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I read that article, too, but Greenleaf wrote the one I was thinking of, as it was pertaining in particular to .243s in Savage 110 rifles.
You can roll a turd in peanuts, dip it in chocolate, and it still ain't no damn Baby Ruth.
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Do you remember the year?
Slim
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It might be as far back as the mid-80s, it was quite a while ago. Like I said, I gave the article to a cousin who needed some info from it.
I used to save all the back issues, but finally cleaned house.
Oh, and it might have been "Rifle" magazine, it was a long time ago, but it was definitely a Wolfe pub.
Last edited by ratsmacker; 05/03/08. Reason: added a little info
You can roll a turd in peanuts, dip it in chocolate, and it still ain't no damn Baby Ruth.
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I found Charles Petty's article that was mentioned. Was on a South Africa website.
Have not had success with Greenleaf but still looking. Could someone give a key word from that Greenleaf article title. Tried .243 as key word with name in combos, didn't work.
As a side note, have seen some brass flow graphs with the .243 Win. The high end loads with that cartridge, and the graphs are spooky, and from some of the brass flow, would not cause much of a spike to blow head severely, guesstimating 5000 psi spike (if detonation happened?, question mark means I just don't know) over max, IF brass flow is maxed at that point. The graphs I saw, were researching anomalys with .243 throat erosion and some blow-ups of safe ammo. Think maybe what Petty is writing about could pertain to some of what perhaps was mentioned by the Greenleaf article.
Do we want to Petty article up here? The link is public domain, not Wolfe.
It is spooky, if you read and understand the possibilities.
Last edited by remseven; 05/03/08.
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Nighthawk has referenced P. T. Kekkonen, who has now passed on, a couple of times. P.T. did give a little more detail on what happened than what has been reported so far. 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). Some of the details of the incidents are: 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. The warning is the same as what Ken H. has said in regards to using loads of at least 90%. I have spent a few years tracking the incident down, from P.T.'s reference to P.S. That story about two broken .243 Win. test-barrels and purposeful courting of S.E.E. in Germany is told in the book "Handbuch f�r den Wiederlader" by K.D.MEYER, who was then a director of German DEVA Institute. One of the Swiss members of the S&W forum has a copy of the referenced book and provided this translation from German. For getting a starting-load, orient yourself on rounds with known load-data. Look for rounds with similar case volume and similar bullet diameter and reduce the max.-load of this rounds 25% (better 30%) Don't do this with very progressive powders like f. e. Norma 205, because "underloads", like described anywhere else in this book with this kind of powders can cause S.E.E.
This effect is still a problem for the ballisticans. In the proofhouse of the city Ulm, happened this effect two times in a very short time period. The pressure-measure was dimensioned very big so this part could be used further after the S.E.E. But most of the other parts and the test barrels were destroyed. If fired in a hunting rifle, this load would destroy the rifle in numerous parts. My information came from one of the 18 parts from http://guns.connect.fi/gow/QA.html
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After rooting thru the back issues of Wolfe, I don't find anything that rings a bell on the Greenleaf article, but I distinctly recall it being in an older issue, before they went to color pictures, so it was quite awhile back. I don't know if Greenleaf is still around, he'd retired already from Savage when he wrote that article, but I've seen an article of his in TVHM a few years back, regarding something else altogether.
You can roll a turd in peanuts, dip it in chocolate, and it still ain't no damn Baby Ruth.
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Paul5388...
Informative post. Thanks. Pretty much supports the theory put forward by Ken Howell earlier.
Be not weary in well doing.
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I think P.T. was describing something akin to a miniature fuel/air bomb of a similar variety to what was used in the OK City bombing. There was a dispersant/atomizer and a subsequent igniter. There was also a similar methodology used in Viet Nam.
In relation to the S&W forum issue, it seems to be predominantly a rifle phenomenon, involving slow burning powders with not too greatly reduced loads.
In handguns, it seems more likely that double or even triple charges and/or multiple projectiles and/or bore obstructions account for most Ka-Booms. Other factors can be involved, so the list doesn't have all the possibilities, but there were sufficient "and/or" to get the point across.
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always use ninety to a hundred percent of a case-filling charge of your optimum powder How is "optimum" defined in this sense? Is this basically saying use any powder which lets you fill the case without raising pressures higher than acceptable? Does this work for even big black powder cases, which must keep pressures down in the 20's? I would have to say that filling "big black powder cases" with black powder would be a safe bet. This has been a CRAZY year for all sortsa' off the wall "B.P. Substitute / Equivalent load data. Great thread, all,....really enjoyed this read. GTC
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-- “Sometimes I wonder whether the world is being run by smart people who are putting us on or by imbeciles who really mean it.”- Mark Twain
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I would have to say that filling "big black powder cases" with black powder would be a safe bet. Certainly, but as you point out, people do try all sorts of equivalents. I've wondered if any of those involving smokeless powders are safe. I can see where a hang-fire might generate some gases which later go off, these gases forming something of a super-primer. This would light up the main charge far faster than a regular primer, and the result would be similar to having used too fast a powder, ie. the entire charge burns off before the bullet is far enough down the bore. However, I'm not sure I see why a light bullet is required in the recipe. Does this mean the light bullet jumps down the bore a bit more, giving a larger (and cooler) combustion chamber, allowing more gases to cook off? If so, then a heavy bullet should have a similar effect if the charge is reduced further still. always use ninety to a hundred percent of a case-filling charge Is Hodgdon playing some odds in advocating greatly reduced charges of H4895? How about the BP folks shooting light charges of 4227 and 4198 in the medium length (eg. 38-55 and 45-70) cases? Or is it only the heavily deterred powders which create problems?
