quote:

Even very consistent loads, in terms of velocity, may be either consistently excessive in pressure for the long term good of your brass & rifle, or they may be consistently just into the intended low end of the burn envelope for your powder (in that case, with that bullet). If they are at the low level, no harm probably, but if you are running consistently at the top end, it may end up something like constantly driving your car with the engine revving ight up next to the the tachometer red-line. Works fine for a while, but doesn't do much for the safety of the engine.

Alberta Canuck,

What is your view in terms of excessive pressure? I see you also refer to long term effects. Should Saami/CIP max pressure levels be respected and really be seen as the top load. All the factory loads are well within industry standards whilst reloading manuals may go as high as the top end. What do you consider as a max "safe" load in terms of pressure. Since pressure is such an important discussion point with so many opinions I am curious to know how you view it.

Warrior

Careful now Alberta Canuck
The master of the badly loaded question has attempted to set you up for an argument.

Hey Warrior

What sort of advice is this?

1) Stay inside min & max loads as per your reloading manual.
You dont do this yourself. But you know better than all the manufacturers hey?

2) Work your loads up and chronograph the velocity
I dont believe this. Are you suggesting that more powder must be used and that speed must be increased? You always recommend starting loads. What happened?

3) Compare your velocity with the book velocity, so you know where you stand.
What do you do when it is much higher or much lower?

3) Check the normal tell-tale signs as you increase the loads.
Are there signs to read? A Tarot card perhaps.....

4) Try to find the rifle's sweet-spot as you are loading up.
The sweet spot only has to do with charge weight and no amount of adjustment of the overall cartridge length will change anything. Right Warrior? Oh and the rifle will only have one sweet spot never more. Right Warrior?

5) Once you find the sweet-spot there is no point in loading up
This is Warrior at his best. So let me see. If the rifle shoots half an inch at 100 with the start load which is somewhat short of the speed you want to be for the dogtown at 400 you stop right there and develop a load in another rifle with a sweet spot higher up.


6) Never exceed the max load/velocity as the incremental velocity is academic and of little practical value.
What if the rifle hits the max velocity short of the max load. Can you go up to the max load? What if the max load falls short of the max velocity? Can you work up to the max load?

7) If you stay inside the max load you will always be within Saami/CIP spec


8) In this band of min to max velocity you will experience essentially a linear relationship to pressure
For every grain you ad you will get the same increase in pressure from every grain you ad? From minimum published load to maximum published load?

WARNING - DONT TAKE ADVICE FROM THIS GUY!!!


9) If you so wish give your load to a Lab and have it tested to get a better fix at the pressure level relative to industry standards.
And once they have tested your loads they will give you a disclaimer stating that the results are only good for their test barrel and has no bearing on the rifle you have.

quote:

Originally posted by Alberta Canuck:


If one starts to get unreasonably early brass damage from his reloads, then that "load" is NOT working out, and he doesn't have a good, safe, "working", load. Again, it doesn't matter what either the actual total pressures, or the peak pressures are, it still isn't a good load. If he can, he probably needs to use more of a slower burning powder to get more velocity, at a lower peak pressure.

I guess I am only about the 4,700th person to say that on THIS forum.

Yeah but,
That is too much common sense.

Most guys on reloading forums have low intelligence, but think they are bright.

This forum may be better than most, but still....

Alberta Canuck

"Second, Mr., Gibson, if you have concluded that I am in a "camp" which does not believe chronographs are useful in handloading, you are mistaken. I DO believe chronos are useful in handloading, but I do NOT believe they are useful in telling you any substantive information about your load's pressures. In the 55+ years I have been chronographing loads, I'll bet I have done as much chrono work and interpretation as nearly anyone here. So it is barely possible I do understand how to use chronos and to evaluate the info they give me. I also undestand there is no solid, definitive, tie between velocity 6 feet from the end of a gun barrel and the peak pressure in the chamber."

I did not put you in any "camp". If you feel you belong in one or the other that is up to you. However, if you compare what I said in my post and your state of;

"Chronos certainly CAN tell you sometimes that something is off track, but as to exactly what or how much, well that is something else entirely."

you will see that we pretty much agree. No, a chronograph will not tell you much about pressure but it gives indicators that "something is off track". That, sir, is exactly what I was talking about. You just have to know enough about the indicators in conjunction with other things that indicate pressure. The chronograph is a useful tool in this regard, no?

Larry Gibson

quote:

Originally posted by tnekkcc:

Most guys on reloading forums have low intelligence, but think they are bright.
....

I disagree with this, I know I'm not bright

However in your case . . . ?

/

Hot Core

Thanks again for your intelligant response.

quote:

Originally posted by Hot Core:
[QUOTE]Originally posted by Larry Gibson:
...That is how a chronograph works for those of us who know how to use it and interpolate the data.

Hey Larry, I also wasted a good number of my 50+ years of Reloading shooting across a chronograph. That is how I know they don't tell a person anything about Pressure.

quote:

Of course the user must use appropriate references, loading componants and understand what the chronograph is or is not telling him.

I do agree with this statement, but it is only because I know a chronograph only tells Velocity - not Pressure. Stating otherwise has mislead many Beginners(and people who really don't have a clue about chronographs) to False Assumptions, Incorrct Interpolations and Totally Wrong Conclusions.

Hot Core; I'm somewhat confused, you disagree and then agree....are you sure what you mean?

quote:

The use of a chronograph is still much more accurate in developing loads (especially those loads that are not near max pressures) than is CHE or just group shooting.

I disagree completely. CHE & PRE can keep anyone out of Pressure Problems if both are used properly and together. The chronograph only tells velocity.

