Good thread Seafire!
When I first started reloading, my mentor always told me to start with the book loads and see what happens. Sometimes you won't reach the "book max" before you get pressure signs, sometimes you can go well over. And if you have a few revisions of the manuels, you see tha the loadings change some. Not a lot, but enough to have a previously "safe book load" be over max.

Still, I usually go with the book because my most accurate loads often aren't at the top end. So while I can load more and go faster, it wouldn't improve my shooting.

quote:

Originally posted by ALF:
I use a chronograph to measure effects of pressure ......
What it does do is the measure trends....

Excellently expressed, Alf.
I once plotted velocity, energy, momentum, bullet mass, powder charge using three loadings and from that I was able to determine the expression for the powder charge, bullet mass, velocity, curve for that rifle and powder and was then able to predict 'pressure'* and velocity for any given bullet and powder charge in that rifle. (This was just a fun exercise - just to see if I could ).


* from mild to getting close to max

I use a chronograph now for reloading and for one reason alone.....to confirm I'm getting the performance I think I'm getting based on the book data. Other than that it's worthless but I consider that information valuable!

If my chrony tells me I'm getting 300'/sec less than the book I know that something is fishy and I look for what is causing it.....or just change powders! Without a chrony I'd be guessing!

I like hard data to make decisions!

quote:

Originally posted by ALF:
...In terms of the pressure curve I can show that the chamber pressure actually reaches it's peak when bullet velocity is only at 40 - 60 % of it's maximum and by the time the bullet velocity is at it's maximum the mean barrel pressure has receded to a value roughly a third of peak pressure in the chamber.

Hey ALF, I do not believe that is possible. But I am willing to try and understand "how" you came to this erronious conclusion. What makes you believe there is any validity in that statement?

quote:

As in work up my loads starting low within the safe load window I can predict with some confidence that for every increment increase in charge weight I should be getting roughly a predictable increase in FPS based on the mean V/C value as long as pressure rise remans constant.

There is the problem with the Logic, the Pressure Rise does not remain constant.

quote:

If however the measured V value suddenly starts rising from the trend it can only be at the hand of pressure and that is my cue that pressure is rising and care should be taken.

Have you ever seen the exact opposite occur - increase the Powder and you get a "Lower Velocity"?

quote:

The relationship between velocity and charge is not strictly linear, but exponential.

I disagree. No need to try and explain this because it simply isn't possible.

quote:

What it does do is the measure trends Exactly the same as for the CHE/PRE method!

Not even close!

quote:

Originally posted by 303Guy:

quote:

Originally posted by Hot Core:
.....Instructions for Measuring CHE & PRE....

Thanks for that, Hot Core. I now have your post saved in my Loading Files.

You are welcome. As you begin to use it, the Learning Curve is about 20-30min and then you should be getting excellent Pressure "Indications". Just the same as the Factories and our Elders did long before we were even born.

Let me know how it works for you.

M/

/

Well, regardless of all the theory, claims, disputes and disclaimers, one thing is for certain... understanding the properties and performance of smokeless powders in the confines of the multitude of action, chamber, barrel and projectile combinations is as easy as picking up quick silver with your fingers!

You may be able to get it in 1 puddle, but you will never be able to grasp it all!!

seafire2,

How long have you been reloading? Your post is very old news!!

quote:

Originally posted by Hot Core:
I agree with boltman that it is a miracle he hasn't blown himself up.

Sorry Hot Core, in 25 years of reloading I've never so much as blown a primer, mostly because I don't use antiquated methods like CHE that have been proven invalid by modern ballistics labs. Have you tried reading tea leaves to divine pressure? All the old timers tell me it works great for them and I'll confess that it has about the same validity.

P.S. New evidence is indicating that the world might not be flat, but don't tell the Elders, it might spook them and make them think.

quote:

Originally posted by mike_elmer:
ALF,

I pretty much agree with your dissertation. Still, for the average reloaders purposes, I believe you still forgot the issue of your data applying only the gun that you are testing. The next gun off the line will require it's own set of data to identify it's trends.

