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Thread: Let's Blow Up Some Rifles, Boys...

  1. #21
    Boolit Master Texas by God's Avatar
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    Optimal powder burn rate is determined by bullet diameter/weight AND case capacity. Quit having coffee with that guy

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  2. #22
    Boolit Master

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    I have a 45-70 trapdoor that blew up from not having enough powder. Cartridge was loaded with a 240 grain bullet and 40 grains of RX7. Lots of air space, gun was pointed down to load and then raised up to level. Breach block staid in action but top of action was gone and the barrel was pealed back like a banana. About 4" of the stock was gone. Luckily no one was hurt.

  3. #23
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    John

    That is the 3rd case of S.E.E. in a 45-70 that I am aware of. The other 2 were both Contenders using 2400 powder and 300 gr bullets. Same scenario; light bullet, lots of air space, muzzle raised to fire leaving air space to rear and powder forward in the case. Primer drove bullet into throat, bullet stuck then powder started burning.

    Was the S.E.E on the 1st round or was the barrel fouled from previous shots?
    Larry Gibson

    “Deficient observation is merely a form of ignorance and responsible for the many morbid notions and foolish ideas prevailing.”
    ― Nikola Tesla

  4. #24
    Boolit Master


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    Quote Originally Posted by HangFireW8 View Post
    The ballisticians I worked with at Ballistics Research Lab, APG disagree with you.

    So does the data I reduced for them.
    A lot of ballisticians believed that until S.E.E. was replicated in a lab with equipment that actually measured what was happening. I believed it as did most all the gun writers and sages not to many years distant. Some still believe the "wave" and "detonation" theories........but then some still believe the world is flat.

    Point is S.E.E has been and can readily be produced now that we understand what causes it. It was the advent of peizo-transducer measurement of the pressure curve (trace) that gave us the answer.
    Larry Gibson

    “Deficient observation is merely a form of ignorance and responsible for the many morbid notions and foolish ideas prevailing.”
    ― Nikola Tesla

  5. #25
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    Quote Originally Posted by Mica_Hiebert View Post
    Load up a rifle case with pistol h110 powder, I'll hold your beer and watch.
    I dont think that is a valid point of view. H110 may be a slow pistol powder but is a fast rifle powder.
    More accurate would be slow pistol powders in pistols and slow rifle powders in rifles.

    If you can blow a 25acp up using H110 or a 223 using H870 id like to see it
    Government is the great fiction, through which everybody endeavors to live at the expense of everybody else.

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  6. #26
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    Quote Originally Posted by jonp View Post
    I dont think that is a valid point of view. H110 may be a slow pistol powder but is a fast rifle powder.
    More accurate would be slow pistol powders in pistols and slow rifle powders in rifles.

    If you can blow a 25acp up using H110 or a 223 using H870 id like to see it
    Yet H110/W296 is used in .30 Carbine Cartridge.

    Chev. William

  7. #27
    Boolit Master

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    Quote Originally Posted by Chev. William View Post
    Yet H110/W296 is used in .30 Carbine Cartridge.

    Chev. William
    Ok, Chev.?
    Government is the great fiction, through which everybody endeavors to live at the expense of everybody else.

    Bastiat

    Non nobis Domine,
    non nobis,
    sed nomini tuo da gloriam

    Crux Sacra Sit Mihi Lux

    Tu Ne Cede Malis

  8. #28
    Boolit Master


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    Quote Originally Posted by Larry Gibson View Post
    A lot of ballisticians believed that until S.E.E. was replicated in a lab with equipment that actually measured what was happening. I believed it as did most all the gun writers and sages not to many years distant.
    Larry, I got zero of my information from gun writers or secondary sources.
    Quote Originally Posted by Larry Gibson View Post
    Some still believe the "wave" and "detonation" theories........
    There are theories. And then there is a very expensive Rheinmetall test barrel we were forced to retire after a pressure excursion. And then there is all those lovely sine waves rolling through the 8 Kistlers in the chamber, back and forth, back and forth... hard to not believe in the data, especially where the peaks coincided. And then what happened after the peaks coincided.

    It was cheap to let the new guy burn time graphing data in the hopes of saving the barrel... but not all things work out the way we plan. You see, the data just doesn't lie.

    Quote Originally Posted by Larry Gibson View Post
    but then some still believe the world is flat.
    Well now, isn't that the Larry we all know and love? How 'bout we stick to the discussion?