When loading for cartridges that max out (because of the action they are used in or other reasons) at well below the pressures where CHE & PRE give any measureable signs of what value are they then? None is the answer. However the use of a chronograph along with approprite componants will tell you when you should stop loading hotter. Granted the chronograph won't tell you the pressure but it sure as hell tells you when you are where you need to be. A classic example is the .22 Hornet in a Savage 23. When loading with H4227 and 45 gr bullets I know to stop when velocity is 2600-2650 fps. If I loaded to CHE or PRE signs velocity is up around 3000 fps and that pressure, even though I don't know what it is, is way to much for the Savage 23 action.

As to your response regarding my M43 and the use of it;

" Actually all you have purchased is Fool's Gold. If you read the questions to and answers from Dr. Oehler in that thread, he explains they are intended for Test Labratories. By that, it is clear to me that means a place that can get Calibration Ammo, or Reference Ammo as Dr. Oehler prefers to call it.....Basically that translates into any Haphazard Strain Gauge System being non-calibrated if a person buys one for use at home. And non-calibrated means misleading and worthless data."

I followed that thread and that is not at all what Dr. Oehler stated. Quite the contrary in reality.

"Best of luck with the guessed at chamber dimensions, random fudge factor adjustment, and non-calibrated M43."

With regards to CHE & PRE; what is the compression calibration of the lots of cases that you use? You don't know do you. This is exactly why it has been found that CHE can and does regularly give false or no indications of pressure.

Since accurate measurements of the inside of a chamber can readily be made I'm not sure of your point. Also when arguing a .001" error in case dimensions vs psi meaured in thousands of pound is about like arguing whether the deer was at 208 yards or 209 yards.

The "random fudge factor"? Are you refering to the 5,000 or 7,000 psi factor used as the initial pressure needed to expand the case?

"Non calibrated M43"? Are you refering to you constant quest for "calibration" ammunition? Dr. Oehler adequately addressed that. There is no such thing as "calibration ammunition". There is reference ammuntion which is different tha "calibration". Should you doubt that why don't you email SAAMI and ask them for "calibration" ammunition? Please post their response here. Actually if one shoots a sample of factory ammunition (if available) then one has a "reference" doesn't one?

I may well have "purchased fool's gold" but at least I have something which actually measures time/pressure curves. Say what you will that it doesn't but the fact remains that Dr. Oehler builds chronographs and pressure measuring equipment for the ammunition industry. He should knwo what his instruments do. The industry does which is why they use his instrument. What instruments do you provide the ammunition industry and perhaps you could also elucidate on how much paid consulting you do for the ammunition industry?

Thanks again for your many intelligent and informative remarks.

Larry Gibson

Oh, just one other thing; just how many have posted here or on other forums as to how those of us who properly use chronographs (I never said they give a measurement of pressure nor has any of the others) have "mislead many Beginners(and people who really don't have a clue about chronographs) to False Assumptions, Incorrct Interpolations and Totally Wrong Conclusions." Hmmmm....I don't seem to recall (nor has a search revealed) any of them. Could all of this just be an axe you have to grind or the calssic answer to a non existant question?

quote:

some may think I'm not worth reading because of that, but I am pretty proud of it, actually

delloro, I like the way you think. You are certainly worth reading! I have never had a blown primer nor a loose primer pocket. Nor have I blown up a firearm (thank goodness). I have, unknowingly, fired off nearly 500 rounds of machine gun ammo in my 1902 LMLE. (At a military sponsored shoot). The bolt did set back a little and the rifling near the breach is less sharp than it was and I was p!ssed-off when I discovered it (when cleaning the bore).

This thread, in spite of the 'disagreements', has been very interesting and informative!

quote:

If you believe that the case deforms ( plastic deformation) as a result of excess pressure either as a single catastrophic event or because of sustained exposure to excess pressure you have to accept that that same pressure relates to an increased velocity value albeit not as a direct relationship!

I'm glad you mentioned this ALF. I am particularly interested in the effects of a very sharp but short duration pressure rise versus a slower but lower pressure rise of longer duration versus a slower but higher pressure rise of longer duration.

I have a suspicion that the copper crusher method of pressure 'measurement' is more meaningful than direct electronic pressure measurement. (To us, anyway).

ALF, just curious, where did you get hold of the Somchem Load manual 1997?

quote:

1) Stay inside min & max loads as per your reloading manual.
2) Work your loads up and chronograph the velocity

Since the max load and posted velocity in manuals can vary significantly even with identical components,which manual do you trust?

quote:

7) If you stay inside the max load you will always be within Saami/CIP spec

Wrong.Why do you think manuals warn about working up loads if the maximum load is safe in all rifles.

quote:

9) If you so wish give your load to a Lab and have it tested to get a better fix at the pressure level relative to industry standards.

It doesn't matter what pressure the load produces in a lab,it matters what pressure is produced by that load in your rifle.

quote:

Just a question of time and we will see and accept the benefits of it - including the fact that velocity + the state of your brass are an easy observable tell-tale mechanism to the benefit and good health of us all untill such time we all accept the new ways to determine that ever important pressure.

Well said, Jagter! I do agree with what you are saying.

quote:

It doesn't matter what pressure the load produces in a lab,it matters what pressure is produced by that load in your rifle.

Respectfully it does matter. That is why all ammo companies test their ammo, because it is a good indication; not absolute if that is what you want to hear. Very few if any thing is absolute in internal ballistics. And that brings us back to the point that there is a positive correlation (please note not 100%) between velocity and pressure. The very same velocity that is responsible for causing expansion of primer pockets and case-heads (using CHE test method) is at work when we measure pressure with the copper crush method. Now we have gone full circle.

Warrior

quote:

Somchem Load manual 1997 : page 7 The importance of measuring velocity. Again a call to the relationship between pressure and velocity yield of a powder charge in a specific rifle. Not absolute values just reading what your loads are doing with velocity as you increase charge mass.

