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Thread: S.E.E. loading data, need help

  1. #61
    Boolit Man Paul5388's Avatar
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    No, the nuclear material was just an illustration. Here's a few things I found regarding explosions.

    The presence of hydrogen gas in air can present a serious risk of explosion. An overheated container of dry nitrocellulose is believed to be the initial cause of the 2015 Tianjin explosions.

    One unusual phenomenon occurs when dense, low-volume powders are used in large-capacity rifle cases. Small charges of powder, unless held tightly near the rear of the case by wadding, can apparently detonate when ignited, sometimes causing catastrophic failure of the firearm. The mechanism of this phenomenon is not well known, and generally it is not encountered except when loading low recoil or low-velocity subsonic rounds for rifles. These rounds generally have velocities of under 1100 ft/s (320 m/s), and are used for indoor shooting, in conjunction with a suppressor or for pest control, where the power and muzzle blast of a full-power round is not needed or desired.

  2. #62
    Boolit Master


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    Paul5388

    That theory of "detonation" of smokeless powder is older than we are.......and has been disproven. We now know what the cause of an S.E.E. is. It is not "detonation" of a smokeless powder. Dredging up all the old unproven theories guessed at before the cause was found is not going to disprove what we now know is the cause.

    Larry Gibson

  3. #63
    Boolit Master
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    Quote Originally Posted by Larry Gibson View Post
    Paul5388

    That theory of "detonation" of smokeless powder is older than we are.......and has been disproven. We now know what the cause of an S.E.E. is. It is not "detonation" of a smokeless powder. Dredging up all the old unproven theories guessed at before the cause was found is not going to disprove what we now know is the cause.

    Larry Gibson
    Larry, how about a link to proof of the cause for those with poor search ability or slow internet service to prevent taking hours or days to find the definitive cause. Not trying to question your statement, just trying to avoid sorting through lots of off topic cr*p looking for the information.

    Went back through this thread, found references to previous thread, but no link. Reference to Handloader article, but no link. Is there a single, valid explanation of this phenomenon?
    Last edited by ulav8r; 02-23-2017 at 01:51 PM. Reason: Added text in red.

  4. #64
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    Handloader article;

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    You should be able to save the picture to a file, then open and enlarge. If you can't read it I will rescan and attempt another post.

    Larry Gibson

  5. #65
    Boolit Master


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    Actually, here's the narrative of the article;

    Handloader- readers havedoubtless heard of a term called secondary explosion effect (S.E.E.). It is atheory that attempts to explain the catastrophic failure of some rifles whilefiring seemingly reasonable handloads or reduced loads using slow-burning powders.Theories have been offered and debated in these pages and elsewhere, but theyhave been just that, theories, because no one has been able to reproduceeffects under laboratory conditions. Thepurpose here is not to debate S.E.E. but rather to report on a specificincident and the results of tests done to discover the cause of catastrophicfailure.

    One of the great problems withattempting to theorize on the cause of catastrophic failures is that we must doso after the fact. We have the corpse, usually with someparts missing and must try to figure out what went wrong. Learned theories areoffered, sometimes conflicting, and we end up with a bunch of folks shouting inprint, 'You're wrong.' "No, you’re wrong." Since the event they'rearguing about what without benefit of instrumentation, either one could beright. The events I describe here represent the first instance of an eventproduced under controlled laboratory conditions and documented on industrystandard pressure measuring equipment that provides a plausible explanation offeredto explain S.E.E.

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

    In early 1989 a major manufacturerbegan development of a load for the 6.5x55mm Swedish that was to be added to theirproduct line. Development was uneventful and all work was done using the coppercrusher pressure measuring system, for there were no standards established for piezo-electricpressure measurement in the 6.5x55mm. Thecopper 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 isno way that one can deduce what is happening during the period the powder isburning, nor can one see other significant ballistic events.

    A quantity of ammunition wasloaded using a relatively slow-burning, non-canister propellant with a140-grain bullet. After load development in ammunition manufacturer’s pressureguns, it is common practice to function test ammunition in a variety ofavailable rifles to ensure satisfactory performance before it is released forsale to the public.

    As function testing of the6.5x55mm ammunition was begun using Swedish Mauser rifles, they noticed some ofthe same signs of excess pressure every handloader is taught to look for -flattened primers, enlarged primer pockets and heavy bolt lift. All theammunition fired in the pressure gun had been perfectly acceptable, but SAAMItest barrels and chambers are made to tightly controlled specifications so thefirst supposition was that some element within the test gun was contributing tohigh pressures. Then a "spontaneousdisassembly" occurred that destroyed the action but left the barrel undamaged.The bore was clear and showed no bulges. It was immediately identified as ahigh pressures failure and an investigation was begun. The barrel from the wreckedMauser action was fitted with a collar that allowed it to be mounted in auniversal receiver, and an industry standard conformal piezoelectric transducerwas installed. Another test was performed using the Oehler Model 82 piezoelectricpressure measuring system equipped with a trace hold oscilloscope.