I am also curious how many shots it takes to confirm that the velocities are climbing from the trend? Couldn't we assume that by the time you identify the trend, you have already fired numerous loads that are considerably higher than safe pressure, at an unnecessary risk?

I'm not trying to flame you, ... just asking a few questions.

Mike


I agree with you Mike. Another general question (not aimed at ALF in parrticular) is "How many shots does it take at each load level to ensure that measured velocity changes aren't due simply to shot-to-shot burning variations in the powder fired in THAT load?"

Each different powder is "designed" to burn most consistently within a particular pressure range. If the load is on the light side of that range, variations from shot to shot will be higher than expected. Ditto if the pressures are above the range within which the powder is intended to burn consistently. ...and, of course, the powders are generally designed to produce those pressures within a particular case capacity range too. As certain as the fact that each rifle is different, so is the fact that each pressure curve on the oscilloscope, from each shot, is too.

As for difference in brass strengths making CHE worthless. Not so. Brass strength DOES vary within even 1 box of brass, let alone 1 whole lot, or different lots. And, of course it chages every time the case is fired and reloaded too, from such things as stress hardening, temperature influences, etc. All of these make it important to work loads up with "batches" of loads and brass as consistent as you can measure in advance...and whlie actually keeping records of what happens with each round, separately...then averaging the things you feel worth measuring.

If anyone can sort out a way to differentiate between a velocity caused by a particular pressure, from the same velocity caused by a lower pressure applied for a longer time, with a chronograph, then HAIR ON YA! I can't.

BUT, none of the above is relevant to why I seldom use a chrono in reloading. I try to be as practical as I can within my lifestyle and means.

The reasons I have rifles are to use them for specific purposes. Those reasons have NEVER included matching what velocity some other shooter or component company got out of theirs.

My objectives are to attain the best accuracy I can, long case life (and rifle life), adequate power to kill the animals I hunt, dependable gun functioning (extraction, etc., counts there too), and a variety of other sometimes lesser objectives. So, for most purposes, I am not really concerned whether my loads are within 150 fps of someone else's load. If they meet MY criteria, I am happy.

I own a couple of good chronos, including an Oehler, but I don't use them to work up loads, just to satisfy my curiosity at times.

Best wishes, y'all...

I have noticed that ALF and HotCore both make valid observations regarding pressure and velocity.

Powder burns and pressure builds to a peak or spike as the bullet begins to leave the case and engage the rifling. At that point, there is still powder left to burn, but the pressure peak has occured and it is now a matter of burning powder and gasses filling the expanding volume as the bullet travels down the barrel.

This is where powder selection becomes a prime concern.

The ideal powder in the ideal amount will provide a peak pressure that is safe for the chamber and cause a bullet velocity that follows the barrel vibration initally caused by the pressure spike.

The internal ballistics is all about timing. But it is also about repeatability. Notice, I did not say consistancy. I have personally witnessed variations in velocity that did not harm the accuracy of the load. That just tells me that velocity and standard deveation are not the "do all, be all" factors for accuracy.

I have also experienced loads where increasing powder did not increase velocity. It was usually with slow burning powders in short barrels. Makes sense.

But was that due to low pressure spikes before the bullet started traveling the barrel, or due to the bullet exiting the barrel before the remaining powder was burned?

Now add to the equation the size of the chamber, the finish of the chamber and barrel, the length of the barrel, or the internal dimentions of the case. How about the free bore in the barrel? Or the design of the throat where the rifling begins? All of these factors affect working pressures and velocity by affecting the way smokeless powder burns in confinement.

In a perfect world, powder amount will have a predicatble effect on a projectile velocity. But anyone with a borescope can tell you that perfection is not an adjective used to describe the inside of a gun.

Even with ballistics labs, the study of internal ballistics with smokeless powder still resembles the ancient practice of alchemy. That's why I like it so much!!

Alberta,

I posted before I read your post, and you hit many of the nails on the head.