This is why we calculate the VC (velocity per charge of powder) in our rifles for a given powder, so we can compare our relative standing vis-a-vis book velocities to know if one's own rifle produce higher or lower velocities than the test barrel that was used, and so get a view on how to proceed in working loads up to the max load position in the reloading mannual.

Warrior

quote:

Respectfully it does matter. That is why all ammo companies test their ammo, because it is a good indication; not absolute if that is what you want to hear.

The ammunition companies are building a load that will be safe in all guns to avoid legal issues.The hand loader is building a load that will be safe in his gun.A load can be quite safe in one gun,yet produce excessive pressures in another gun.

quote:

Originally posted by Larry Gibson:
...Thanks again for your intelligant response.

Hey Larry, I have no problem disagreeing with folks who are mistaken in their thoughts and much prefer for the discussion to remain civil.

quote:

..Hot Core; I'm somewhat confused, you disagree and then agree....are you sure what you mean?

Yes indeed. The only way that could be misinterperted, would be if you did not understand what a chronograph is actually good for. P.S. It ONLY tells Velocity.

quote:

...When loading for cartridges that max out (because of the action they are used in or other reasons) at well below the pressures where CHE & PRE give any measureable signs of what value are they then? None is the answer.

Larry I agree there are older Low Pressure cartridges still in everyday use that CHE does not work on. In fact, that is stated in the CHE & PRE post - for anyone who bothers to read it.

However, it really appears you are using PRE improperly, because it will work with ALL Cartridges, even the old Low Pressure ones. If you would like to do it properly, check the above link.

quote:

However the use of a chronograph along with approprite componants will tell you when you should stop loading hotter. Granted the chronograph won't tell you the pressure but it sure as hell tells you when you are where you need to be. A classic example is the .22 Hornet in a Savage 23. When loading with H4227 and 45 gr bullets I know to stop when velocity is 2600-2650 fps. If I loaded to CHE or PRE signs velocity is up around 3000 fps and that pressure, even though I don't know what it is, is way to much for the Savage 23 action.

I do not mean this as "mean spirited" when I say you are drawing an incorrect assumption based on improper info.

If you were using PRE as stated in the Link, then it will Stop the addition of Powder when the PRE is the same as on the Factory round used as a Benchmark. You may actually have a Fast barrel and are not using the full potential of what you can achieve in it. Or, you may be beyond a SAFE Pressure when Velocity is used to make the decision.

quote:

I followed that thread and that is not at all what Dr. Oehler stated. Quite the contrary in reality.

"Best of luck with the guessed at chamber dimensions, random fudge factor adjustment, and non-calibrated M43."

Then you apparently "skipped over" the portion where he mentioned it is a "Labratory Instrument". Unless you have a Certified Labratory, with access to a Coordinate Measuring Machine, and Calibration Ammo from SAAMI, then your end results with the M43 will have no merit.

It is impossible to get good information when using "guessed at" chamber dimentions and a non-calibrated(to a known Standard - SAAMI Reference Ammo) System. In addition, you are instructed to add a Fudge Factor when using the M43. The folks in the Certified Labs will know how much Fudge Factor to include because of the Calibration Ammo, but without it, it is just more guessing.

quote:

With regards to CHE & PRE; what is the compression calibration of the lots of cases that you use? You don't know do you.

You are absolutely correct, I don't know. That is one of the best benefits of using it, because you do not need to be concerned about what the Pressure "actually is", only that it is enough to create measurable CHE/PRE. If it is not measurable, then it is either SAFE, the normal Operating Pressure is below CHE Pressures(but PRE will always work), or the measurements are being taken incorrectly. See the link.

quote:

Since accurate measurements of the inside of a chamber can readily be made I'm not sure of your point. Also when arguing a .001" error in case dimensions vs psi meaured in thousands of pound is about like arguing whether the deer was at 208 yards or 209 yards.

If you have a CMM, then you absolutely can get accurate Chamber Dimensions. Otherwise, it becomes a guessing game.

quote:

The "random fudge factor"? Are you refering to the 5,000 or 7,000 psi factor used as the initial pressure needed to expand the case?

No, this is a "Software Adjustment" that needs to be made with the M43 in order to get the Firearm being Tested in proper Calibration with the SAAMI barrels. You should see about it in the instructions.

quote:

"Non calibrated M43"? Are you refering to you constant quest for "calibration" ammunition? Dr. Oehler adequately addressed that. There is no such thing as "calibration ammunition". There is reference ammuntion which is different tha "calibration". Should you doubt that why don't you email SAAMI and ask them for "calibration" ammunition? Please post their response here.

Yes I am refering to my "Requirement" for appropriate Calibration of the System(firearm, Strain Gauges, wiring and the M43) to be done. Without a Calibrated System you are actually better off simply "guessing" at the Pressure because you will not have wasted the money and the "guess" will be just as accurate.

quote:

Actually if one shoots a sample of factory ammunition (if available) then one has a "reference" doesn't one?

No. The reason is because you need to know what the actual Pressure of the Ammunition is prior to putting it into use.

In order for you to use it for Calibration, it must have words to the effect, "This ammunition provides xxKpsi +or- XKpsi in a SAAMI Certified barrel."

I've not asked you any questions so far, so here is one I would like an answer to. Pick up any box of Factory ammo you believe can be used to Calibrate the Haphazard Strain Gauge System(HSGS) and tell me what the Factory Pressure is and how much variance is in it?

quote:

I may well have "purchased fool's gold" but at least I have something which actually measures time/pressure curves. Say what you will that it doesn't but the fact remains that Dr. Oehler builds chronographs and pressure measuring equipment for the ammunition industry.

I actually agree the M43 will do those measurements. And yes indeed they "are for" use by the ammunition industry - in a Labratory Environment - just as Dr. Oehler said.

quote:

What instruments do you provide the ammunition industry and perhaps you could also elucidate on how much paid consulting you do for the ammunition industry?