    Isn't is possible... that there is more than just one mechanism involved here? Perhaps I missed the narrowing of the definition of SEE and maybe, just maybe, I've gone beyond that level of discussion. Maybe we can be more than journalists, who find a source or two to quote and then stand that one point up against all other knowledge, even where such knowledge can co-exist.

    Quote Originally Posted by Larry Gibson View Post
    Point is S.E.E has been and can readily be produced now that we understand what causes it. It was the advent of peizo-transducer measurement of the pressure curve (trace) that gave us the answer.
    And my job was to calibrate, install and remove those Kistler gauges. Every P.I. had their own sets and it was my job to calibrate, track them, install them, etc.

    I noticed you completely fail to address energetic materials transcending one rate to another. But I'm no longer asking you to.

    You see, I'm done discussing SEE on this board. I no longer have access to the library at APG, and even if I did, the work we did is not publicly available to cite & be verified. And I may be done with this board. We'll have to see. I greatly dislike the quick transition to ad hominem so common in your discussions.
    I give loading advice based on my actual results in factory rifles with standard chambers, twist rates and basic accurizing.
    My goals for using cast boolits are lots of good, cheap, and reasonably accurate shooting, while avoiding overly tedious loading processes.
    The BHN Deformation Formula, and why I don't use it.
    How to find and fix sizing die eccentricity problems.
    Do you trust your casting thermometer?
    A few musings.

  9. #29
    Boolit Master Texas by God's Avatar
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    A gun can be blown up by using too much fast burning powder or by using too little slow burning powder. Half a case full of Bullseye will kaboom your 7 mag; so will half a case full of IMR 7828.
    Let's just use those loading manuals with their tested data.

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  10. #30
    Boolit Master

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    Quote Originally Posted by Larry Gibson View Post
    John

    That is the 3rd case of S.E.E. in a 45-70 that I am aware of. The other 2 were both Contenders using 2400 powder and 300 gr bullets. Same scenario; light bullet, lots of air space, muzzle raised to fire leaving air space to rear and powder forward in the case. Primer drove bullet into throat, bullet stuck then powder started burning.

    Was the S.E.E on the 1st round or was the barrel fouled from previous shots?
    The new barrel had been test fired with factory ammo before I sent it out. The first shot with the light load and it went boom. The same load in a Martini shot OK but then the gun was not pointed down to load. I had heard of detonation before but this is the first and only experience with it. I read someplace that in test they got 130,000 psi, that's a little to much for a trapdoor.

  11. #31
    Boolit Master

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  12. #32
    Boolit Master GARD72977's Avatar
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    This is the most useless thread on castboolits!!!!!!
    " If you cant do it with a 308 , you dont need to do it!

  13. #33
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    HangFireW8

    You are correct, there are more "mechanisms" at play here. However, none of them demonstrate smokeless powders "detonate" when loaded in cartridges. Yes, they (the really fast burning powders) can be made to detonate with the use of multiple blasting caps as explained in the treatise John Taylor gave in post #31. However, we are not using blasting caps to detonate the powder. We are using primers which ignite the powder to cause it to burn. The "waves" as measured by Kistler gauges do not have the velocity of the shock waves created by blasting caps.

    "Pressure excursions are easy to replicate with any "overload". True S.E.E events are difficult to replicate because certain elements or a combination of those elements must occur. S.E.E events can be easily created if we set up those elements to occur. Even then, with the elements in palce the powder does not "detonate" but burns creating a "pressure excursion" of catastrophic proportions because the bullet is not moving fast enough.

    As an example let's take a 30-06 with a max load of 3031 under a 150 gr jacketed bullet. All is fine and we can shoot that load without having any "pressure excursions". However, if we simply replace the 150 gr bullet with a 220 gr jacketed bullet under that same max load what happens? A major "pressure excursion" will happen. Does the 3031 detonate? No, it does not. Why? Simply because the heavier bullet could not move fast enough down the barrel to alleviate the pressure before the pressure reached catastrophic levels.....the "pressure excursion". The high pressure event is still caused from the 3031 powder burning, not detonating.

    I never said there weren't the "waves" measured by the Kistler gauges. I said/implied there wasn't any documented and laboratory reproducible evidence that those "waves" caused the powder to detonate. The measurement of a "pressure excursion" is a measurement of high pressure above an established norm (in this case not exceeding the structural limits of the test firearms, fixtures or barrels). That your test barrel was swollen and damaged does not demonstrate the powder detonated. The damage only demonstrates there was excessive pressure.

