitroglycerol as a solvent of nitrocellulose. The original mixture was Gelignite or gelatinized dynamite with up to 60 % percentage of nitroglycerol - a high explosive - but just a slight addition of some organic phlegmatizer like "mineral jelly" a.k.a. Vaseline is able to tame the shattering detonation to become a controlled deflagration. British Rifle Cordite Mk.1. contained 58 % nitroglycerol.
vsop.jpg (15028 bytes)

Detonation wave may become reflected and focused like light. "Shaped charges" of armor-penetrating warheads or mines were designed just before 2nd World War and applied for armor-piercing during WW 2. Hand-carried (portative) shaped blasting charges were first used by Germans in 1940 for capturement of besieged French Maginot Line strongholds. Principle of shaped charge was discovered by American powder chemist Munroe in 1880s and improved by German Neumann in early 1900s, but military applications came several decades later. Shaped charge may be a very simple design, like this "V.S.O.P. Bomb", loaded into a wine or brandy bottle with a concave bottom. Conical shape of bottom cavity is most efficient for production of a narrow (focused) axial "detonation jet".

Versatile general-purpose powder VihtaVuori N310 is TRULY versatile, but ANY easily flammable handgun/shotshell powder with 4000+ Joules per gram of calorimetric energy is applicable. Blasting cap must be powerful enough to produce detonation. Advisable is to use bundle of three caps, bound side-by-side. Distance between bottle bottom and surface of object intented to penetrate should be about equal with diameter of a bottle. More or less distance or a direct contact on the object shall produce less successful "focus" of detonation wave and the jet of molten or atomized glass. Perforation through 50 mm thick steel plate is recorded (or at least rumored). Detonation of common smokeless powder is able to release all the Infernal Forces: Just a nuclear warhead is more destructive. (Drawing and caption by PT).


Under "special" circumstances most smokeless powders can be detonated. The development of modern shooting powders was a long and very dangerous way. Finding the correct manufacturing process of smokeless gunpowder was often a trial-and-error method and many guns blew up because of wrong powder "design", or wrong dosage of correct design.

French chemist Paul Vieille, inventor of first practical smokeless rifle powder was able to explain nature of detonation in late 1800s, but the comparison between detonation wave and light was discovered by German mathematician Bernard Riemann already in 1859. Many times the scientists are predicted inventions much earlier than existing technology has offered the means to realize their theories. Example given: French scientist Sadi Carnot predicted arrival of Diesel engine in 1824. First prototype of Diesel engine was assembled in 1895.

John R.

[altitude_19]

Really, is that so? Why would you trust the experience of a laboratory technician over that of these veteran re-loaders? Experience is everything! It just needs to be well documented by an unbiased source who Knows what he or she is doing. S.E.E. could kill the guy who experiences it two inches from his face in a lightweight testing apparatus. That naturally lends itself to unbiased opinion.
I'll concede this point. Poor choice of words on my part. But I'm still waiting for that thorough documentation by an unbiased source. I said this to try to weed out people submitting their own kabooms and CONJECTURING that the cause MUST have been an undercharged load.

Frankly, your disregard for the opinions expressed here is insulting. Almost everyone here is either an expert, or is working on it.
First, this is an unquantified statement. What is your standard for "expertise?" What percentage of members here have attained it? And just how much latitude should it buy me if I'm "working on" becoming an expert? Actually, I'd prefer not to read the answers to those. Second, opinions are meant to be taken to heart or disregarded at the discretion of the recipient. That's why they're free. Don't get your feelings hurt.

Please forgive my hard words and flame me if you must.
Words to live by? Seriously, I'm hardly one to judge. [smilie=l:

Pay special attention to "Nosler 7 STW factory load" read the explanation to the side of the picture, scroll down and see ".223 Rem- 40gr V Max Moly".
Largely irrelevant here. INTERESTING I will say! But we're trying to chase down pressure excesses due to undercharged loads. That factory load doesn't seem to fit the bill.

Now remember, S.E.E. this is just a myth. Totally unreproducible in laboratory tests.
Do I sense sarcasm? I don't recall saying SEE is a myth. Just asking if we can verify it happens with undercharged loads. 1,522 words from John R seems a little excessive to say "Haven't seen it in the lab. Got some good theories about it. Gunpowder can detonate, but don't know if UNDERCHARGES will do so with catastrophic effects."

Why dont you do some research of your own and post your findings for the edification of castbooliteers?
I already did. Negative results. Other "experts and members working on becoming experts" here have as well. Negative results. But the quest continues!

[felix]

It is better to see what creates a SEE condition(s) rather than limiting it to only a charge percentage. ... felix

[stillkickn]

Altitude 19, if I may ask, why do you want the "proof"? As a newbie this thread has been good for my education so I have been glad to read all 102 posts. But then I wondered, what is your goal. Just curious.
TIA,
Kickn

[waksupi]

Try going over to the Accurate Reloading forum and ask there.

[W.R.Buchanan]

to the OP: I got into this one late but here's what is happening and forgive me if someone in one of the 100+ posts has outlined it previously.

If a case is less than half full of a powder like H110/W296 what happens on ignition is the flame from the primer sets off the side of the charge,(known as "Flashover") and burns thru to the other side. This distance is about .200. Since so much of the charge is burning at once pressure does tend to spike much higher than if loaded correctly.

Thus the charge burns much faster than if it is ignited at the rear and burns from one end of the case to the other which is a distance of about .800 , or for this conversation, it takes 4 times longer to completely burn Thus the peak pressure is lower.

The net result of this condition is that the charge reaches peak pressure 4 times faster than if loaded correctly and it also reaches 4 times the pressure.

Whether or not this will blow up the gun is another matter completely.

I get what you are saying as far as wanting lab proof that this condition exists. However reading a book about how firearms propellants work and why would answer all of your questions and more. I would suggest "Propellant Profiles" from Wolfe Publishing.

I also do question things that don't seem right, like shooting cast boolits in Glocks, but on this one I would not question it as I have known about it since 1972. Besides after you read that book I mentioned, you'll realize that H110 doesn't work very well in reduced charges simply because it needs high pressure to burn right. I reserve H110 (which I have 8 lbs or more of) for full power loads.

As far as lighter loadings, that's what they make Unique for. At 7.0 with a 240 gr cast boolit you can get 1,000 loads out of a lb of Unique powder. With H110 you're looking at 300.