I'll pass, but appreciate your asking.

quote:

Thanks again for your many intelligent and informative remarks.

You are certainly welcome.

quote:

Just one other thing; just how many have posted here or on other forums as to how those of us who properly use chronographs (I never said they give a measurement of pressure nor has any of the others) have "mislead many Beginners(and people who really don't have a clue about chronographs) to False Assumptions, Incorrct Interpolations and Totally Wrong Conclusions." Hmmmm....I don't seem to recall (nor has a search revealed) any of them. Could all of this just be an axe you have to grind or the calssic answer to a non existant question?

Actually, then your Seach words were somehow incorrect. There is a steady rising group of "Experienced" Reloaders on AR who will tell folks that Chronographs only indicate Velocity - not Pressure. I've wondered about why people with Experience didn't speak up, and have decided they simply do not desire to get into the "arguments" with the folks who actually believe they can magically cipher Pressure from looking at a Velocity.

I know they are a lot of good experienced folks on this Board and more are beginning to come forward and speak up all the time - here at AR. Once they realize the Beginners, and anyone who believes Pressure can be derived from Velocity, can actually get into Pressure Problems without realizing it, then they do begin to come forward.

I can't say what is happening on other Boards because I don't bother going there.
-----

Now, what is the Pressure and Variance on that Factory Ammo???

Stubblejumper,

Here is a good example amongst the many proof loads that we sent to the Lab for testing.

Someone is using a load in his 9,3x62 mm with the 286 gr Barnes TSX bullet and we chronograped this load at 2,305 fps. He is quite happy that the load is fine. We sent is away for testing and the Lab's test barrel gave us 2,326 fps with a pressure at 108% of P-max. The velocity differential is a mere 21 fps.

Thus the perception of 'safe' in one's own gun is an elusive concept, and can thus be deceiving if it is not measured, when in fact it is actually well over the the recommended CIP P-max.

The benefit of pressure testing, even though it is in a test barrel, is to give us a reference point as we use the velocity as an indicator or a guide. This is more helpful than to assume all is OK.

Warrior

Hot Core

If you say so. We are all entitled to our opinions.

Let me ask;

Where may I obtain "calibration" ammunition from? SAAMI says there isn't any. SAAMI only knows of "reference" ammuntion. "Reference" is different from "calibration"

I will agree that chronographs only tell us velocity. Guess I'll then have to ignore everything else it tells me because you're obviously right? I don't think so. The information that comes from a series of chronographed test loads is much more than "just veloctiy". Note; I am not saying the chronograph tells pressure.

"However, it really appears you are using PRE improperly, because it will work with ALL Cartridges, even the old Low Pressure ones. If you would like to do it properly, check the above link"

I was using PRE a long time before you published your description of it. Obviously you've not tried measuring .22 Horned cases with a .0005 micrometer. At factory pressures accurate and consistant readings are impossible to get. Could be done with more sophisticated equipment but then one would need a "certified laboratory" which isn't mentioned in the link.

You make an assumption that I was using PRE incorrectly simply because it does not agree with your preconcieved ideas. "If you were using PRE as stated in the Link, then it will Stop the addition of Powder when the PRE is the same as on the Factory round used as a Benchmark. You may actually have a Fast barrel and are not using the full potential of what you can achieve in it. Or, you may be beyond a SAFE Pressure when Velocity is used to make the decision."

The fact is that with PRE and CHE you are also taking things for granted and assuming things about the pressure. When using a chronograph along with the other methods it gives you one more tool to base a decision on. After all you are making decisions based on micromter readings with CHE & PRE also. Those desisions are infact only guesses as Neither CHE or PRE gives you a hard psi number now do they? The use of factory ammuntion gives you a reference of pressure right, then why do you criticise the use of factory ammunition as a reference of pressure with the M43?. Again YOU make the erroneous conclusion that I state a chronograph tells you pressure. You are wrong.

" Then you apparently "skipped over" the portion where he mentioned it is a "Labratory Instrument". Unless you have a Certified Labratory, with access to a Coordinate Measuring Machine, and Calibration Ammo from SAAMI, then your end results with the M43 will have no merit."

Ok, who certifies the laboratories? hmmmmmm...no one because no one wants to assume liabilty for the ammunition makers in that way. So what do you mean by "certified"? Coordinate measuring machine? That's good, I like that. Calibration ammo from SAAMI? There is no such thing no matter how many times you refer to it.

Also the M43 IS calibrated when manufactured. I am not "guessing at chamber dimensions" but measuring them. There is no "fudge factor" in the instructions other than the intial pressure for case expansion. Are you telling us that there is no "fudge factor" in CHE or PRE?

So now you have got me confused. First you tell me the M43 isn't viable unless one uses "calibration ammo" to calibrate it and then you tell me it isn't viable as it uses a "fudge" factor". Then you tell me; "No, this is a "Software Adjustment" that needs to be made with the M43 in order to get the Firearm being Tested in proper Calibration with the SAAMI barrels. You should see about it in the instructions." So if the "fudge factor" puts the M43 in proper calibration with SAAMI barrels what is the problem?.

Are you sure you know what you are saying becuase I'm sure confused by your contradictions of yourself? Or perhaps your opinion says it best; "Yes I am refering to my "Requirement" for appropriate Calibration of the System(firearm, Strain Gauges, wiring and the M43) to be done. Without a Calibrated System you are actually better off simply "guessing" at the Pressure because you will not have wasted the money and the "guess" will be just as accurate." So is it the software adjustment ("fudge factor") that calibrates the M43 to SAAMI barrels or not?

How is it I state that the use of factory ammunition gives one a "reference" and you misconstrue that to mean "calibration". How is the use of factory ammuntion ok to use with PRE but not ok with the M43 as a reference? I think you really have convinced yourself that what you call "calibration ammuntion" really exists. Perhaps if you would talk with SAAMI they can straighten you out. Calibration ammunition does not exist.