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One theory I have heard is that when using slow or hard-to-ignite powders, the primer spark itself can propel the bullet forward lodging it in the rifling before the powder actually ignites, which makes the lodged bullet act like a bore obstruction. It would seem a lighter bullet would be more prone to this. It would also seem that low bullet pull would contribute as well. This is why I carefully brush-out any dry lube from case necks before seating new bullets. As a rule, I also do not use light-for-caliber bullets or light charges of slow powders.
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There may well be something to that, BR. And the rougher the throat, the worse the "obstruction" might be. There IS a correlation of these events to rifles with worn or dirty throats, so maybe...
The only quibble I have with your post is the word "spark" because the primer does a whale of a lot more. It's quite the small-scale explosion, in fact. The primer alone can generate over 3,000 psi and temps of over a thousand degrees.
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Okay, I stand corrected. You must be retired or something.  -
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Harrumph!!!
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"The Genie's Bad When He's Mad"
Always liked the title to that Chapter . . .
. . . and I plagiarize Dr. Howell.
It's doesn't cover SSE, but covers internal ballistics (IB) as much as I care to know about it at present.
Ken, I thought you were coming out with a new one on this topic? Did you? If so, where is it available.
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A single bullet cannot act as a bore obstruction in the usual sense. Read Hatcher.
Alternate theory, and I emphasize THEORY. I don't know.
Assume that the idea that incomplete ignition produces enough heat to decompose nitrocellulose into a mix of explosive gas but not enough temperature to ignite the gas (Kikkonen again, more or less) is correct. Pressure rises as slow decomposition continues and eventually the compression raises the temperature above the point of ignition (diesel effect). Ignition propagates through the gas almost instantly and BOOM!
Now allow the bullet to move forward. The volume of gas increases but there's more space for the gas to occupy. Less compression, less heat, cooler gas temperature. Perhaps the gas never gets hot enough to ignite and the bullet pops out of the barrel.
Ok, now the bullet encounters some resistance to its movement. Could be rifling, rough throat, additional friction from being copper jacketed or whatever. The bullet slows appreciably, space for the gas to expand doesn't increase as quickly, pressure, compression, and temperature rise. Possibly to the ignition point of the gas.
As far as bullet weight, remember that in the .243 WCF fiasco the powder was SLOW FOR BULLET WEIGHT. Heavy bullets have greater inertia and are slower to move forward, allowing less room for gas expansion. Pressure and temperatures rise more quickly and the nitrocellulose is quickly and completely decomposed.
Let me emphasize this is all pretty much guesswork, but seems to fit (so far).
The hard part in thinking about this is that it all happens very fast, much faster than things in our common experience. Even the slowest event is over in less than a tenth of a second. And that is much slower than the normal course of events, where the round fires properly.
The key elements in human thinking are not numbers but labels of fuzzy sets. -- L. Zadeh
Which explains a lot.
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I've seen a number of pressure traces with secondary peaks along the bullet's travel between case and muzzle, apparently caused by rough or constricted bores. None of these secondary peaks was nearly as high as the maximum peak that kick-started the bullet from its stock-still position in the tight grip of the case neck. The bullet was, of course, already moving pretty fast when it encountered the rough spot or constriction along the way.
"Good enough" isn't.
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It would be fun to design experiments to see just what's going on if someone would cough up a couple hundred grand to equip a lab. Don't think it'll happen since SEE doesn't come into play with reasonable loads. As I read it Kikkonen got into it because Europeans wanted subsonic loads for .308 WCF and the like to use with their silencers, and curiosity over European WWII gallery loads. I experimented with very light loads (with unjacketed bullets and the fastest powder I could get) out of curiosity. But it was pretty much pointless with .22 rimfire standard, subsonic and CB caps available.
The key elements in human thinking are not numbers but labels of fuzzy sets. -- L. Zadeh
Which explains a lot.
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I've been out of town for a few days and didn't have a wireless connection.  I think you'll find the use of "guard" loads (reduced power practice loads) were actually in existence in the US also. Most of these "guard" loads were for .30-06 and other rounds, that existed around the turn of the 20th century, very much prior to the introduction of the .308 WCF. I actually use quite a few subsonic loads, i.e. 12.0 gr of Green Dot in .45-70, that are much more useful than a .22 rimfire of any sort. 
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