Randy

[altitude_19]

If a case is less than half full of a powder like H110/W296 what happens on ignition is the flame from the primer sets off the side of the charge,(known as "Flashover") and burns thru to the other side.
What's the source for this data? It's the most likely theory I've heard, but seems to contradict KNOWN SEE conditions from factory ammo that goodsteel provided (a factory load .223).
I've also heard SEE occurs when the bullet stops momentarily in the bore...It seems we have two mutually exclusive theories here (flashover vs. bore obstruction).

[swheeler]

Other "experts and members working on becoming experts" here have as well

A19 if you really want to prove it why not try by starting with components that have a good chance of giving you success. Take your favorite 06, a jacketed bullet of 150 grs and one of the slower IMR powders 4350,4831 or 7828, which ever you can find ample data for in several manuals. Now prime the cases with as many different brands of standard LR primers as you can(keep them seperated by manufacture), use the lowest starting load published in any manual and reduce loads 1 grain at a time until you get a definate delayed ignition, be sure to seat bullets so have a good jump and do not clean the rifle once you start. It may be helpful to use a rifle with a rough throat, good and "alligatored up" from extended firing and no cool down. Now that you have a load that is giving you a click -bang a high percentage of the time load up 50 with the different std LR primers you have. Make sure the camera is running and a chronograph might come in handy to record extreme spreads and velocity for us noobs. Fire away and have fun! Now if you don't find happiness, DON"T GIVE UP. Load 50 more but 1/2 grain lower loading and try again on a day when the temperature is cooler, let's say 20 degrees cooler, be sure to keep the camera running while loading too, we don't want to have you shooting a overload and thinking you had a SEE!:) Keep trying and you will succeed, I have faith in you! If you can not accomplish this simple task ask for help. I will be glad to share some IMR 4227 data with you that may be of some help, and remember NO FILLERS, you can't cheat to NOT succeed. Will you please make sure the camera is a safe distance from the bench, or protected by some kind of adequate blast shield, it would be a dirty shame to loose the footage, not to mention you may loose your fifteen minutes of fame, that would be sad!

PLEASE NOTE: THIS INFORMATION IS FOR ALTITUDE 19 ONLY, THE REST OF US CAN JUST WAIT FOR THE REPORT WHEN HE IS FINISHED.

[W.R.Buchanan]

A19: Just call Hodgdons. They will explain it to you better than we can.

Randy

[MBTcustom]

Also, I need to tell on myself a little bit. I confess that I was looking at the ballistics laboratory there because it is a modern version and Oehler is not making their lab (even in windows 95) anymore, and its quite a few thousand dollars cheaper. I had converse with Larry Gibson and asked him if he had any experience with that system and could he compare the two? He told me that the secondary pressure spike only shows up on the RSI Pressure Trace II system, and could not be reproduced by the Oehler System. The Oehler is a respected (albeit outdated) system and Larry seemed to take its word over the RSI system, saying "you get what you pay for". While that is true, I do wonder (especially because you cant even pay for the Oehler lab anymore:p) which one to believe. I just thought I should in good conscience, give this information for you to think about because Larry Gibson is a respected voice on this forum and he said that those graphs could not be trusted.
Altitude19, I apologize for my sarcastic tone in earlier posts.
I read what swheeler wrote and although his post was heavily laden with sarcasm, I think he has a good plan for the testing of this theory. (with the exception that you should be behind the blast shield with the camera)
After thinking about it, I am getting more and more curious about this.
I have some serious questions for you, all sarcasm aside:
Do you have a place to shoot where you can do this experiment?
Do you have a buddy that can go with you so that you have witness/help?
Can you get a rifle to sacrifice for experimentation? (I think that a turkish Mauser might be the perfect victim. They can still be had for less than $200)
I just might do this myself, I am almost totally set up to do this with the exception of having the rifle. (I dont want to blow up Winifred)
Hmmmm.
I believe that S.E.E. is a real thing but I also like blowing stuff up. Let me do some more thinking.

[Larry Gibson]

Let me make a point of clarification;

I have hands on dealings dealings with only 1 RSI system. I have been "consulted" with by email and phone on trouble shooting problems with a couple other RSI systems. There are obvious setup differences between the Oehler M43 PBL and the RSI system. The set up for both must be correct for reliable readings to obtained. It is not difficult but must be done correctly.

There are 2 obvious external differences The RSI boasts the pressure sensing gauges are "non-permenant", i.e. they can be attached and removed without damage to the finish of the barrel. The gauges with the Oehler M43 are permanatly attached with a very high strenght super glue after the bluing is removed and the bare metal is chemically cleaned. The RSI uses a plug in attachment to the gauge. The Oehler M43 requires the wire leads be soldered to the gauges to delete/minimize "noise" (spikes in the time pressure curve graph) and inconsistent measurements.

Also I found in all instances the RSI users were not positioning or shielding the instrumentaion from the muzzle blast.

With the one RSI I worked with we permanantly attached the gauge, cut of the plug ins, soldered the wire leads and repositioned the electronics away from and protected from the muzzle blast. The readings were considerably improved but still were not as consistent with those obtained by the Oehler M43. BTW; we attached two gauges to one .308W barrel and compared the readings of the same cartridge (known factory load used as a "reference") out of the same rifle between the RSI system and the Oehler M43. Hopefully the M43 will be available again with updated software. That's all I have to say about that.

Larry Gibson

[swheeler]

Let me make a point of clarification;

I have hands on dealings dealings with only 1 RSI system. I have been "consulted" with by email and phone on trouble shooting problems with a couple other RSI systems. There are obvious setup differences between the Oehler M43 PBL and the RSI system. The set up for both must be correct for reliable readings to obtained. It is not difficult but must be done correctly.

There are 2 obvious external differences The RSI boasts the pressure sensing gauges are "non-permenant", i.e. they can be attached and removed without damage to the finish of the barrel. The gauges with the Oehler M43 are permanatly attached with a very high strenght super glue after the bluing is removed and the bare metal is chemically cleaned. The RSI uses a plug in attachment to the gauge. The Oehler M43 requires the wire leads be soldered to the gauges to delete/minimize "noise" (spikes in the time pressure curve graph) and inconsistent measurements.

Also I found in all instances the RSI users were not positioning or shielding the instrumentaion from the muzzle blast.

With the one RSI I worked with we permanantly attached the gauge, cut of the plug ins, soldered the wire leads and repositioned the electronics away from and protected from the muzzle blast. The readings were considerably improved but still were not as consistent with those obtained by the Oehler M43. BTW; we attached two gauges to one .308W barrel and compared the readings of the same cartridge (known factory load used as a "reference") out of the same rifle between the RSI system and the Oehler M43. Hopefully the M43 will be available again with updated software. That's all I have to say about that.

Larry Gibson

Larry; how much difference was there between the two systems pressure readings?

