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one of us |
A long time friend of mine accidently dropped a underloaded charge of a slow burning powder into a 270win short mag. Sierra told him the load had to be below the book minimum for this to occure. first 2 shots went inside a 1/2". The 3rd & the one that wrecked the gun hit 1" from the other two. The barrel landed about 15 feet down range. The scope parts allover the damn place. All he lost was the index finger on his left hand. He was lucky failure Doug Humbarger NRA Life member Tonkin Gulf Yacht Club 72'73. Yankee Station Try to look unimportant. Your enemy might be low on ammo. | ||
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One of Us |
doug you need a logon to see the pic. | |||
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I know my photobucket acct is acting up so i tried this other crap & it no better. I'm working on it. Active X shit is the problem. There! always more than one way to skin a danm cat! you can see the photos now. There are 3 photos. Doug Humbarger NRA Life member Tonkin Gulf Yacht Club 72'73. Yankee Station Try to look unimportant. Your enemy might be low on ammo. | |||
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one of us |
Yow! That is scary. Your friend is lucky he is still on this side of the grass! Have gun- Will travel The value of a trophy is computed directly in terms of personal investment in its acquisition. Robert Ruark | |||
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One of Us |
I am afraid of those fat cartridges! Captain Finlander | |||
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one of us |
Based on those photos, it looks like Remington needs to make a large ring 700 to handle those short mags. There can't be more than an 1/8 th of steel around the chamber. | |||
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One of Us |
WOW! So the load was below book minimum correct? Those squib loads often are more dangerous than overloads. Glad noone was hurt. Curtis | |||
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one of us |
I always throw the charge from the measure into a clear plastic prescription bottle, dump that onto the digital scale tray, check the weight & trickle if needed, then dump the charge directly from the tray into the case filler funnel. I then seat a bullet before throwing the next charge. Sounds like this guy just threw a charge directlyy to the case W/no visual confimation. That scares me! It's not the fault of gun design. It's a reloading mistake. GOOGLE HOTLINK FIX FOR BLOCKED PHOTOBUCKET IMAGES https://chrome.google.com/webs...inkfix=1516144253810 | |||
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one of us |
truly remarkable. hence, this is why I take a flashlight after powder charging to assess uniformity visually, and also why I weigh each charge to this day. Ted Kennedy's car has killed more people than my guns | |||
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One of Us |
Amen to that! I must admit that I have no clue how an undercharge can do that....not saying it's not so.....I just don't understand it at all. The pressure had to be immense.....seems the barrel is split down the middle.....I won't even hazard a guess how much pressure that takes! /////////////////////////////////////////////////////////////////////////// "Socialism is a philosophy of failure, the creed of ignorance, and the gospel of envy, its inherent virtue is the equal sharing of misery." Winston Churchill | |||
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one of us |
My friend was shooting from the bench with his left hand resting palm down pretty much under the floorplate. When the follower came flying down out the bottom it cut his finger off. Doug Humbarger NRA Life member Tonkin Gulf Yacht Club 72'73. Yankee Station Try to look unimportant. Your enemy might be low on ammo. | |||
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One of Us |
I have heard many times an undercharge can cause a detonation vs a controlled explosion. Seems to be true! If you think every possible niche has been filled already, thank a wildcatter! | |||
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one of us |
I think the theory is that the primer flashes over top of the powder that is lying in the bottom part of the case. As I understand it, that ignites the powder across a broad area & the pressure wave travels upward. GOOGLE HOTLINK FIX FOR BLOCKED PHOTOBUCKET IMAGES https://chrome.google.com/webs...inkfix=1516144253810 | |||
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One of Us |
Now that is UGLY roger Old age is a high price to pay for maturity!!! Some never pay and some pay and never reap the reward. Wisdom comes with age! Sometimes age comes alone.. | |||
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One of Us |
Your friend is truely lucky to be alive. I can't imagine the pressure required to do that kind of damage. Thanks for letting us all know what not to do. I weigh and trickle big game charges. Then I visually inspect for the same levels in the case with a flashlight. I dump charges for the 223 or pistol charges directly. I check every thenth cartridge for weight and visually inspect with a light after charging. DW | |||
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One of Us |
This is the first picture & example I have seen of it happening with a big game rifle & ammo. I have seen heaps of pictures of pistols with this phenomenon & of double charges. I always weigh every charge & then visually check the tray before seating projectiles in. "When the wind stops....start rowing. When the wind starts, get the sail up quick." | |||
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One of Us |
Not too bad I suppose, at least the bolt looks usable again and that much maligned extractor is still in place by the looks of it. Your friend was extremely lucky to survive with his face intact as it appears the bolt did hang in there by the skin of the bottom lug? All credit to that. | |||
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One of Us |
Wot??