"I actually agree the M43 will do those measurements. And yes indeed they "are for" use by the ammunition industry - in a Labratory Environment - just as Dr. Oehler said."

Now here you go, confusing me again. I read Dr. Oehler to say he had seen some pretty poor use of the M43 and other sophisticated pressure measuring devices in laboritories. Conversely he stated that he'd seen some pretty good use of the M43 of the tailgate of a pick up. Correct information is dependant on the correct use of the instrument not simply the use in a "laboratory envirnment". Are CHE or PRE measurements any more valid obtained in a "laboratory envirnement" than they are if obtained on a range?

You say; "all you have purchased is Fool's Gold" and that Dr. Oehler says "Dr. Oehler in that thread, he explains they are intended for Test Labratories." (incorrect as that is not what I rad Dr. Oehler to say). Then you say; "I actually agree the M43 will do those measurements. And yes indeed they "are for" use by the ammunition industry - in a Labratory Environment - just as Dr. Oehler said."

So which is it, does the M43 measure PSI or not? If it does as you've just said then unless you know the conditions of use then how is it you say it does not?

Oh, could you please give me your definition of a "laboratory environment" or "certified laboratory"? Since you decided to "pass" on responding to your qualifications for the basis of your opinions this definition will be helpful to know whether my test conditions fall within your parmeters.

"Actually, then your Seach words were somehow incorrect. There is a steady rising group of "Experienced" Reloaders on AR who will tell folks that Chronographs only indicate Velocity - not Pressure. I've wondered about why people with Experience didn't speak up, and have decided they simply do not desire to get into the "arguments" with the folks who actually believe they can magically cipher Pressure from looking at a Velocity"

Again you misinterpret what is said. Chronographs do indeed only provide velocities. However what is said is that the information provided by the chronograph over a string of tests as when working up a load (for example the average velocity, the fps variation between average velocities, the ES, the SD) provides additional information that pressure are getting there. Obviously you're having trouble comprehending the difference between using the chronograph, along with other classic indicatiors including PRE & CHE, to determine if pressures may be too high. vs just stating that chronographs tell pressure. Or as you put it "magicly cipher pressure".

Now I certainly agree with you here; "anyone who believes Pressure can be derived from Velocity, can actually get into Pressure Problems without realizing it". It is however unfortunate that you are stuck on that one train of thought as chronographs Magically ciphering pressure" is not what is said at all. It is only your interpretation of what is said.

It is also unfortunate that you've closed off your mind to reason and understanding of what is really being said. Yes numerous "experienced" handloaders have come forward. Those who use chronographs and those who don't. I take a grain of salt from those who do not use chronographs who criticise their use because they percieve no need to use one. It is many of those who we hear from whenever this topic comes up on this forum or any other forum. Perhaps if they used them correctly they would change their minds, perhaps not. Doesn;t make them wrong or right now does it? Just means they've an opinion.

You have a nice day.

Larry Gibson

quote:

Originally posted by Warrior:
Thus the perception of 'safe' in one's own gun is an elusive concept, and can thus be deceiving if it is not measured, when in fact it is actually well over the the recommended CIP P-max.

True. That's the difference between measuring pressure and divining it with tarot card, ouija board, and rings around the moon remedies.

Another issue is that handloaders often have different ideas of what is "safe", some of which bear no resemblance to anything that the industry would recognize. You understand the significance of P-max. but it's amazing how many handloaders don't. They're the same guys that believe that modern handloading manuals have a built in legal liability "fudge factor" in the listed max loads.

quote:

The benefit of pressure testing, even though it is in a test barrel, is to give us a reference point as we use the velocity as an indicator or a guide. This is more helpful than to assume all is OK.

Of course, otherwise handloading manuals would be useless. In the old days (not very long ago) data in handloading manuals was a mixture of data developed in crusher guns, or in off the rack "test rifles" in which max loads were determined by observing classic pressure "signs", measuring "good old time proven CHE & PRE", and the like. It didn't work as well as they thought it did. In the quantum leap in the accuracy of electronic testing technology that's taken place since then, a lot of those max loads were discovered to be more than just a little bit over SAAMI/CIP max. That's the reason for the difference in old vs new data that so many have written off to "lawyer padding".

CHE/PRE doesn't quantify pressure. It can't. A chronograph doesn't either, but in following the GUIDE of a given set of components and a specific propellant as pressure tested in modern, tight SAAMI/CIP spec pressure guns, it's an important tool. As always, some will prefer to live in the past.
-----------------------------------------------
"Serious rifles have two barrels, everything else just burns gunpowder."

Hey Warrior
I did some Gooooooogle work like you are fond of doing and found more than 10 loads for the 9.3x62 with a 286gr bullet that exceeds 2350fps and some getting over 2400fps. Nosler Norma Barnes RWS and Vihtavoiuri all list loads that are in that league. Maybe your lab is suspect?????? Maybe you are suspect????

quote:

found more than 10 loads for the 9.3x62 with a 286gr bullet that exceeds 2350fps and some getting over 2400fps.

Rat Motor,

You are actually on ignore, but your ignorance compelled me to share this with you. You have only one gun and thus it tells us about your wealth of reloading experience.

The Lab testing speaks loud and clear. I referred here to the 286 gr TSX bullet, not to an array of other 286 lead-core bullets, but specifically to the TSX which is a monolithic bullet. Somchem also do not have loads for this bullet. Another reason why we did the testing. To measure is to know.

Further more, all the 286 gr bullets give different pressures as their construction differ from conventional, to partitioned, to partitioned and bonded, with different wall thickness and diameter differences, and length of bearing surfaces, etc. All their 'shot start' pressures are also different. The TSX is thus unique in its own way just like the GSC-HV. Then each powder with its specific burn rate would yield its own pressure charateristics. We used S355 as it gave us better results than S341 with 286 gr bullets.