[robertbank]

Guys I am a rookie in all of this so be gentle. I load 19 gr of 4227 in my Longbranch .303B. My OAL puts the bullet into the rifling as I seat the cartridge in the chamber. I have been doing this for years now. I pull the trigger and the gun goes bang. It has been doing this with this and other rifles I have had for the past 20 years or so.

What is the difference between seating the bullet into the rifling before firing and what you have described as the reason why SEE happens. What am I missing?

Take Care

Bob

[MBTcustom]

I think that it would be about the same as if you used a dowel rod to lodge that boolit 1" into the rifling, closed the bolt on a case with a lighte charge of slow burning powder, and pulled the trigger. Near as I can tell. I know for a fact that the power of the primer alone will produce that scenario exactly (dont ask). I am still trying to decide what exactly we are talking about. There are any number of scenarios that could happen in that millisecond.

[MT Gianni]

Bob, As I understand things the difference between seating in the lands and an SEE is that the powder burn is consistant when the bullet is seated properly forward. You have an accurate working load seated properly.
With a low charge of a slow powder, the burn may swirl instead of moving from back to front. The resulting initial burn swirl causes a bump that sticks the bullet, slowing monentum then milliseconds later the pressure wave of the full burn begins to exert force on the bullet. This pressure wave is an unknown burn rate as the powder is not being burned as designed and there is now a bore blockage. Ka-blewie.

[MT Gianni]

What's the source for this data? It's the most likely theory I've heard, but seems to contradict KNOWN SEE conditions from factory ammo that goodsteel provided (a factory load .223).
I've also heard SEE occurs when the bullet stops momentarily in the bore...It seems we have two mutually exclusive theories here (flashover vs. bore obstruction).

Not exclusive, the flashover burn causes the obstruction milliseconds before the burn wave hits it.

[Larry Gibson]

Larry; how much difference was there between the two systems pressure readings?

As I have no print outs from the RSI test I'll choose not to say. Suffice to say there were some problems not only with the psi difference but the addtional data. Whether the problem was whether from the RSI equipment of the "set up" and attachment of the strain gauges I can not speculate.

The Oehler M43 with that rifle using that lot of "reference" ammuntion in that test rifle has been very consistent for 2+ years. The measured psi (M43) are also quite consistent with what the factory technitions advised me the psi of that lot was when they tested it. The M43 also has yeilded consistent results on many tests conducted with 30 different test barrels of 26 cartridges.

If there are any RSI users I would really like to compare notes/data and perhaps do another side by side comparison?

Larry Gibson

[robertbank]

Bob, As I understand things the difference between seating in the lands and an SEE is that the powder burn is consistant when the bullet is seated properly forward. You have an accurate working load seated properly.
With a low charge of a slow powder, the burn may swirl instead of moving from back to front. The resulting initial burn swirl causes a bump that sticks the bullet, slowing monentum then milliseconds later the pressure wave of the full burn begins to exert force on the bullet. This pressure wave is an unknown burn rate as the powder is not being burned as designed and there is now a bore blockage. Ka-blewie.

Thanks, makes sense. I wasn't overly concerned about the method I was using. I have had one five shot 1.5" group at 100 yards with the old Longbranch with a scope mounted on her and now I strive to do it again. Might be awhile and time is not on my side.:-)

Take Care

Bob

[BeeMan]

Swheeler in post 108 hints at something frequently overlooked when this discussion makes it periodic appearance on these boards. Rarely are these types of problems due to a single variable going out of some clearly defined and measured limit.

Case in point: a project at work a few years back where a product with long proven design and successful application history inexplicably developed critical failures. I led the team through an all hands analysis and resolution. One exercise was to identify points of variability in process (not design). We uncovered 150+ areas where a relatively simple mechanical assembly could deviate from original design intent. We prioritized and focused on the critical to quality, then implemented and validated the results. Obviously design updates to eliminate manufacturing variability were a key to accomplishing this. Howevr original design intent did not change. Since that project completed, there have been zero defects.

When one presumes to exceed limits established for a critical to quality component, they had better KNOW that all other variables are understood and controlled.

I'm not that good at my hobby of internal ballistics, so there are some things I'll just take on faith. There are plenty of reasons why not all powders are listed for all cartridges in the manuals, and its probably not due to keeping page count down.

BeeMan

[Larry Gibson]

Guys I am a rookie in all of this so be gentle. I load 19 gr of 4227 in my Longbranch .303B. My OAL puts the bullet into the rifling as I seat the cartridge in the chamber. I have been doing this for years now. I pull the trigger and the gun goes bang. It has been doing this with this and other rifles I have had for the past 20 years or so.

What is the difference between seating the bullet into the rifling before firing and what you have described as the reason why SEE happens. What am I missing?

Take Care

Bob

You are probably using enough 4227 to negate a probable SEE. Also an SEE with a medium to heavy cast bullet is even rarer. You might get a bit better accuracy and less ES fps with a dacron filler and perhaps a gr or two less of 4227.

Larry Gibson

[Bullwolf]

I hope this is relevant to this topic. I borrowed this information from the AMT forums, back when I was trying to work up some reduced 50AE loads for my AMT Automag V pistol.

http://www.amtguns.info/forum_posts.asp?TID=105&PID=749

I thought that this was a good example of less = more, or higher than intended pressure results when loading too light charges of a slow burning powder. Bluedot in this example.

This was cut and pasted from a post by Stainless Magnum on June 2008 over at the AMT Gun Forums.
<snip>
-----------------------------------------------------------------------------------------------------
The 325 grain NEI with 16 grains of blue dot seems like an underload. If memory serves me correct, 21 grains of Blue Dot is a proper load for a 325 grainer. 16 would be a 25% reduction. 10% reduction would be more in order, at about 19 grains. If it behaved nastily, it could have been high pressure. It comes to mind only because of an experience I had similiar to this. I did a chronograph test series of the .50 AE and accidentally discovered the following:

15.5gr. Blue Dot under 350gr. XTP gave 1020 f/ps
15.1gr. Blue Dot under 350gr. XTP gave 975 f/ps
14.7gr. Blue Dot under 350gr. XTP gave 910 f/ps
14.5gr. Blue Dot under 350gr. XTP gave 1425 f/ps!!!!