It's pretty hard to think of every variable while typing a post. Everytime I think I'm done, someone else mentions a few more that I forgot!!

quote:

Originally posted by mike_elmer:
.... understanding the properties and performance of smokeless powders in the confines of the multitude of action, chamber, barrel and projectile combinations is as easy as picking up quicksilver with your fingers!

You may be able to get it in 1 puddle, but you will never be able to grasp it all!!

Quicksilver is mercury........ be careful how you handle it!

quote:

Originally posted by Alberta Canuck:
[QUOTE]Originally posted by mike_elmer:
ALF,

BUT, none of the above is relevant to why I seldom use a chrono in reloading. I try to be as practical as I can within my lifestyle and means.

You lost me on this one AC! roger

quote:

Originally posted by DaMan:

quote:

Originally posted by mike_elmer:
.... understanding the properties and performance of smokeless powders in the confines of the multitude of action, chamber, barrel and projectile combinations is as easy as picking up quicksilver with your fingers!

You may be able to get it in 1 puddle, but you will never be able to grasp it all!!

Quicksilver is mercury........ be careful how you handle it!

quote:

Originally posted by bartsche:

quote:

Originally posted by Alberta Canuck:
[QUOTE]Originally posted by mike_elmer:
ALF,

BUT, none of the above is relevant to why I seldom use a chrono in reloading. I try to be as practical as I can within my lifestyle and means.

You lost me on this one AC! roger

Sorry Roger, I could certainly have written that so it would have been easier to understand.
I was just saying that as I don't CARE what my velocities are as long as the cartridges do what I want them to do, there is no practical reason for me to use a chrono in my load development. And there is an experience reason not to.

While I am posting that last statement, let me tell a little story about why I switched from using a chrono to using CHE. It was about 45 years ago, when I only had slightly less than a decade of experience as a handloader...

I had a Hollywood brand chronograph (bought my first one in 1958 or '59). Wanted to work up some loads for a military Krag carbine I had. Decided to use 150 gr. Remington RN Core-lokts and Hodgdon's "Western Ball C " (BLC-1). Could go downstairs and look up the primers, but they were probably RWS, as I used to buy them many thousands at a time from the LA PD.

Anyway, somebody's book said that their recommended load was 39.0 grs for that bullet, and use in the Krag action. I started at 37.0 grains and worked up in 0.4 grain increments, chronographing at each step.

Things were going very evenly and nicely until I got to the recommended 39.0 grains. As that seemed okay and velocity still went up by about the expected increase, I tried 39.4 grains. Didn't blow the gun up, but sure as heck had a distorted primer pocket when I opened the bolt and the primer fell out of the case!! Needless to say, decreased the load to 38.2 grains immediately, which worked fine in the same rifle for another 10 years (until I sold it).


What happened? Well, some study on it indicates to me that I did not realize how much or how quickly powder burning rates may increase as pressure and temp increase.

Heavier charges cause more pressure AND more heat. More pressure and more heat cause the powder to burn more quickly. Burning the powder more quickly causes even more pressure and more heat. It is a classic, ascending, "vicious circle".

It turned out, as I tested that powder lot in other relatively large cases, that the pressure curve in each one typically reached a point where it was less of a curve, and more of a straight line, pointed nowhere but up. Some more research indicated to me just what HotCore said in his posts above...many of the more experienced powder geeks of that day preferred the CHE method. So I started using that, and still am.

So, short lesson here is: relying on a chrono for measuring (?) pressures got me into trouble. Using CHE as a guide never has (yet).

It is also worth noting that increased velocity is apparently not just a function of increased pressure, but of increased TRANSFER of energy to the base of the bullet. When loads get way over MAX, velocities often actually drop, and in the past some experimenters have described blowing up front receiver rings with excessive pressure loads which didn't even drive the bullet of the offending cartridge all the way through the barrel.

As someone said...it's alchemy, that's one reason it is fun.


Hang tough...

quote:

Originally posted by seafire2:
I am also posting this on the Varmint Shooting forum...so hear ya go...