    (Fig !)
    round pressure (psi)velocity (fps)
    1 48,8202,601
    2 53,8492,662
    3 57,6092,708
    4 57,9992,720
    5 54,0932,687
    6 58,6342,731
    7 62,1502,754
    8 82,1202,875

    Pressure tests are commonlydone with a 10-round string and as you can see from the chart, pressuresincreased very gradually on rounds I through 4. At the fifth shot, pressure droppedand then continued to increase until, at the eighth shot, pressure, went to82,120 psi; and the technician wisely stopped the test. The raw data was thenused to prepare additional graphs (fig. 1) which show that, after ignition,pressures dropped momentarily to near zero on the graph before beginning torise again.

    To interpret this data we haveto first understand the ground rules applicable to pressure testing withconformal transducers. The key term here is 'offset" which relates, primarily,to the specific cartridge and the brass used therein and must be determined foreach transducer and lot of brass. The offset is the amount of pressure requiredto 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/pressurecurves produced in the test; we must understand that we are not actually seeingpressures 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 somewhereat or below the offset pressure. All we can say for sure is that, at thispoint, the pressure is <3,800 psi. Engineers calculated that for thespecific bullet being used it would take pressure of at least 5,000 psi just tokeep the bullet moving.



  6. #66
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    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 largethere 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. Thiscan only be attributable to a deterioration of the throat and leade on that particular barrel. In this instance SAAMI standard barrels were used andshowed 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.

    Larry Gibson

  7. #67
    Boolit Master


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    Here are the factors we now know that cause an actual S.E.E. (not to be confused with an overload);

    S.E.E. Factors

    "Although there does seem tobe a correlation with the use of handloaded ammunition, they are very hard toattribute to any principle factor, even when the rest of similarly loadedammunition is available for examination"

    I would have to disagree to the extent that we now know what the attributablefactors are inherent in or leading up to an actual S.E.E. event. Whennumerous of those factors are present we can presume (that's all we do afterany event has already happened) that an S.E.E. occurred if there is noindication of any other external cause (such as a cleaning rod/tip left in thebore).

    There are 9 basic factors to consider when determining if the event was anS.E.E.. The first 2 are measurable only during the event with peizo-transduceror strain gauge pressure measuring equipment. The other 7 can be observedafter the event. It is those seven we base our conclusions on as the anevent was an S.E.E. event or not. Most often in actual S.E.E. events wewill find at least 4 or 5 of those factors readily apparent. Many times,and probably why S.E.E. events are actually rare is that if just 1 or 2 of thefactors are not present the event doesn't occur.

    An S.E.E. event can come close sometimes though. How many times have we hadquestions pondered on this forum that during a test string one primer (perhapsmore) was extremely flattened showing excessive psi signs while the otherprimers in the test string did not? I recall just such a recent questionasked on this forum. Have you ever had a load that you've used for a longtime all of a sudden give a bit of brass flow back into the extractorhole/slot, especially on a cold day?

    Anyways the 9 factors of a probable S.E.E. event are;

    1. A distinct dip in psi very shortly after the rise in psi begins. It takes approximately 5,000 psi to keep a jacketed bullet moving. Theactual amount is variable dependent on bullet fit, jacket hardness, bearinglength and bore condition. If the dip in psi is below 5,000 psi thebullet is probably stopped or stopping.

    2. A measured increase in peak psi progression as rounds arefired. This progression may be gradual to a point and then exhibit alarge jump in psi. The increase may also be very quick with few roundsfired.

    Note; the first 2 factors are only measurablewith proper test equipment. Since most S.E.E. events occur without theuse of test equipment these two factors are not discernible.

    3. There is a long throat in which the bullet moves a relativelyconsiderable distance before engaging the leade (rifling).

    4. There is an eroded throat that essentially causes a combination of #3along with a rough surface causing greater resistance to bullet movement.

    5. Fouling. This can be from any number of reasons; primer residue,unburned powder, insufficiently burned powder residue, bullet jacketfouling, etc.

    6. Case neck tension. Minimal case neck tension on the bulletallowing the force of primer ignition alone to push the bullet out of theneck into the throat.

    7. Bullet Hardness and bearing length. Obviously the harder thebullet and/or longer the bearing surface the more psi required to keep thebullet moving. Also a softer bullet that readily upsets may also increasethe psi required to keep it moving.

    8. Barrel temperature. as more rounds are fired the psiincreases. This increase can be especially large if the cartridge is inthe chamber for a time prior to be fired. An analogy here would beleaving the round in the hot sunshine prior to firing.