That would hurt me... | |||
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one of us |
Detonation has been known for years at this point .Initially denied by people it was then duplicated in the laboratory.We now see notes like "do not reduce powder charge" Reduced loads with slower powders is a gamble I won't take !! | |||
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one of us |
Here is an explaination about it by Dr. Oehler. And here is another disaster caused by the same thing and this was a seafire "recommended"(aka Guessed At) Blue Dot Load. | |||
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mete to you have a source for the laboratory relsults. | |||
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Hot core A double charge of blue dot is not a reduced load. | |||
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BTW the bullets he was using were 130 accubonds & AA Mag Pro powder. Also that's a Hart barrel Doug Humbarger NRA Life member Tonkin Gulf Yacht Club 72'73. Yankee Station Try to look unimportant. Your enemy might be low on ammo. | |||
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One of Us |
X2 Reduced loads with slower powders is a gamble with odds stacked in favor of the House !. A few things come to mind ; How much of a reduction was that load ?. How far off the Lands were those 130 accubonds ? ,an the testament too the stocks strength are a couple . I'm not going into any details I'll only venture an educated assumption . Slow powder is difficult too ignite Hence Mag primers , a shallow case load could of allowed flash over. Simply put primer could have detonated and jumped projectile into the lands with insufficient force to clear , allowing a plugged bore scenario then with in Milliseconds burn ignited full charge and BOOM . Years back while working in that industry , A safety meeting and film were shown too crew essential at Hercules and the above mentioned setup was duplicated by Winchester in a Labs test barrel !. Doug ; Your friend is so fortunate as that looked to be a shrapnel face pin cushion possibility !. | |||
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One of Us |
underloaded charge of a slow burning powder into a 270win short mag. Sierra told him the load had to be below the book minimum for this to occure. first 2 shots went inside a 1/2". All the classic symptoms of an SEE. Not a case of detonation but simply a bore obstruction. All laboritory proven and posted in a Handloader article many years ago. To bad about the shooters injury. I guess that pretty much destroys the myth that Remington 700s don't "blow up". Larry Gibson | |||
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one of us |
EXACTLY!!! It's been reported for years tho as I understand it the last I heard, the labs couldn't reproduce it. I load only a few cartridges at a time and weigh each powder charge. Also, I NEVER go below the minimum charge in the books. I load for 270 Win., 270 WSM, .338 and, occaisionally, .257 Imp. Good thing your buddy is ok. Bear in Fairbanks Unless you're the lead dog, the scenery never changes. I never thought that I'd live to see a President worse than Jimmy Carter. Well, I have. Gun control means using two hands. | |||
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one of us |
You are correct. But if you follow that thread, you will notice some folks realize it did not have to be a Double Charge for the Ka-Boom to happen. It goes along with Dr. Oehler's example quite well. | |||
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One of Us |
/////////////////////////////////////////////////////////////////////////// "Socialism is a philosophy of failure, the creed of ignorance, and the gospel of envy, its inherent virtue is the equal sharing of misery." Winston Churchill | |||
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one of us |
Vapo, et al: I remember hearing about this phenomonon as a kid in the '60's. As I recall, labs couldn't reproduce it but it was still considered possible. I'll bow to Mete's comment regarding the lab's finally succeeding in duplicating it. I just haven't heard of it over the years. B.I.F. Unless you're the lead dog, the scenery never changes. I never thought that I'd live to see a President worse than Jimmy Carter. Well, I have. Gun control means using two hands. | |||
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One of Us |
Back in the 70's and early 80's there were numerous storys about 38 spec. blowing up with 2.7 grains of bullseye, They claimed detonation. The powder manufacturers couldn't duplicate that either. | |||
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One of Us |
2 1/2 grains of bullseye is among the most common target load ever used in a .38 Special....one would think if it's a hazardous load that it would be well known..... still /////////////////////////////////////////////////////////////////////////// "Socialism is a philosophy of failure, the creed of ignorance, and the gospel of envy, its inherent virtue is the equal sharing of misery." Winston Churchill | |||
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One of Us |
The more I read the more the barrel obstruction thought makes sense! /////////////////////////////////////////////////////////////////////////// "Socialism is a philosophy of failure, the creed of ignorance, and the gospel of envy, its inherent virtue is the equal sharing of misery." Winston Churchill | |||