Forums are always filled with armchair ballisticians, who inform we reloaders of what we should and shouldn’t do, because they read in some book or in some article.. “ Yadda Yadda Yadda..â€.. and then they present themselves as an expert on the subject, using the article or book as a reference to back them up…

Most handloading forums have no one advanced enough to make up loads.
This forum has a few.



The presentation is important too.
The way you introduced the 220 gr W748 over length, single shot, 30-30 load really drew in the reader.
You got a large following with your Blue Dot data, including me.

What does it all mean?
Keep up the good work, don't get discouraged by posts with no technical content or wit.

Well, I don't consider myself so much of an authority as I do a student. I am a student with 36 years of education behind me. I tend to be conservative because I have done most of the dumb things I ever want to do with guns. I don't use either of my chronographs to work up a load because I have seen two identical guns which developed velocities that were 12.5% apart from each other with the same loads. Maybe one gun had a barrel that was just a bit looser than the other - that might explain why one was shooting much faster than the other one. I don't need to figure it out because it tells me that there is more to the velocity than just the pressure. I work my loads up very carefully and have never had to exceed the listed maximum to find the most accurate load. In one of my guns that load is pretty close to the velocity that the books call out but most of my guns, including the two custom guns that I own, show velocities that are between 100 and 300 fps slower than the data in the books say they should be. I figure either their test barrels are loose or mine are tight or they are trying to sell their powder, bullets or whatever they are selling. I hear from the experts that after the third, or fifth, or tenth reload you should discard your brass. One book told me that I should discard my brass after the third trimming. Well, I suppose that if I was to load the way that I hear most reloaders load I might have to discard cases after five firings. I have brass that has been loaded 40 times without ever being annealed. Some might say that I am loading light charges. I like to believe that I am loading moderate charges. My hunting rifles have a point blank rang of 200 yards and hold average groups of 1/2 MOA. Some are better, sometimes a group will grow to 5/8" but they are usually smaller than that. My hunting rounds kill deer and elk effectively so I must have enough of a chage in there to do the job. If I tried to duplicate the velocities listed in the books I would not have the accuracy that I enjoy, I would be going through brass faster than a radiator repair shop, and have to own stock in the powder companies. I am no armchair ballistician and I am not the reloading police. I am just an old reloader who hasn't had a case failure in the last nine or ten years. I have built a few guns and blown up a few cases. I am lucky because the only injury I have ever sustained while shooting was a black eye from crouching up on a cheap scope. I load the way I do for the same reason that everyone else does, it works for me.
Remember; there are old loaders and there are bold loaders but there are few old bold loaders

quote:

Originally posted by ALF:
Hotcore:

I'm honestly not going to get into a mudslinging match with you, sufficed to say there is enough data and information out there , from credible sources, to support what I have stated.

As to the CHE / PRE method I have some questions and concerns about it?

1. Has it ever been validated in a lab against actual pressure measurements and if so could you please point me to where I can find the data.

2. What happens to the measurement data when cases are fired more than once ? lets say for arguement how does measurement differ between a once fired case and a case that has been fired 10 times ? The reason I ask this is that there are propellant and bullet manufacturers who argue that CHE/PRE should not be used as indicator because of the changes brass undergoes with subesequent firings or manipulations ?

3. How accurate is the measurement process in terms of inter and intra observer status ? I ask this because if the changes that occur are in the order of magnitude as dictated to by the instrument capability used for the test how reproducible is the process?

Hey ALF, I've no desire to sling mud with you either.

Since you can't answer the questions I asked about your post then it is obvious your post was pure

Best of luck to you(getting anyone to buy it.)

quote:

Originally posted by boltman:
...in 25 years of reloading I've never so much as blown a primer,

Hey boltman, That is darn good for a ROOKIE! Especially going about it the way you do.

quote:

mostly because I don't use antiquated methods like CHE that have been proven invalid by modern ballistics labs.

Now boltman you know perfectly well that is not true. But, I'll not run up the flag, because I understand you are simply trying to Defend, an impossible to defend position.

quote:

Have you tried reading tea leaves to divine pressure? All the old timers tell me it works great for them and I'll confess that it has about the same validity.