The chronograph was checked for consistency, but recoil/blast was confirmational anyways. 5 rounds gave this result consistently. Pulling the remainder, and reloading back up .5 grain dropped the velocity back down. I no longer go below 15.1 grains on this bullet. I wonder if perhaps the same result happened to you. All the loads above, except for the underload, were mild to shoot (relatively speaking). Let me know what you think. I may have it all backwards, but my curiosity got the better of me

Cautions of note. This was a renegade project for me, and post it for academic purposes. The 14 grain charge should not be reduced. I calculated it as a minimum, and have had high pressures before from Blue Dot undercharges. No explosions, but ridiculous recoil, velocity, and other notable signs in the cases.
--------------------------------------------------------------------------------------------------------
<end snip>

I did not witness this personally. I also don't know if this would blow up a gun or not. I do know that I won't be testing it in my older Automag V. I will not be reducing Bluedot (14 grains or less) in a 50AE case after reading this. I thought it was a good example of a lighter charge of a slow burning powder, causing higher than intended pressure.

This post is not intended as a slight on Bluedot. I have no problem using Bluedot where it is applicable, and I really like Bluedot. I use it in many other cartridges. I just decided to stick with safer, more consistent behaving powder selection for my light 50AE loads, such as Unique, 2400, AA#9, and IMR4227. In my situation, pressure levels were not high enough for good results using A2400, or AA#9 with my lighter loads. IMR 4227 turned out to be the best reduced velocity powder choice.

I only wanted a light 50AE load so I would have a safe subsonic plinking load that I could shoot in my old Automag V. A load that would keep me from battering the gun, as well as the slide and frame of a pistol notorious for cracking slides. No safe queens for me!

The best subsonic load that I found for use in my own personal Automag V was a 300 grain Hornady XTP HP, behind 26.5 grains of IMR4227, using Hornady Brass, and a CCI #350 Large Pistol Magnum Primer.

Here are the results of a string of 26.5 grains of IMR4227, that I shot across my chronograph.

FPS
---------
1040
1012
994
975
1016
997
977
985
1010
983
1018
1014
998
976
1023
978
---------
999.75 Feet Per Second average.

- Bullwolf

[Reload3006]

Ok I cannot find my articles from Olin labs as promised. I apologize. From Winchester Data pamphlet second edition June 1975 PG 69 Note.

296 powder is considered to be one of the best powders for use in Magnum revolver cartridges. For such Loads we strongly recommend the use of a Winchester-Western magnum Primer and a very heavy crimp (high bullet pull).

Failure to follow this procedure could result in poor ignition and or / squib loads under extreme circumstances, particularly in loads where less than 90% of the available powder space is being used (low loading density).

Do Not reduce powder charges with 296 powder. These loads must be used exactly as shown. A reduction in powder charge or change in components can cause dangerous pressures.

Ok that was from Olin Winchester. Its good enough for me. Call it what you want to. A Kaboom by any other name is still a Kaboom.

But for those who dont believe I suppose the best course of action for you is to pave your own path and if you live to tell the tale you can say you are smarter than everyone here in addition to Olin among others.

[altitude_19]

Do you have a place to shoot where you can do this experiment?
Do you have a buddy that can go with you so that you have witness/help?
Can you get a rifle to sacrifice for experimentation? (I think that a turkish Mauser might be the perfect victim. They can still be had for less than $200)
I just might do this myself, I am almost totally set up to do this with the exception of having the rifle. (I dont want to blow up Winifred)
Hmmmm.
I believe that S.E.E. is a real thing but I also like blowing stuff up. Let me do some more thinking.
I have a place and the desire, but not the means. I can't afford a sacrificial rifle. THAT and the point has been raised that the pass/fail test of blowing up a gun is less than scientific...I sure don't have the equipment to take pressure readings.
I know Olin Winchester published material advising against this, but it's something I'd really like to UNDERSTAND, not just believe.

[MBTcustom]

Well, I was the one who raised the point that blowing up a rifle is not scientific per say, but It is definitive and in the absence of any affordable testing equipment, (which I honestly believe could be sold for a fraction of the cost) Its about the only thing available to a layman.
A turkish mauser is $200, I just dont see how you can beat that for a test. Right now though, I dont even have $200. If I did, I would be putting some much needed tires on the 'ol Toyota.

[swheeler]

I have a place and the desire, but not the means. I can't afford a sacrificial rifle. THAT and the point has been raised that the pass/fail test of blowing up a gun is less than scientific...I sure don't have the equipment to take pressure readings.
I know Olin Winchester published material advising against this, but it's something I'd really like to UNDERSTAND, not just believe.

I believe every reloading manual I've read has a warning about using loads less than recommended starting loads. Lyman does their own pressure testing by the copper crusher method and they have a warning, and it does not state slow rifle powders just that using less than the recommended starting load can cause dangerous pressures. I don't think they would print this just for grins, then if you search Larry Gibson has posted an article on here about SEE, with the pressure data. Then you have first hand SEE stories by people like BB in 7mm REM Mag, you can't get a double charge of an appropiate powder in that cartridge. Now when I look out my window the earth sure looks flat, do I believe it is, NO, do you believe it is flat?:kidding:

[MBTcustom]

I know how Mythbusters would handle this. They would build up 5 cartridges with different powders at "recommended" reduced loads, strap buster to the rifle and shoot all five. When none of them destroyed the rifle, they would pronounce the myth "busted" then pack a cartridge with dynamite, plug the barrel, and blow that sucker into next week.
Unscientific! Crude! Inconclusive! Sweeeet!!![smilie=l:

[462]

"but it's something I'd really like to UNDERSTAND, not just believe."

Hmmm . . . 126 posts, including many giving detailed explainations of why and how it happens, and you still don't understand? I'll admit to being a shallow thinker, then, because I understand and believe.

[swheeler]

Lyman #47
Suggested Starting Grains
Loads shown in this column are the place to begin load development. Use the exact charge shown. Never go below the starting charge as to do so can sometimes cause dangerous conditions. Lighter charges can sometimes result dangerously high pressure..........................................

Do I believe everthing I read, no not everthing. These are the guys doing the pressure testing and I doubt they would put this in their manual unless they had experienced this while pressure testing ammo. Some people just need to be hit over the head with a 2x4(or maybe a scope or splintered stock) for the lights to come on.

[stillkickn]

Lyman #47
Suggested Starting Grains

Do I believe everthing I read, no not everthing. These are the guys doing the pressure testing and I doubt they would put this in their manual unless they had experienced this while pressure testing ammo. Some people just need to be hit over the head with a 2x4(or maybe a scope or splintered stock) for the lights to come on.

Folks, unless I've missed it, I have not yet seen the post where altitude 19 doesn't believe in rifles blowing up. In post 123 he even says "I'd really like to UNDERSTAND, not just believe."

I am happy to follow the rules and load within published limits but there is nothing wrong with getting the best information you can on a subject. There has been a lot of very good information in this thread by some very smart people. Those people got that way digging the deepest.