    9. Large chamber neck and chamber over case dimensions. Allows morespace around the neck and body of the case for gas to expand into beforepsi is sufficient enough to expand the case and seal the chamber. 5,000to 7,000 psi are necessary to expand most rifle cases to seal a chamber. The larger the chamber in relation to the case the more psi is required over alonger time. If the bullet is pushed into the throat with5,000 or less psi by the primer the psi drops as the gas expands into theincreased volume before the powder begins to burn efficiently.

    Again in our investigations of catastrophic firearm failures we should lookfirst for external an cause for the event such as shooter error (wrongammunition, continuing to fire after an apparent misfire, leaving a cleaningrod, tip or patch in the bore, not checking the bore prior to shooting for anobstruction, etc.) or reloading error (wrong powder, wrong powdercharge as in too much, wrong size bullet, etc.). We look for the externalcause first because it is most often the reason for the catastrophicfirearm failure. If we can eliminate the probability that an externalcause was not the reason then we look for an internal cause; is the firearmitself suspect?

    If there is no evidence of an external cause or a firearm defect it isthen we look for an S.E.E. event. We look for a combination of probably4+ of the above factors to be present. If 4+ of those factors (3 through9) are present we can conclude in all probability the event was anS.E.E.. If we have been measuring the psi with a peizo-transducer orstrain gauge and we have factors 1 and 2 present also the proof is ratherpositive a S.E.E. event occurred.

    We can sit around and theorize all we want but at some point a decision can bemade, based on scientific readily reproducible factors, as to whether acatastrophic firearm event was an S.E.E. or not. The above are thefactors found in a firearms lab while conducting tests of a suspect lot offactory 6.5x55 ammunition. I have found, when measuring psi with anOehler M43, some of these very factors to occur. I have stopped testing,based on those factors as did the lab technicians, prior to actually creatingan S.E.E. event. These events can be "readily" produced. That does not mean they can be produced at will each and every time yet with alittle effort an S.E.E. can be produced. I can, without muchproblem, by just varying test loads produce the 1st 2 factors. No notevery time but often enough I pay attention to the psi and time/pressure tracesas I test/develop loads.

    The German report stated with the .243 Winchester they could produce acatastrophic event 1 in 6 times......that's 3+ times out of a box of 20shells..........some might not consider that as "readily" but Ido.

    Larry Gibson


  8. #68
    Boolit Man Paul5388's Avatar
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    "S.E. Effect wrecked a strong Universal Receiver and broke the Pietzo-electric Transducer (able to stand ten thousands atmospheres of peak pressure !). Test was repeated with another Universal Receiver and pressure test-barrel: Again "KA-BOOM !" Universal Receiver was ruined and the Transducer broken once again."
    "It was a rare event, when S.E.E. was REproduced purposely. It happened in West-Germany in the late 1960s or early 1970s. Whole story is told on a book: "Handbuch für den Wiederlader" by Dr. K.D. MEYER. This load of NORMA MRP was and is completely safe, if it is topped with 90 gr or 100 grains bullet."

    I suppose the time period of 1960-1970 makes this a prehistoric event? Whatever, it still goes against what you have postulated by destroying universal receivers.

  9. #69
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    Apparently you're not understanding what you're reading. S.E.E. events have been occurring for a long time, probably as long as small bore large capacity cases and slow burning powders have been around. Are you thinking this is new? I recall reading about it in magazines as far back as the late '50s. First S.E.E. events I heard/read about involved the 25-06 when it was still a wildcat and several other over bore .257s and 6mms being loaded with surplus 4831. I used to have a Shooter's Bible from the late '50s or early '60s with an article of an S.E.E in it.

    It was with the advent of the peizo or informal transducers and their use by firearms and munitions manufacturers in the late '60s and early '70s that a complete picture of internal ballistic happenings were being actually understood instead of theorized upon. The occurrence you refer to is in complete agreement with the finding of the laboratory in the Handloader article. I don't understand what your reference to the time period ("late 1960s or early 1970s") has to do with the cause of an S.E.E. event?

    The German test findings concur with the test finding in the Handloader article.

    Larry Gibson
    Last edited by Larry Gibson; 02-23-2017 at 11:34 PM.

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    As I was reading through all the posts on this thread, I got to wondering about something. A little explanation as to why I was wondering is the fact that I run a top fuel dragbike. This bike makes in excess of 1200 horsepower from 90 cubic inches. It is supercharged nitromethane, thus the power level. Early on, I had problems with the exhaust valve guides getting so hot from exhaust gasses exiting the valves, that the ends of the valve guides were actually melting. It was bad enough that the valves were showing transfer of the Ampco bronze welding itself to the valve stems.