Ask them how they do it and I'm willing to try. I'm a big fan of un-sweetened Tea, so what did they have to say about it?

quote:

P.S. New evidence is indicating that the world might not be flat, but don't tell the Elders, it might spook them and make them think.

That is old news. I think maybe Bill Mac found that out. Where is he anyhow?
-----

Actually, it sounds like boltman has been over exposed to Bartsche's "Buffalo Theory". But hang in there boltman, we really don't want you to blow yourself up - or any innocent bystanders.

Paul S.

Thank you for the post. I like your core beliefs regarding safe reloading.

That said, I do use the Chrony as described earlier in order to find that one powder that gives the highest velocity with a middle of the road loading. After that, the chrony is simply confirmation of what I would expect to see while working up the load.

Intelligent choice of powder is the ideal means of avoiding the need to play in the fringes of max+ loads and disregarding published data and warnings.

Let me ask this open question to all who are reading this thread;

How many reloaders here have access to a ballistics lab to test their loads?

How many gain useful knowledge from books and articles and then apply some of that knowledge on the range? Where else would you get information?

How many here have their own firing range to test their max+ loads where no one else could be harmed by a reloading mistake?

I have read about Hot Cores method and understand the principle behind it. It makes sense in that the measurement is applied to the weakest link of the gun/ammo realationship. The only drawback is the required sensitivity of measurement outside of lab conditions.

I have used Chronographs and have seen a loose relationship between velocity and published pressures as Seafire has pursued. It means something, but it isn't the final word.

I have not used strain gauges to test my reloads, yet. The cost of that has been prohibitive to date. But if I could, I would use that as another resource of information regarding my reloads. For serious reloaders, the more information you can get, the better. But I would never loose that proverbial grain of salt!!

Now, do a search some time for "Liability of Handloaders" when using data that is not published by a recognized ballistics lab. Tell me what you find. I'm still looking for peer reviewed articles on that one!! I wonder why? Is because there are so few injuries associated with reloading? Or, is it because it is such a discreet and sensitive issue that the industry keeps it under wraps?

Finally, IF you are willing to experiment beyond the limits of published data outside the confines of a ballistics lab, and IF you are willing to put the unwitting fellow shooter at risk on a public or club range, then who is the armchair ballistician?

I don't need to criticize someone who uses a chronograph to tell if his loads have so much pressure that his brass may be affected, rather than look at the brass.

That has already been done very well by others [hot core, hot core], and is available with an advanced search here at Accurate Reloading.

quote:

So all I'm doing is to look at velocity as a function of pressure for my specific rifle and load and I look at the trend in velocity change when I alter the charge weight for my specific rifle. Is the change in velocity what is expected per increase in charge weight or is there a sudden deviation from the trend.

The above is the simplest way there is and it is also what we we have been taught by our Reloading Association. The chronograph is a useful tool. For example if you compare your gun's velocity to the Reloading Manual (for a given load and propellant) you have a base to work from. Let us assume you get an extra 150 fps then you know to approach the max book velocity carefully, as you may have a tighter chamber and/or barrel for the same type of bullet used in the Reloading Manual. Sometimes you get a lower velocity and the opposite is true.

I strongly agree with Alf that one must watch a sudden surge in the VC value - it is a very good indicator. That is why the cautious method is to suggest load jumps in half grains, and that way one is fairly safe, as we pay close attention to the normal signs that reloaders watch out for, as we step up the charge.

Warrior

quote:

Nothing could be simpler than measuring metals change dimensionally as they respond to the Effects of Pressure. Granted, only a capable Measuring device should be used or the data is worthless.

Gee, this is exactly what a strain gauge does. Measuring cases with a micrometer is somehow more accurate than something that measures stress yield in a firearm barrel?

quote:

Originally posted by jackfish:

quote:

Nothing could be simpler than measuring metals change dimensionally as they respond to the Effects of Pressure. Granted, only a capable Measuring device should be used or the data is worthless.