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<Mike McGuire> |
There is a problem that can occur especially with ball powder such as 748, 760 and the old 780 and sometime with stick powders that are too fast for the calibre and especially with large cases. It is my belief that the following is where the problem has come from. 748 in something like the 375, 760 in 7mm Rem and 300 Win and 780 in 7mm Rem with heavy bullets. What can (and often does) occur is a hangfire that is far too small to notice. However, it causes low pressure signs and the reloader continues to work up his load. But the minature hangfires causing low pressure signs allow the reloader to go above what would be a maximum load for that powder/bullet. Then as the load is increased and the case gets more full of powder the ignition is correct and BINGO Although I have not seen it happen a simlar situation could occur with something like 4350 and heavy bullets in the 264 or 7 mm Rem. But in this case or the ball powder's situation the problem is coming from an overload which has happened because of false pressure indicators caused by minature hangfires. But at this point I still can't see how a reduced load of slow powder can cause a problem. Primer flame "flash over" can't be the answer because ideal ignigtion is when every granule ignites at the same time. Also, flame flash over would apply even more to reduced loads with fast powders. | ||
one of us |
Reread my post. The first two shots went under 1/2" The third shot is the one one that blew up AND the bullet hit 1" from the two other shots fired. No bore obstruction. None. Doug Humbarger NRA Life member Tonkin Gulf Yacht Club 72'73. Yankee Station Try to look unimportant. Your enemy might be low on ammo. | |||
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one of us |
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One of Us |
Is there any legitamate documentation that one can go to? roger Old age is a high price to pay for maturity!!! Some never pay and some pay and never reap the reward. Wisdom comes with age! Sometimes age comes alone.. | |||
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<Mike McGuire> |
Don't think so. But consider the original post
The first two shots are in 1/2" and the "blow up" shot is an inch away and that is supposedly a reduced load of slow powder. Thus we have a 3 shot group of a bit of over an inch and that includes one very reduced load. Something is not right. My own theory is the "reduced load of slow powder" problems are in reality caused by someone using a reduced load of fast powder, then returning the powder measure (or scales) to the full or normal load BUT not changing the powder Thus the overloads are in fact a result of using a fast powder at the weight of the normal load. Many of you will be familiar with stick powders that have a small hole through the centre of each granule. That is to control the burn rate on each individual granule of powder. So again, ideal ignition is when all the granules ignite at the same time. It is a completely different situation to "detonation" with a fuel/air mix in the engine cylinder. The case full of powder is like 100s of little "cyclinders" Solid fuel boosters such as on the shuttle also rely on the whole grain being ignited and the shape controls the burn rate. The powder in the case is not meant to ignite at the bottom and then burn its way up in a manner similar to a firecracker sky rocket launched from a Coke bottle | ||
one of us |
P.O. Ackley discussed this phenomenon in his 2 books. | |||
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one of us |
I'm inclined to accept the "flash over" theory. A reduced load of hard-to-ignite powder lies spread out along the side of the case. Then the primer flash passes over the top of the powder rather than through it. The pressure from the primer detonation pushes the bullet into the barrel to some point; creating an obstruction. There is a delay in the ignition of the powder and it begins to burn, creating an overpressure event. What concerns me is the apparent, appalling lack of steel around the chamber in those photos. The receiver ring is all that appears to hold things together. My personal belief is the barrel breech alone should be strong enough to contain the pressure(normal pressure); without the help of the receiver ring. In this case, no action may have withstood it, but a different design would give it a fighting chance. The M700 action is plenty strong, but when you bore out the chamber paper thin, it is an accident waiting to happen IMHO. De Haas in Bolt Action Rifles described the gas-handling of the M700 action thusly: "In the event of a cartridge head failure,it is unlikely any powder gasses could escape from between the bolt and the barrel, ...." However, he later contradicts himself by describing two instances where shooters were hit in the face with gas and brass from case head failures: " ...a lot of powder gases escaped through the rear of the action; spewing his face with gas and brass." "...he told me he was mighty fortunate he'd been wearing shooting glasses." No, it ain't perfect, but it is a well proven action. It just seems like it is being "hot-rodded" with these super-fat magnums and over-stressing the design. | |||
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