    I'm wondering if some of the copper metal jacket fouling in a barrel may be caused by the same effect of hot gas melting a small portion of the jacket and welding it to the barrel. Could this possibly contribute to a bullet sticking very briefly in the throat and possibly contributing to this effect? It wouldn't necessarily show up as being a problem with a fresh barrel, but may contribute if the throat or lead had become deteriorated to the point of being rough or burned away. It was mentioned in an earlier post that a less than fresh barrel was noticed in some of these pressure excursions, and I'm wondering if this could be a contributing factor.

    If so, could a coating such as the moly coating that is sometimes used by benchrest guys possibly help in this situation? I know that's a stretch, but ?????

  11. #71
    Boolit Man Paul5388's Avatar
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    DuPont was using piezos as early as 1964 in their loading data and maybe before.The issue I was addressing was the universal receivers blowing up.

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    Larry has the truth. Boolit movement that stops and then ignition. it is simple, primer pushes the boolit to a stop and powder goes off with a bore obstruction. Run through all theory's about powders lead to nothing.
    Just why do I use a standard primer in the .44 mag? The mag primer will push out the boolit too soon. You do not have a revolver gap in a rifle. Pressure hits the stuck boolit and reverses.

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    I agree 100% with what 44man has just stated!!!

  14. #74
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    Quote Originally Posted by Paul5388 View Post
    DuPont was using piezos as early as 1964 in their loading data and maybe before.The issue I was addressing was the universal receivers blowing up.
    Yes, the use of peizo transducers began in the '60s and has become prevalent the last 20 years in the industry. Some manufacturers still use the copper crusher method though. It's why we still see psi's listed as CPUs and PSI's. A lot of knowledge has been gained since then and the technical development of the means of measuring psi and the digital software has been vastly improved.

    Why would a "universal receiver" not be susceptible to damage and/or destruction from such a catastrophic event such as an S.E.E.? Particularly when a conformal peizo transducer is used which would be a real weak point in such a catastrophic event?

    Larry Gibson

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    [QUOTE=Larry Gibson;3963168]Yes, the use of peizo transducers began in the '60s and has become prevalent the last 20 years in the industry. Some manufacturers still use the copper crusher method though. It's why we still see psi's listed as CPUs and PSI's. A lot of knowledge has been gained since then and the technical development of the means of measuring psi and the digital software has been vastly improved. Larry he"s new and I don"t think he has a clue as to what your credentials are (for real) !
    Last edited by Edward; 02-24-2017 at 04:21 PM.

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    Larry he"s new and I don"t think he has a clue as to what your credentials are (for real) !

  17. #77
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    fast Ronnie

    Hard to say about any of the jacket getting "welded" to a rough throat. To my knowledge there has not been a bullet recovered from a barrel after a S.E.E. event. The psi does get to the point where the bullet gets moving again and is shot out of the barrel. However, by then the psi has reached catastrophic levels and at such high psi's the powders burning rate is increased. However, that is not to say some jacket material, particularly from a previous shot(s), may be gouged/scraped off by the rough fouled throat and may indeed contribute to the bullet getting stuck in the throat.

    Larry Gibson

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    Quote Originally Posted by Edward View Post
    Larry he"s new and I don"t think he has a clue as to what your credentials are (for real) !
    Edward

    Hopefully, while we try to explain, he'll keep an open mind and learn as we all have......heck, 30+ years ago I bought off on all the theories about waves and detonations too.....then I paid attention to the new discoveries backed up by scientific testing and proven results. It's just a matter of learning is all.

    Larry Gibson

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    Comparing Nuclear energy to reactive energy from powder? Not going to comment on S.E.E because I know only enough to ask questions and also while I know little to nothing about building Atomic bombs I do know that comparing a nuclear detonation to a chemical detonation is taking the "Apples&Oranges" comparison to whole new levels! There certainly would be enough pure energy in even one grain of any kind of powder (or even a grain of sand for that matter) to destroy a .308 action or even a heck of a lot more IF we were talking about converting matter into it's energy form at the molecular level! Converting matter into energy by splitting atoms is in no way even remotely related to the energy potential of something like smokeless powder undergoing a chemical conversion even if that conversion reaches the speeds at which it could be considered a detonation. I don't know how much energy burning 3 grains of Bullseye, for instance, could produce under the best (or worst depending on point of view) of conditions but I doubt it could damage a .308 receiver, a tiny fraction of that however would vaporize the receiver and anything around it if it could be converted to pure energy at the molecular level like happens in an atomic chain reaction but that simply ain't going to happen under any circumstances!!!
    Statistics show that criminals commit fewer crimes after they have been shot

  20. #80
    Boolit Master
    Join Date
    Oct 2010
    Location
    fairbanks
    Posts
    8,661
    bump........

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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