Gee, this is exactly what a strain gauge does. Measuring cases with a micrometer is somehow more accurate than something that measures stress yield in a firearm barrel?

If the limit of a load is the effect the pressure has on the brass, then the exact pressure is not as relevant or accurate in determining the load limit as is measuring the brass.

The trouble some people have in defining an objective reminds me of a joke:

quote:

Why can Babtists make love standing up?
Because it looks too much like dancing

What does it all mean?
They were worried that dancing would lead to sex, so they made rules.
For the process obsessed, the rules took on a life of thier own.

Kind of like people who have lost track of the difference between the effects of pressure and pressure.

quote:

Originally posted by Hot Core:
Actually, it sounds like boltman has been over exposed to Bartsche's "Buffalo Theory".

There you go again leaving the cat out of the bag. roger

quote:

Originally posted by jackfish:
Gee, this is exactly what a strain gauge does.

Ahhh..., NO!

quote:

Measuring cases with a micrometer is somehow more accurate than something that measures stress yield in a firearm barrel?

Muuuuum...., YES!

The erronious implications will not change the facts. The "Weak Link" in the firearm during actual firing is the Case. So it is where the best information can be drawn from.

No need to get third hand information, from a Haphazard Strain Gauge, which has not been calibrated and costs at a minimum $3k to get operational resulting in Bogus Data. A person can easily gather useful "Pressure Indication Information", first hand information, directly from the Case, with a Calibrated Measuring Device, at low cost to get relevant and useful data.

For an excellent source of information about the HSGS systems, anyone interested can see Dr. Oehler's comments in this link.

He basically says they are "designed for use in a Lab environment". If you do not have a Certified Lab with access to Calibration Ammo(or SAAMI Reference Ammo as Dr. Oehler calls it) then you have basically spent your money on something which CAN NOT be properly used.

Or, you can spend $30-$35 on a fine precise 0.0001" capable Micrometer and get excellent info.

quote:

Originally posted by mike_elmer:
I have noticed that ALF and HotCore both make valid observations regarding pressure and velocity. ...

Hey Mike, I'd say you got that "half right".

quote:

...How many reloaders here have access to a ballistics lab to test their loads? ...

I know a couple of Memebrs here do. However, anyone with the $$$ can contact Wyle(SP?) Labs in Atlanta and they "might" be able to perform a Pressure Test. SAAMI should be able to tell a person where they could have Pressure Testing done at a Certified Lab.

quote:

...How many gain useful knowledge from books and articles and then apply some of that knowledge on the range? Where else would you get information?...

Used to get some useful Reloading Tips a long time ago in a couple of the better magazines. Now all the writers that really understood the process are long gone. Haven't seen a "useful" Reloading Tip in a magazine in many years.

The Elders are still an excellent source, especially the really ancient, old, antique, ones like, Alberta Canuck, Bartsche, Bill Mac, Ole' Joe, Seafire, Tnekkcc, VapoDog, Woods(though he has a Thingy problem) and lots of other excellent posters that aren't quite that ancient. Lots of very knowledgeable folks on this site which makes it tough on the folks like tater-tot and ALF.

quote:

...How many here have their own firing range to test their max+ loads where no one else could be harmed by a reloading mistake?
...

I do. But with the excellent CHE & PRE data, I don't have to go that HOT to find out the Pressure is too high.

quote:

...I have read about Hot Cores method and understand the principle behind it. It makes sense ...

Well..., yes it does.
-----

Good Hunting and clean 1-shot Kills.

Alf and Boltman

I've learned the best way to deal with Hot Sh$t is to use the ignore button. He hates it when anyone disagrees with his spouting off and is dangerous to beginners and is pitiful.

You would have better luck trying to convince Al Gore that the real problem is Global Cooling. Perhaps Hot Sh$t and Gore are related!!! Could happen in the Carolinas. Remember what happens in the Carolinas, stays in the Carolinas.

Handloading without a chronograph isn't exactly a waste of time, but without one, you are missing a great deal of information.