I prefer to believe the results of the lab rather than yours, as to what is suspect and what not.

Warrior

Hey Larry, Just read your post and I need a drink!

Since you did not answer my single question to you, don't expect me to continue answering your nonsensical questions.

Best of luck to you and your Fool's Gold.

quote:

Originally posted by Warrior:
Stubblejumper,

Here is a good example amongst the many proof loads that we sent to the Lab for testing.

Someone is using a load in his 9,3x62 mm with the 286 gr Barnes TSX bullet and we chronograped this load at 2,305 fps. He is quite happy that the load is fine. We sent is away for testing and the Lab's test barrel gave us 2,326 fps with a pressure at 108% of P-max. The velocity differential is a mere 21 fps.

Thus the perception of 'safe' in one's own gun is an elusive concept, and can thus be deceiving if it is not measured, when in fact it is actually well over the the recommended CIP P-max.

The benefit of pressure testing, even though it is in a test barrel, is to give us a reference point as we use the velocity as an indicator or a guide. This is more helpful than to assume all is OK.

Warrior

That is the kind of thinking that is pervasive on the internet.
The load works in the gun, but that person's mind was has a higher priority of fear that the pressure is higher than a rating.

The 9.3x62 has the same Mauser case head that is rated for 65kpsi in a 270, but should not be. Newer cartridges like the 260 Rem are only 62,000 psi. That is becuase factory loads have a hard time getting near 65kpsi without some primer pockets loosening in some rifles.

But if someone has a rifle and a load and they work, why fear a pressure measurement?

Because of an inadequate understanding of the relationship between the guns strength and the brass strength. Somehow the belief in pressure measurements has interfered with the learning of that relationship.

This view is common on internet, and it is probably caused by starting out with load books and recipes, and having a faith in the load book. This causes a "load book fundamentalism".

What is safe and what is not safe is based on what is unknown. Those with this fear of pressure load book fundamentalism suffer fear from the unknown. They have faith in load books and laboratory measurements of pressure and the recipes that follow. When outside of this religious structure, they think the demons of pressure may attack. They do not have the field of reference of overloading guns to see what happens. They try to live inside the tenants of their load book cult.

There is no way to educate these people, and no way to outnumber them.
The trick is to accept them and their faith as valid for them.

quote:

Originally posted by Hot Core:
Hey Larry, Just read your post and I need a drink!

Since you did not answer my single question to you, don't expect me to continue answering your nonsensical questions.

Best of luck to you and your Fool's Gold.

If you are refering to this question (only one in your last post);

"Pick up any box of Factory ammo you believe can be used to Calibrate the Haphazard Strain Gauge System(HSGS) and tell me what the Factory Pressure is and how much variance is in it?"

First of all we disagree on your continued use of "calibration". I stated in the last post and the previous one that the use of factory ammo gives you a "reference". It does not give you "calibration" of which "calibration ammunition" is non-exhistant. But then you know that don't you which is why you avoid the discussion or have not contacted SAAMI to find out. Or perhaps you have found out but don't wish to admit the error.

At ant rate I am not entirely avoiding the question. I shall tell you what the factory pressure is in my rifle (actually two rifles chambered in .308 Winchester will be used) in PSI. Unknown what you mean by "variance"? I expect to conduct a test later in the week and will post the results here for all to see - any particular flavor of factory ammo you'd like to know about?

Actually I never expected an intelligent answer to my "nonsensical questions".....as that would prove embarassing to you perhaps? A drink would be good actually, think I'll have one too. Cheers!

Larry Gibson

quote:

Someone is using a load in his 9,3x62 mm with the 286 gr Barnes TSX bullet and we chronograped this load at 2,305 fps. He is quite happy that the load is fine. We sent is away for testing and the Lab's test barrel gave us 2,326 fps with a pressure at 108% of P-max. The velocity differential is a mere 21 fps.

First of all,you are assuming that you can directly convert velocity to pressure which can't be done.Secondly, was the load fired at the same temperature,barometric pressure and humidity in both guns?Were the chamber dimensions,barrel dimensions,and rate of twist identical in both barrels?Was the surface finish of the bore identical in both barrels?If all of these factors were not identical,assuming that the same chamber pressure will produce the same pressure in both is not an accurate assumption.

/

quote:

You are measuring velocity which is a function of pressure!

Assuming that because a load produces the same velocity in two guns,the pressure must also be the same is not an accurate assumption.

Hey Warrior

quote:

You are actually on ignore

I knew you were too nosey too put me on ignore. Just like having the last post on any subject you will find a reason to crawl back. (Insect analogy)

quote:

You have only one gun

It is a rifle not a gun and I do not see your point. Schumacher only had one Ferrari. Ernie Els only has one putter. By comparison I am not in their league when it comes to reloading but you get the point I hope.

The thing is we can see and hear when we see and hear it and you are full of it.

quote:

I prefer to believe the results of the lab rather than yours

Not my results you fool. They are from labs that have been around much longer than your mickey mouse lab.

I like the way tnekkcc describes you

quote:

That is the kind of thinking that is pervasive on the internet.
Somehow the belief in pressure measurements has interfered with the learning of that relationship.
This causes a "load book fundamentalism".
When outside of this religious structure, they think the demons of pressure may attack.
They try to live inside the tenants of their load book cult.
There is no way to educate these people,

Have you noticed that not many members here agree with you.

quote:

If all of these factors were not identical,assuming that the same chamber pressure will produce the same pressure in both is not an accurate assumption.