    I measure pressures of numerous cartridges in numerous test firearms/barrels. I have had an S.E.E. and have come close to several others. We can see the onset of an S.E.E. by the pressure traces and actual pressure reading (peak and rise of the pressure). I also have pressure traces demonstrating the "waves" as also measured by the Kistler gauges. Thus I have replicated the lab results posted in the article I quote from. I am not a "journalist". I report facts based on actual test results.

    It is unfortunate you no longer have access to the APG data. It would be interesting to see it.
    Last edited by Larry Gibson; 04-10-2018 at 09:43 AM.
    Larry Gibson

    “Deficient observation is merely a form of ignorance and responsible for the many morbid notions and foolish ideas prevailing.”
    ― Nikola Tesla

  14. #34
    Boolit Master


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    For any SEE-type event, calculate the temperature it takes to get the volume of powder-gas up to the pressure required for the failure. If you surpass the surface of the Sun, then you have to look for other explanations.

    That's a good article. I was aware of it a few years back, but it taught me nothing new. Glancing over it I find nothing to disagree with.

    OK I'm really done.
    I give loading advice based on my actual results in factory rifles with standard chambers, twist rates and basic accurizing.
    My goals for using cast boolits are lots of good, cheap, and reasonably accurate shooting, while avoiding overly tedious loading processes.
    The BHN Deformation Formula, and why I don't use it.
    How to find and fix sizing die eccentricity problems.
    Do you trust your casting thermometer?
    A few musings.

  15. #35
    Boolit Master


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    Quote Originally Posted by GARD72977 View Post
    This is the most useless thread on castboolits!!!!!!
    Since when was usefulness a criteria?
    Larry Gibson

    “Deficient observation is merely a form of ignorance and responsible for the many morbid notions and foolish ideas prevailing.”
    ― Nikola Tesla

  16. #36
    Boolit Master uscra112's Avatar
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    How can smokeless powder detonate? The molecules aren't unstable enough to be broken down by a shock wave, which is how high explosives work.

    Just as a historical datum: American WW2 hand grenades were filled with blank-fire powder, not a high explosive. They exploded just fine, but they did not detonate.
    flectere si nequeo superos, acheronta movebo

  17. #37
    Boolit Master Good Cheer's Avatar
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    Quote Originally Posted by HangFireW8 View Post
    On B, efficiency is NOT performance. Drag racers will gladly burn twice the fuel for another 0.1 second off their quarter mile. And powder blown out of the barrel may be inefficient, but it may also be the load that produces the best performance within safe pressure limits.
    In the 1980's I tried my hand at designing a cast boolit cartridge for deer hunting to work on that concept.
    Wanted the right case volume for the bore and boolit weight, an elongated pressure curve to avoid destructive plastic deformation.
    Load testing with progressively faster powders reduced the vertical stringing until plastic deformation produced lateral increases in group size. That's how I verified the powder burn rate suited to the case, the boolit and the rifle. It ended up being in the IMR4320 to 760 neighborhood with magnum rifle powders. Then the serious development began.

    That's not gonna work for people who are not working with the equipment I was working with but thought I'd throw the saga out there by the campfire just the same.

  18. #38
    Boolit Master Good Cheer's Avatar
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    Hmm, maybe I could finagle adapting that technique to working up loads for 9.3x74R.

  19. #39
    Boolit Master
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    Quote Originally Posted by jonp View Post
    Ok, Chev.?
    I have read of H110 Loads for the .30 carbine cartridge, using RN 110Grain FMJ bullets (similar to Military Ball ammo) that list charges from 80% fill to 97% fill yet The 'Warning on H110 say keep within 3% of Max Charge when using H110/W296 Propellant.

    This seems to be a Contradiction.

    Chev. William

  20. #40
    Boolit Master
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    I don't think the original poster knows enough to have a reasonable conversation on the subject.

    Some of his question can be answered by studying powder volumes powder specific gravities and powder burn rates.

    He should study loading data until he is sure that he knows the right answer.
    EDG

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Abbreviations used in Reloading

BP Bronze Point IMR Improved Military Rifle PTD Pointed
BR Bench Rest M Magnum RN Round Nose
BT Boat Tail PL Power-Lokt SP Soft Point
C Compressed Charge PR Primer SPCL Soft Point "Core-Lokt"
HP Hollow Point PSPCL Pointed Soft Point "Core Lokt" C.O.L. Cartridge Overall Length
PSP Pointed Soft Point Spz Spitzer Point SBT Spitzer Boat Tail
LRN Lead Round Nose LWC Lead Wad Cutter LSWC Lead Semi Wad Cutter
GC Gas Check