For example, it is critical for wildcatters to use a chronograph. No starting or maximum loads are listed for our convenience/safety, and without sophisticated and expensive pressure testing equipment, how do we know where the edge of the envelope is before experiencing disaster? The load must be worked up carefully. At some point, more powder continues to raise pressure, but very little additional velocity is gained. A chronograph will indicate when they are reaching the point of diminishing returns. We look for signs of excessive pressure, but not seeing the signs doesn't mean the pressure isn't excessive. It really doesn't matter what maximum is, if it isn't worth going there.

Gentlemen,

I once was given some Mannlicher Luxus rifles, all brand new, in 270 Winchester, and asked to install scopes on them and sight them in using Norma 150 ammo.

All the rifles were identical.

The velocity difference between the slowest and the fastes was about 150 fps!!

The same lot of ammo was used.

There is nothing that guarantees ANY published data is going to be duplicated in your rifle.

Looking back on some our own experiences.

We find that soem rifles would give you higher velocity at lower charges than others.

Some would take several grains of powder more than others.

Other rifles we have had would blow primers on starting loads.

Factory ammo would normally require a hammer to open the bolt.


Getting higher velocity on your chronograph than shown in the manuals does not necessarily means you are over loading your rifle.

Rifles that have their chambers cut to minimum dimensions would normally take higher powder charges than those with sloppy chambers.

At least, this has been our own experience.

Seafire--

Thanks for an excellent post.

I didn't realize how much "each rifle is a law unto itself" could be true until recently.....

After getting quickload (which is pretty useful, but still theory for reference!), I started trying to understand what was happening with some of my loads that have worked in my rifles for 20 years of reloading.

Turns out there can be a LOT of variance in volume of factory chambers that I didn't realize or have the ability to quantify until I started measuring volume of fired cases.

This has helped explain to me how some powders and loads can be much better or worse than expected....

I am a firm believer in careful workups on my own. The better equipment and tools we have access to now only help with verification of the final product.

And as always, provide for lively discussion!


Cheers,

Dan

I see Hot Core ignores what he wants and cherry picks anything that he thinks supports his specious arguments. https://forums.accuratereloading.com/eve/forums/a/tpc/f/2511043/m/169101536/p/1

Mr. Oehler did not conclude or assert the following:

quote:

If you do not have a Certified Lab with access to Calibration Ammo(or SAAMI Reference Ammo as Dr. Oehler calls it) then you have basically spent your money on something which CAN NOT be properly used.

Ken Oehler did say: "In our experience it is sufficient to supply the M43 with inside and outside diameter of the barrel at the strain gage along with the gage constant supplied by the gage manufacurer." This is supported by ballistic strain gauge literature and practice. It is common knowledge.

Hence, a strain gauge requires no calibration, knowing the inside and outside chamber diameters at the strain gauge and the gauge factor is sufficient. Young's Modulus of elasticity, Poisson's Ratio and electrical fundamentals are all well understood in the context of getting reasonable data from the ballistic strain gauge.

I'm not going to rehash what was argued in the thread you offered. But I will say you expose your ignorance by suggesting that the only way to calibrate a strain gauge is with "SAAMI Calibration Ammunition." Nowhere in the literature is there mention of "SAAMI Calibration Ammunition" for use in calibrating ballistic strain gauges. The same can be said for SAAMI Reference Ammunition. The simple reason for this is the pressure exhibited by ANY ammunition in a SAAMI-compliant test barrel is necessarily different than the pressure exhibited by that ammunition in any barrel with differing specifications (e.g. virtually all commercially produced firearms). So, if this so-called "SAAMI Calibration Ammunition" yields 60,000 PSI MAP in a SAAMI test barrel, it will not yield that pressure in virtually a all factory rifles. So even with a strain gauge attached you cannot say the so-called "SAAMI Calibration Ammunition" produced 60,000 PSI in that firearm and you can "calibrate" the strain gauge to 60,000 PSI. The strain gauge is likely to return a pressure significantly lower than the value of that ammunition fired in a SAAMI test barrel. It is likely to return a value in PSI that is within a accepted margin of error. You haven't calibrated a thing. Indeed, no calibration is needed, only proper measurements and the gauge factor. The rest of the physics involved is known and produces the expected results. I actually find it amusing you would offer that thread as support of your arguments, as it clearly does not.