Stubblejumper put it better than what I could. Some of us are learning and retaining a small amount of what is posted on these forums but it looks like you dont. My knowledge of reloading has increased by leaps and bounds since I have lurked and posted here but the you come up with is just amazing.

quote:

What is safe and what is not safe is based on what is unknown. Those with this fear of pressure load book fundamentalism suffer fear from the unknown. They have faith in load books and laboratory measurements of pressure and the recipes that follow. When outside of this religious structure, they think the demons of pressure may attack. They do not have the field of reference of overloading guns to see what happens. They try to live inside the tenants of their load book cult

Tnekkcc,

When we talk about safe maximums it inter alia applies to all circumstances and not just ideal circumstances. That implies then that there must be a margin of safety rather than on the brink of an absolute maximum. It should thus cater for things like powder lot to lot variations, ambient temperature differences, altitude differences, exposure to direct sunlight (some times for long durations), dimensional bullet differences in bullets in the same weight category (e.g. conventional PMP bullet vs Swift A-Frame and anything in between), dimensional differences in chambers & barrels, softer actions vs actions made from modern steel, etc. The safe load should be good for sustained and extensive use so metal fatigue and lug set-back is not a possibility.

Again when we talk 'safe', how big should this margin of safety be? On the brink all the time or 5% or 10% lower than 'something'. Now, what should this something be? An arbitrary something left to the opinion of the non suspecting public and novice reloaders? Could this something actually be a standard laid down by a Lab or Proofhouse? Could it be CIP? Safety standards in factories work essentially the same way when we insist that safety precautions will be taken, will be adhered to and you will be disciplined if not - that is how we fix discipline and run according to a system. No one is saying that disaster will happen if we do not rigidly abide, but the potential is there and this very probability is what we are trying to avoid for safety reasons.

It is obviously your right and prerogative as an individual to set your own safety standards, but they may not necessarily apply to the public at large. You will find that there was a valid reason if you go into it why the CIP max is 56,500 psi for the 9,3x62 and not 62,000 psi or 65,000 psi even though you say case is similar to the case of the 270 Win. If not, then we have to assume that the CIP regime suffer from the same ignorance.

Warrior

I use a chronograph and PRE in an attempt to keep my load development within a "safe" operational window. Having said that, I don't believe for one second any combination of the above mentioned could possible give a pressure reading, but I do believe they provide an approximate "whereabouts" as to pressures. These "measurements" are repeatable, and when lot number integrity amongst components and consistent hand loading practices are maintained, they can be duplicated.

Warrior,
You are right there needs to be safety margin.
The weak link in the 9.3x62 rifle is the brass.

A load is worked up until the brass fails.
The powder charge is then reduced for a safety margin.

The pressure did not matter if it was 60 kpsi with very soft brass or 80 kpsi with some super brass.


Strong rifles do not get metal fatigue or lug set back at or near the limit of brass Mauser case heads.
[But if you need to fear that, or things like that, I understand your condition. It is very common.]



I have more ammo of this load, but I think I will back off on the powder charge.

No lug set back or metal fatigue yet.

Everything if going per plan.
I will have lots of safety margin, and do not live in fear of pressure.

quote:

Originally posted by Larry Gibson:
...I shall tell you what the factory pressure is in my rifle (actually two rifles chambered in .308 Winchester will be used) in PSI.

Actually you won't be able to tell me what the Pressure is, that is the entire problem - because you won't know.

I realize that is confusing to you just as the rest of the Facts and Reality I mentioned to you previously.

quote:

Unknown what you mean by "variance"? ...

Oh yes Larry, you REALLLLLLY know what you are doing.

I now understand you know less about it than denton and I would have bet that was impossible.

HSGS = Reloaders Pyrite(aka Fool's Gold)

/

Hot Core

That's the type of response I expected from you. Thanks anyway.

Larry Gibson

Hey Larry, Let me suggest this to you since you believe I don't know what I'm talking about.

I would encourage you to call around to a Manufacturing Facility in your area and ask to speak with their Quality Assurance Manager. Ask him if he knows any company in your area that uses Strain Gauges as a regular part of their manufacturing operation, or as part of their maintenance.

Once you find a place that does use Strain Gauges, ask them if they use them as part of a Calibrated System. And is the Calibration traceable to a National Standard.
-----

I really don't think you are dumber than denton, just mislead. But your mind is made-up and you are not interested in hearing a view to the contrary from someone who used Strain Gauges for a very long time.

I do(seriously) wish you the best of luck.

Talking about having a standard, CIP is attempting to be a universal standard for the very reason to set a common approach and standard in testing ammo and the issuing of firearms specifications. Most European Manufacturing Facilities subscribe to CIP as well as South Africa.

Warrior

quote:

Originally posted by Hot Core:
Hey Larry, Let me suggest this to you since you believe I don't know what I'm talking about.

I would encourage you to call around to a Manufacturing Facility in your area and ask to speak with their Quality Assurance Manager. Ask him if he knows any company in your area that uses Strain Gauges as a regular part of their manufacturing operation, or as part of their maintenance.

Once you find a place that does use Strain Gauges, ask them if they use them as part of a Calibrated System. And is the Calibration traceable to a National Standard.
-----

I really don't think you are dumber than denton, just mislead. But your mind is made-up and you are not interested in hearing a view to the contrary from someone who used Strain Gauges for a very long time.

I do(seriously) wish you the best of luck.

Hot Core, you are a mighty warrior with great spirit!
I don't know what you're talking about half the time, but you are on fire

1) Denton is pretty smart at read the chapter and answer the questions at the end. His problem is with common sense, fear, bad manners, ego, and close mindedness. [There is a term that sums up these traits succinctly.]

2) I don't think QA knows anything about traceability of measurements to NBS, but calibration and test engineering may know a little.

3) I have strain gauges and I occasionally design instrumentation amplifiers. Getting a meaningful reading of pressure near the end of a tapered tube with tapered inside diameter with a strain gauge pasted on catywupas is a recipe for out of control error. [your barrel is not in Roark's book of Formulas for Stress and Strain on weird shapes]

They will tell you to get some calibration ammo to calibrate it.