[MBTcustom]

I agree with stillkickn. We dont come to this web site to blindly follow limited traces of information. If we did that, then none of us would ever push boolits past 1800FPS, we would not make our own lube like FWFL or 45/45/10 (which by the way is explained in excruciating scientific detail so that we understand why every component is there and why the quantities are exactly just so), I would never have rebarreled a rifle, made a custom wildcat, etc etc etc. Pick your subject. I believe that SEE is real, but why do I believe it? Because someone who cant reproduce the results, (and apparently lost the results when it did happen) says so.
Its not the way we do things here, to take information on blind faith is against castboolits philosophy.
Not slamming anybody, and not advocating that someone mess with dangerous things, and not disbelieving personal experiance of those who have posted, (thanks for that by the way) but I am convinced through reading this thread that nobody understands this phenomenon. We seem to understand it the way we understand the Bermuda triangle.
As a cast booliteer, that bugs me!
The more I read this thread the more it bugs me. Altitude19 got under my skin at first, but now I see what he is so dug in about.
For instance, I would like to know how much pressures raise do to a SEE event. The answer? A lot!
The truth is, that at this point what we are dealing with is blind faith. Probably well founded blind faith, but it is based on a few unsubstantiated words in a few reloading manuals.
The questions being asked are simple enough:
Who tested this?
What did they test and what were their results? What was the highest pressure recorded? What was the most volatile combination?
When were these tests conducted?
Where were these tests conducted?
Why was there a need for a test in the first place? (this is the only question I feel has been adequately answered.)
How many tests were conducted?
How were these tests conducted and with what equipment?
How was the data analyzed?
How do you get 129 hard hitting posts without answering these 6 basic scientific questions? Go back through this thread and see how many of these questions were answered succinctly.
I think the simplest answer is that we don't know!!! We have allowed certain pieces of important information to get lost.
It would be good to know though. There are very few unexplored areas of this sport left, and this is one that was known at one time, but not any more. Sometimes there are so many men standing on each-others shoulders that the one at the bottom gets buried.
Beware folks, this is how information gets lost. Fact turns to belief, belief to legend, legend to myth, and myth turns into superstition.
I'm going to start digging. When I find information I will submit it to the masses. I hope I dont have to recreate these tests myself to find the answer's.
Please everybody, keep your eyes open and if you run across some of this information, please PM it to Altitude19 or myself?
Ill bet its just buried in some filing cabinet waiting to be pulled out and dusted off.
Thanks!:drinks:

[Larry Gibson]

"but I am convinced through reading this thread that nobody understands this phenomenon."

Many of us do understand the phenomonon of S.E.E. All of your questions and doubts are well answered in Bret4207 #41 post with the information provided by C.E. Harris. Also I have post this article from Handloader Magazine titled Mystery Solved.

Handloader- readers have doubtless heard of a term called secondary explosion effect (S.E.E.). It is a theory that attempts to explain the catastrophic failure of some rifles while firing seemingly reasonable handloads or reduced loads using slow-burning powders. Theories have been offered and debated in these pages and elsewhere, but they have been just that, theories, because no one has been able to reproduce effects under laboratory conditions. The purpose here is not to debate S.E.E. but rather to report on a specific incident and the results of tests done to discover the cause of catastrophic failure.

One of the great problems with attempting to theorize on the cause of catastrophic failures is that we must do so after the fact. We have the corpse, usually with some parts missing and must try to figure out what went wrong. Learned theories are offered, sometimes conflicting, and we end up with a bunch of folks shouting in print, 'You're wrong.' "No, you’re wrong." Since the event they're arguing about what without benefit of instrumentation, either one could be right. The events I describe here represent the first instance of an event produced under controlled laboratory conditions and documented on industry standard pressure measuring equipment that provides a plausible explanation offered to explain S.E.E.

The following is simple. It goes all the way back to Shooting 101 where we learned that bore obstructions blow up guns. There are no explosions, no mysterious wave amplifications; it's just a case of several factors, combining in worst case conditions to create a bore obstruction with the bullet.

In early 1989 a major manufacturer began development of a load for the 6.5x55mm Swedish that was to be added to their product line. Development was uneventful and all work was done using the copper crusher pressure measuring system, for there were no standards established for piezo-electric pressure measurement in the 6.5x55mm. The copper crusher method of pressure measurement has been with us for generations, but it is not without its limitations. The results obtained are not true "maximum" pressures, and it provides only a single data point. There is no way that one can deduce what is happening during the period the powder is burning, nor can one see other significant ballistic events.

A quantity of ammunition was loaded using a relatively slow-burning, non-canister propellant with a 140-grain bullet. After load development in ammunition manufacturer’s pressure guns, it is common practice to function test ammunition in a variety of available rifles to ensure satisfactory performance before it is released for sale to the public.

As function testing of the 6.5x55mm ammunition was begun using Swedish Mauser rifles, they noticed some of the same signs of excess pressure every handloader is taught to look for - flattened primers, enlarged primer pockets and heavy bolt lift. All the ammunition fired in the pressure gun had been perfectly acceptable, but SAAMI test barrels and chambers are made to tightly controlled specifications so the first supposition was that some element within the test gun was contributing to high pressures. Then a "spontaneous disassembly" occurred that destroyed the action but left the barrel undamaged. The bore was clear and showed no bulges. It was immediately identified as a high pressures failure and an investigation was begun. The barrel from the wrecked Mauser action was fitted with a collar that allowed it to be mounted in a universal receiver, and an industry standard conformal piezoelectric transducer was installed. Another test was performed using the Oehler Model 82 piezoelectric pressure measuring system equipped with a trace hold oscilloscope.

(Fig !)
round pressure (psi) velocity (fps)
1 48,820 2,601
2 53,849 2,662
3 57,609 2,708
4 57,999 2,720
5 54,093 2,687
6 58,634 2,731
7 62,150 2,754
8 82,120 2,875

Pressure tests are commonly done with a 10-round string and as you can see from the chart, pressures increased very gradually on rounds I through 4. At the fifth shot, pressure dropped and then continued to increase until, at the eighth shot, pressure, went to 82,120 psi; and the technician wisely stopped the test. The raw data was then used to prepare additional graphs (fig. 1) which show that, after ignition, pressures dropped momentarily to near zero on the graph before beginning to rise again.