The plain truth is with a ballistic strain gauge properly set up sans calibration one can determine the pressure in PSI of any ammunition in a specific firearm within a reasonable amount of error. That is what they are designed to do.

quote:

Originally posted by TEANCUM:
Alf and Boltman

I've learned the best way to deal with Hot Sh$t is to use the ignore button. He hates it when anyone disagrees with his spouting off and is dangerous to beginners and is pitiful.

You would have better luck trying to convince Al Gore that the real problem is Global Cooling. Perhaps Hot Sh$t and Gore are related!!! Could happen in the Carolinas. Remember what happens in the Carolinas, stays in the Carolinas.

Yea, I know, but it's too much fun to watch his head spin on his neck. We just have to keep telling him that we're laughing with him, not at him.

Here's an article from the website of the makers of the pressuretrace system that details why the CHE/PRE method isn't accurate. It lays it out far better than I ever could.

http://www.shootingsoftware.com/ftp/dbramwell%20july%2019%2004.pdf

quote:

Originally posted by jackfish:
I see Hot Core ignores what he wants and cherry picks ...

Hey Jackfish, Your desire to make a point did not go down the list in that specific post very far, or to use your words, you Cherry Picked a bit too quickly. It is all there for anyone to see that follows the Link I posted.

In the same exact post(before I ever entered that thread), Dr. Oehler states , "In reality, the M43 is a research instrument and not simply a reloading accessory. (The Universal Receiver is even more dedicated to lab testing and is farther from your typical sporting rifle.)"

You will also notice he said the Universal Receiver is more dedicated to Lab Testing, which by his own words indicates the M43 is designed for use "in a Lab Environment".

No need to explain everything Dr. Oehler said, because it clearly states what I previously mentioned - but in his words.

Every thing else I mentioned is within the thread and there is no need to Cherry Pick a thing. All his comments concerning Reference Ammo(Calibration Ammo) are in the thread just as I said.

And I do understand why you do not want to "rehash the thread" because it clearly outlines " ALL " problems associated with a HSGS and verified by Dr. Oehler.
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Hey Boltman, That article you quoted was written by the same fool that offered this to the AR Board The World's Most Ignorant Reloading Suggestion. That is the guy you think knows what he is talking about? You really picked a good one there. Maybe you could get tater-tot to write something and reference it too.

There are "NO" problems associated with ballistic strain gauges if they are used appropriately. The problems associated with inappropriate use and their limitations with appropriate use are well documented for all who endeavor to employ such instruments. It is also well documented that ballistic strain gauges properly set up sans calibration can determine the pressure in PSI of any ammunition in a specific firearm within a reasonable amount of error. To say they cannot function outside of a lab environment is as inane as stating that a strain gauge will not work without calibration. All the rest of what you present is irrelevant noise.

That you actually believe you are vindicated by either the Universal Receiver or The World's Most Ignorant Reloading Suggestion threads displays your rampant delusion, as neither ultimately supports your assertions. I believe I will now join the many others who have chosen to ignore your rants. Then someone else indignant enough will carry on.

I like to look through all my currant loading manuals.I take the hottest load listed and increase the Powder charge by 10 %.

The useful measurement of pressure is the effect on the brass.

The pressure in psi is of lesser use.

quote:

Perhaps Hot Sh$t and Gore are related!!!

Teancum,

I hope this doesn't tarnish my reputation too much....

My grandmother and one of Al Gore's grandmothers were sisters!!!! so he is actually a second cousin to me...

but I never would vote for him anyway....

I've met him a few times at a couple of family reunions when I was a kid.... .back when his dad was a state senator.. who did give me a recommendation to the Air Force Academy... but I ended up not going since I wore glasses,and couldn't end up flying.. and I always wanted to be a pilot in the worst way...