This reminds me of a joke.
A dumb kid asks a smart kid how he can get smart too.
The smart kid takes him under the rabbit cage and picks up a rabbit dropping. He tells the dumb kid, "Eat one of these smart pills every day and you will get smart."
A year later they cross paths and the dumb kid yells, "I've been eating one of those smart pills every day for a long time, and I'm beginning to think they're rabbit turds!"
The smart kid responded, "See, you're getting smarter already."


What does it all mean?
calibrated ammo = smart pills

quote:

Originally posted by Hot Core:
Hey Larry, Let me suggest this to you since you believe I don't know what I'm talking about.

I would encourage you to call around to a Manufacturing Facility in your area and ask to speak with their Quality Assurance Manager. Ask him if he knows any company in your area that uses Strain Gauges as a regular part of their manufacturing operation, or as part of their maintenance.

Once you find a place that does use Strain Gauges, ask them if they use them as part of a Calibrated System. And is the Calibration traceable to a National Standard.
-----

Thought it was I who has been asking you all along to call SAAMI (after all we are talking about ammunitio here and not instumentation of amplifiers) and get their answer on "calibration ammo". Now you are asking me to just ask any local business who might use a strain guage for whatever purpose? You call SAAMI and get their answer then we'll talk about it as the ARE the "National Standard" for what we are discussing.

Since tnekkcc doesn't know where a strain guage is attached on a barrel or what the parameters are for it's location it is no wonder he is unsuccessfull with their use. I'm quite sure the local designer of "instrumtation amplifiers" is the resident expert on "calibration ammunition".

You two are killing me, think I'll go have a drink.

BTW Hot Core; I ran some tests of Winchester and milsurp .308/7.62 and 30-06 ammo today. It was quite interesting and informative. The pressure figures are there in PSI and they match all other published data of expected PSI with that ammunition. A couple of my cast bullet reloads proved also interesting. Too bad your mind is closed. Others will appreciate the information though.

Larry Gibson

Larry, did you get the part about Roark and the end of the tube?
Do you know how to trace to the NBS?


Can you skip the insults and show your math?
Or is that all you've got?


You are suffering from the meaningless measurement syndrome, and I am willing to help you work through your issues.

Start out with the change in resistance of the gauge and get to psi, and show your error budget.

I think you will find there are some missing links in your understanding.

What does it all mean?
Show me the math, Larry.

quote:

Originally posted by tnekkcc:
...1) Denton is pretty smart at read the chapter and answer the questions at the end. His problem is with common sense, fear, bad manners, ego, and close mindedness. [There is a term that sums up these traits succinctly.]

Well, I've changed my mind again - Larry is obviously dumber than denton.

quote:

2) I don't think QA knows anything about traceability of measurements to NBS, but calibration and test engineering may know a little.

Agree with Calibration and Test Engineering being the place. I was always in Product Evaluation Engineering and they reported to us everywhere I worked. If they are seperate in other places as you mention, I just wasn't aware of it.

quote:

3) I have strain gauges and I occasionally design instrumentation amplifiers.

Larry is not going to let anyone with years of first-hand experience confuse him with the facts(aka denton)

quote:

Getting a meaningful reading of pressure near the end of a tapered tube with tapered inside diameter with a strain gauge pasted on catywupas is a recipe for out of control error. [your barrel is not in Roark's book of Formulas for Stress and Strain on weird shapes]

You might as well be talking to a mule. But, it sure is nice to see someone take denton's place. Should be good for a lot of grins.

quote:

They will tell you to get some calibration ammo to calibrate it.

Imagine that!

quote:

This reminds me of a joke.
A dumb kid asks a smart kid how he can get smart too.
The smart kid takes him under the rabbit cage and picks up a rabbit dropping. He tells the dumb kid, "Eat one of these smart pills every day and you will get smart."
A year later they cross paths and the dumb kid yells, "I've been eating one of those smart pills every day for a long time, and I'm beginning to think they're rabbit turds!"
The smart kid responded, "See, you're getting smarter already."
...

And Larry would say, "These smart pills go realllllly well with my HSGS results.

A non-calibrated, guessed at dimensions, Haphazerdly placed Strain Gauge, fudge factored HSGS = Reloaders Pyrite(aka Fools Gold) - and the data is realllllly good when taken with Rabbit Pills!
-----

By the way tnekkcc, since the thread has gone all to clinton, I recently had another fellow mention to me how well he likes the Mueller Scopes. And I saw some in the large Grafs catalog - nice prices.

quote:

Originally posted by tnekkcc:
Warrior,
You are right there needs to be safety margin.
The weak link in the 9.3x62 rifle is the brass.
A load is worked up until the brass fails.
The powder charge is then reduced for a safety margin.
The pressure did not matter if it was 60 kpsi with very soft brass or 80 kpsi with some super brass.
Strong rifles do not get metal fatigue or lug set back at or near the limit of brass Mauser case heads.
[But if you need to fear that, or things like that, I understand your condition. It is very common].

It is well known that many custom rifles have been built and still are being built on the Argentine 1909 Mauser action. We know that their receivers are relatively soft and it has been discussed right here on AR. They do suffer lug set-back at higher pressure. This also happens with other military K98 actions that were produced during the latter part of WWII. Mauser K98 actions were not designed for high pressure cartridges when the action was "perfected" in 1898. That is why these actions are better suited for cartdiges with lower pressures such as the 7x57 mm, 8x57 mm and the 9,3x62 mm - your typical German calibers. Even so, caution should still be your priority not to load too hot.

Imagine all reloading manuals propagate your system:

A) A load is worked up until the brass fails.
B) The powder charge is then reduced for a safety margin.

Principally this doctrine does not specify a top load nor a top velocity as it is superfluous.
In fact the system is so open that it should not even limit one to a recommended powder.

Warrior