To interpret this data we have to first understand the ground rules applicable to pressure testing with conformal transducers. The key term here is 'offset" which relates, primarily, to the specific cartridge and the brass used therein and must be determined for each transducer and lot of brass. The offset is the amount of pressure required to obturate the case to the chamber and begin to exert pressure upon the transducer. In this case the offset was 3,800 psi so when we look at the time/pressure curves produced in the test; we must understand that we are not actually seeing pressures below the level of the offset. There is a distinct dip in the curve, however, shortly after the pressure begins to rise when it drops to a level somewhere at or below the offset pressure. All we can say for sure is that, at this point, the pressure is <3,800 psi. Engineers calculated that for the specific bullet being used it would take pressure of at least 5,000 psi just to keep the bullet moving.

As I said, there are a number of variables at work here, but the main culprit is a very long leade or throat erosion. It takes relatively little pressure to eject the bullet from the cartridge case (de-bullet), which produces a significant increase in volume. Unless the rate of gas production is fast enough to keep up with the increase in volume, pressure must drop. The simple equation is PIVI=P2V' where P = pressure and V = volume. It is helpful in considering the phenomena reported here to view the rifle barrel and chamber as a cylinder whose volume is determined by the position of the bullet at any given point in time. If the bullet is moving, the volume is continuously increasing until the bullet exits the barrel.

If P2 is at or below the pressure required to keep the bullet moving it must stop. Then we run into our old friend inertia. Bodies at rest tend to remain at rest, but all the powder burning behind the resting bullet doesn't know about that. It keeps burning and pressure rises. Sometimes we get lucky and the bullet starts to move and relieve some of that pressure, but in a worst case of a rough bore and/or soft bullet it doesn't, and pressure continues to build until something else lets go. Most of the time this will occur around the primer pocket and gas will be released through the flash hole, but we're talking about events that are taking place quickly (milliseconds); and if pressure rises at a rate faster than it is being relieved, a catastrophic failure is inevitable It has been theorized that many 'accidents" represent a combination of effects which combine, in worst case conditions, to produce a catastrophic failure. Robert Greenleaf (Rifle No. 146) presents convincing evidence to show that conditions rarely remain the same, and the condition of the barrel and throat combined with different bullet characteristics can produce markedly different pressure levels for the same load. This is certainly seen in this data where a series of eight shots of the same ammunition delivered pressures ranging, and steadily increasing, from 48,820 psi up to 82,120 psi, at which point the test was stopped. We can, from looking at this test data, presume that all rounds (except perhaps the first) displayed some degree of temporary bore obstruction, but that the bullet was blown out of the barrel. Fortunately universal receivers are capable of containing considerable pressures, and it is certainly possible that the pressure generated by the last shot would have wrecked a standard rifle.

One factor that cannot be accurately measured with this data is the possible contribution of fouling from the bullet itself. It seems reasonable to assume that some accumulated fouling was blown out on the fourth shot, which accounts for the drop in pressure at shot No. 5.

When the engineers were able to examine and expand the time/pressure curves produced during this test, it became obvious that each shot showed a pronounced drop in pressure very early in the ignition/burning cycle and, on the shot where the pressure reached 82,120 psi, it dropped to the baseline before resuming a climb to the stratosphere. It would be easy to think that the fire went out, but a more reasonable explanation is that the burning rate of the powder became even slower. We know that pressure is a major component of the burning rate of any powder, and it depends upon adequate pressure levels being reached and maintained. In fact, what is shown in this case is that the amount of gas being generated was not sufficient to keep the bullet moving. If pressures drop below some optimum level, burning slows down and is often incomplete. Of course there will always be a quantity of unburned powder from any shot, and this observation has led to some of the conclusions regarding S.E.E.

In order for the pressure to rise to catastrophic proportions some other adverse conditions must also be present. These involve the cartridge case, the bullet, chamber and barrel and need to be discussed individually.

Bullet pull: We know that an adequate amount of tension between the case neck and bullet is a prerequisite for uniform combustion. This term, called bullet pull, is independent of the firearm and is routinely measured in the factories. Crimps may or may not be used to increase bullet pull, but most centerfire rifle cartridges depend primarily on tension between the case and bullet. If you've ever committed the sin of firing a cartridge into which you have neglected to dispense powder, you know that the primer alone is perfectly capable of propelling the bullet several inches down the barrel. Pressure generated by a primer alone can be as much as 4,000 psi in a conventional centerfire rifle cartridge; so it is certainly possible, in a normal round, for the primer impulse alone to be sufficient to get the bullet moving before little if any pressure has been generated by the powder charge.

Chamber: In the area of the case neck there must always be some clearance between the case and the chamber wall, but if this area is too large there is little resistance and the bullet can be released with very little pres sure behind it.

Condition of the barrel and throat: The impact of conditions within the chamber and throat are difficult for the handloader to analyze, and a throat that appears normal under cursory inspection may be revealed to be rough and irregular when seen through a bore scope. Greenleaf's report (Rifle No. 146) details how pressure increased as the number of rounds fired through a test barrel grew larger. This can only be attributable to a deterioration of the throat and leade on that particular barrel. In this instance SAAMI standard barrels were used and showed no irregularities, and it was only when the same ammunition was fired in a 'field' barrel with more generous tolerances and wear in these areas that problems were seen.

Bullet hardness and stiffness: The shape and construction of the specific bullet used can be a major factor in the levels of pressure developed by any given load. Bullets undergo some degree of deformation as they enter the bore, and the force required for them to engrave the rifling and obturate to bore dimensions can vary considerably.

Temperature: We know that pressures tend to increase as the barrel heats up, and a round that produces perfectly normal pressures from a cold barrel might show signs of excess pressure when the barrel is hot.

Work presented here answers questions. Some of the findings support theories offered to explain S.E.E. some don't. We haven't, for example, seen any evidence to indicate that there is ever an explosion, and many authorities doubt that there is. Perhaps what we need is a better name. Taken to its most basic component, what we have is that most fundamental cause of catastrophic failures: a bore obstruction. The difference here is that the offender is the bullet itself effect rather than some external source is both predictable and reproducible in the light of this new evidence, but it is highly dependent upon a combination of factors that produce disastrous results. If one or more is absent, everything will probably turn out fine; but when all come together, pressures rise and, sooner or later, sooner or later, something will fail. While it would appear that slow-burning powders contribute significantly, until now we didn't exactly know what to look for. I think it's at least theoretically possible for a bullet to stop in a barrel if the other conditions are bad enough with propellants other than the slower grades.

Have you ever fired a load that you had used often and suddenly gotten signs of excess pressure such as difficult bolt lift or flattened primers, and then fired another that seemed perfectly normal? I think this happens with some frequency, and our normal recourse is to shrug our shoulders and also be a bright red flag waving in keep on shooting; h6wever, this could front of our nose that is telling us that something is wrong. In the light of these findings, it could be telling us that a bullet did a stutter step before it went on out the barrel. The question then becomes what should we do about it. My first suggestion would be a careful investigation of the condition of the bore, especially the throat or leade to see if there is any erosion or roughness followed by thorough cleaning. A chamber cast might be in order to get precise measurements. If the barrel shows obvious signs of wear or throat erosion, the cure is obviously to replace it or set it back and rechamber. If the barrel appears to be within specifications, however, a change of bullet or propellant may be enough to solve the problem. The importance of this information is that it explains, with laboratory documentation, what can happen when the wheels fall off in the worst way. It seems like such a reasonable answer to many of the mysterious ka-booms that good reloaders have had with good handloads, and it is something we all need to keep in the back of our minds in case we encounter something out of the ordinary. While the data here was generated using the 6.5x55 Swedish cartridge, the observations are not specific to that round. They could occur with almost anything.

The facts are there regardless of the "129 hard hitting posts" many from those who simply do not wish to believe the evidence.

Larry Gibson

[MBTcustom]

That's it, I'm done! That should answer it for the most skeptical inquisitor. Whats realy scary is that I recognize some of the details of that account as having happened to me! OMG, I came realy close last summer and didn't even realize it. The rifle was trying to do that very thing. I was shooting a "safely reduced load" in my .358 Malcolm wildcat. In fact Larry Gibson fronted me some boolits to test in it. It was a very hot day and I was shooting a reduced load of H335. I had 15 cartridges that were loaded with 250grain boolits. I didn't have a pressure gauge but I was shooting over a chronograph. I saw the speeds increasing with every shot exactly like the article said! Matter of fact, I still have the piece of paper that I was writing down the speed increases on. I sure am glad I only had 15 shots!
Thanks for that information Larry, I dont know where you found it but that sure is specific. Very interesting too. It backs up a lot of what was said in post #41 plus it gives the date and place. Cant ask for much more than that.

[swheeler]

Larry thanks for posting that for the umteenth time! :)

[Oreo]

Sounds real easy to test then. If all that is in fact what happens.

1. Load a round with live primer & no powder.
2. Fire round in gun. Notice bullet lodged in barrel.
3. Load case with live primer, & light powder charge but no bullet.
4. Chamber this case & fire gun.

Gun should kb reliably in this condition according to the above posts, right?

[stubshaft]

Sounds real easy to test then. If all that is in fact what happens.

1. Load a round with live primer & no powder.
2. Fire round in gun. Notice bullet lodged in barrel.
3. Load case with live primer, & light powder charge but no bullet.
4. Chamber this case & fire gun.

Gun should kb reliably in this condition according to the above posts, right?

I have fired a number of boolits with no powder and have never had one leave the case much less get lodges in the barrel. The only instances which I have had bullets lodge in the barrel were where the powder was contaminated with lube or oil.

The scenario you posted is virtually identical to breech loading a rifle.

[Reload3006]

What is trying to be explained is detonation. not the same thing as Ignition. When a cartridge is loaded with a spicific amout of powder we have a "CONTROLLED BURN" when we have an undercharged case some times we have a "CONTROLLED BURN" other times we have Detonation. I guess the best example of Detonation in a controlled manner is your automobile gasoline is mixed and "ATOMIZED" at the proper amount by Carburation or injection and then ignited. The result is a "CONTROLLED DETONATION" when this accidentally happens in a fire arm its an unexpected and "UNCONTROLLED DETONATION" some times your gun can with stand the pressure and you walk away fine. Other times it cannot and you dont exactly walk away. an automotive example of uncontrolled detonation is spark knock. It happens in cars when there are glowing embers of carbon in the cylinders and fuel vapor keeps being fed to the cylinder and detonated in an uncontrolled manner thus blowing a hole in your piston.

how this example relates to an undercharged and unpredictable occurrence is the amount of air and dust that has "atomized the Powder" in the case. when cases are filled with an appropriate amount of powder it makes atomization impossible. and the result is a "Controlled Burn" again.

[felix]

Yes, it is easier to control the rate of burn (heat generated) in a car engine with the EGR attached. Especially if the engine has computerized controls. ... felix

[robertbank]

I have fired a number of boolits with no powder and have never had one leave the case much less get lodges in the barrel. The only instances which I have had bullets lodge in the barrel were where the powder was contaminated with lube or oil.

The scenario you posted is virtually identical to breech loading a rifle.

This certainly hasn't been my experience. As a Safety Officer running shooters at IDPA matches I have witnessed several squib loads where only the primer was present in the cartridge. In every case the bullet was lodged in the barrel in pistols or in the forcing cone with revolvers. I have also have had direct experience with a Ruger GP-100 where one of my cartridges has only a primer in it. The bullet was lodged in the forcing cone.

Take Care

Bob

[M4bushy]

This certainly hasn't been my experience. As a Safety Officer running shooters at IDPA matches I have witnessed several squib loads where only the primer was present in the cartridge. In every case the bullet was lodged in the barrel in pistols or in the forcing cone with revolvers. I have also have had direct experience with a Ruger GP-100 where one of my cartridges has only a primer in it. The bullet was lodged in the forcing cone.

Take Care

Bob

I'd feel lucky if the bullet got stuck in the forcing cone and inhibiting the cylinder from rotating. I've had a squib with just a primer go far enough into the barrel to allow the cylinder to index. I'm glad I had the gun in my hands and not my sons. He might have touched off the next round......scary!

[robertbank]

I'd feel lucky if the bullet got stuck in the forcing cone and inhibiting the cylinder from rotating. I've had a squib with just a primer go far enough into the barrel to allow the cylinder to index. I'm glad I had the gun in my hands and not my sons. He might have touched off the next round......scary!

Exactly what happened to me at a match. The bullet base just cleared the cylinder. It would have got real exciting had I pulled the trigger again. When I teach our Safety Officer courses I spend some time going over what a squib will do and to pay attention to the shooter and what is happening as he fires his gun. We have a STOP command in IDPA for a reason.

Take Care

Bob

[MBTcustom]

I fired a squib in a long-slide 1911 once. The boolit lodged pretty much in the middle of the barrel, I unscrewed the antenna off my truck and pounded it out with that. Loaded up and rocked on.
In 15 years of reloading I have made two mistakes, that's one, but I also put a double charge of unique in a 30-06 shooting a 165grain RN boolit. It stamped the markings flat on the back of the case and I had to use a rubber hammer to beat the bolt open. Definitely a double charge and not S.E.E. In both instances, I knew there was something not right about that batch of ammo. After the rifle mistake, I dont mess around! If I have any doubts about the quality of the ammo I have made, I pull every blessed one of those boolits and start over. I have only had to do that once. I decided to be more careful and to adopt reloading practices that are more absolute in the way they are conducted. Also the wife knows to hold all phone calls and not to disturb me when I am charging my brass.

[Larry Gibson]

I've had 2 instance of squib loads with cast bullets in revolvers being forced into the barrel by the primer alone. The cylinders could both be turned. I caught myself with a 44 Magnum load and a friend with a 357 magnum load. Had we fired the next shot..............

I've also had several rifle bullets get driven out of the case into the throat/leade by the primer alone, especially with long throated chambers. I've also had some where the pullet stayed in the case neck and was extracted. Subsequently I've refined my loading habits to where "no powder" doesn't happen any more. I've also had a couple factory rounds with no powder in them.

Just because it hasn't happened (yet) to some doesn't mean it won't.

Larry Gibson

[Reload3006]

I had it happen to me just last weekend. in a GP 100 primer pushed a Jacketed bullet 1" up my bore came right out with a piece of drill rod. but it happened. SO lesson for everyone if something doesn't feel right sound right act the way your pretty sure it should STOP AND CHECK THINGS OUT>

[robertbank]

I had it happen to me just last weekend. in a GP 100 primer pushed a Jacketed bullet 1" up my bore came right out with a piece of drill rod. but it happened. SO lesson for everyone if something doesn't feel right sound right act the way your pretty sure it should STOP AND CHECK THINGS OUT>

Perfect.

Take Care

Bob

[Oreo]

I have fired a number of boolits with no powder and have never had one leave the case much less get lodges in the barrel. The only instances which I have had bullets lodge in the barrel were where the powder was contaminated with lube or oil.

The scenario you posted is virtually identical to breech loading a rifle.

Not exactly like breech loading. When breech loading there still isn't supposed to be a significant gap between powder & bullet. In the scenario I'm talking about, & maybe during SEE, the bullet is far enough down the barrel that by the time the powder has burned enough to start the bullet moving (which would be longer then in a properly loaded round due to increased combustion chamber volume) the powder might be burning (& pressure rising) much faster then normal.

[M4bushy]

I had it happen to me just last weekend. in a GP 100 primer pushed a Jacketed bullet 1" up my bore came right out with a piece of drill rod. but it happened. SO lesson for everyone if something doesn't feel right sound right act the way your pretty sure it should STOP AND CHECK THINGS OUT>

While at the range with my 13 year old son, we have a rule, if a hand gun malfunctions while he is firing it, it goes on the bench pointed down range and he notifies me of the issue. We at all times have a squib rod in our range bag so I make the weapon safe, remove the mag/open the cylinder and run the rod down the barrel. I don't care if im sure the round went off, any malfunction we assure there isn't a barrel obstruction with the squib rod.


Ron

[altitude_19]

Well, I learned even more than I was after with this one.
Larry, do you remember who wrote that article? It is EXACTLY what I was after and I'd like to hang on to it for reference when this comes up later (you know it will). Sorry it took me a while to get back to the thread I started. Family emergencies and what-not kept me busy. Thanks for all the input!

[waksupi]

Go find the 1968 editions of Handloader magazine, there are sources for several NATO studies done on SEE.

[Larry Gibson]

Well, I learned even more than I was after with this one.
Larry, do you remember who wrote that article? It is EXACTLY what I was after and I'd like to hang on to it for reference when this comes up later (you know it will). Sorry it took me a while to get back to the thread I started. Family emergencies and what-not kept me busy. Thanks for all the input!

I'd have to dig through my own archives or research but I don't think I have the author. It was Handloader 187, June-July 1997 issue if you in a research mood.

Larry Gibson

[BBarrett]

I have in my shop a custom SSK Contender barrel and Contender frame in .250 Sav. that the reloader under charged the cases. He said he wanted to shoot as accurately as he could with it and thought he could with less powder. I showed him in the books what would happen. The next weekend he showed me what did happen. He ripped the firearm all to pieces. I am sure glad I wasn't there to see it first hand. I do have parts that was left and showed several people what happens. By the way, the fellow died from cancer a few years later, but before he died, gave all that to me.

[GT27]

My opinion is like the other old timers here,stay with whats in the black and white,deviating is bad Ju Ju!!:shock:

[altitude_19]

And now I know not only "what" but "why" as well! :grin:

[MBTcustom]

I too, am going to use this page and the information in it as a reference. In fact I already have! Quite a lot to think about. I'm still trying to make sense of the gradual pressure rise before the big event. I wonder if that is the exception or the rule? I will definitely be watching for it in the future. I just wonder if any other factors could produce a gradual rise in pressure that way, given that the same powder charge and boolit combo is used. I am interested because that is something that you can see on the chronograph a ways before you get a flattened primer or a stiff bolt. I just want to know what I am seeing when I am seeing it.
Thanks again for all the patience and informative posts by all you great fellas.

[o6Patient]

purposely under loading to see if we get a pressure spike? Is that the question?
Sure; I'll use your gun..a long string, and a large tree to hide behind.

[Camba]

In my uneducated opinion, a primer alone going off before the powder begins to burn (in terms of micro/milli seconds) can push the bullet into the landing grooves and as the powder fully ignites it would act as a pipe bomb. And again, that could be hard to prove from load to load. That could result from a low powder load as well as from a full powder load. But it is just my opinion and I don't have any way to prove it other than that.
Camba

[38superdave]

Trying to read this thread through is challenging. I read a few posts then stop to throw something. Bet my cat won't be out and about for next few days after bring spun a 180 after taking an aft hit from a high velocity Justin Roper boot. Didn't mean too, cat just didn't file IFR flight plan before take off, that's all.

Secondary ignition is explained in Vihtavouri manual as "phenomenon." Meaning, it's theory. I'm not a rocket scientist or ballistic expert but have enough sand in my boots to regard secondary ignition as real phenomenon.

No, no worries of secondary ignition in pistol loads. I've tested the theory in pistol all the way down to half grain charges. Slower burning powders have a weird feel in hand after ignition, best description I can muster is wrapping a hand around an inflating balloon. I believe I felt pressure build and release as bullet exited bore.

I spent the better part of two summers working reduced power/reduced recoil 9mm and .45acp loads. I don't need a million dollar lab report to tell me what I already know.

Where we see evidence of secondary ignition/catastrophic case failure is within the new .30 caliber sub-sonic calibers. Scenario is fast burning rifle powder filling a small case portion and long VLD bullet.

It's absurd when posters chime in with the notion of a double charge. For those new to this, verify everything you read. Lots of opinions in reloading forums. Some good, some not so much.

dc.