quote:

Originally posted by El Deguello:

quote:

If one knows that a certain factory load produces 2,700'/sec and when doing the load developement one reaches the 2,700'/sec, then it is an "INDICATION" that he is nearing (or exceeding) the SAAMI max for that round as it's reasonable to assume that the factory is loading to the best performance they can (safely)

This would only be true if the powder being used was from the same lot that was in the factory loads, and the load was put up in new, unwork-hardened brass from that same factory lot, and the bullets and primers as well.

Larger quatities of slower powders can and do produce higher velocities at lower pressures even when the cases, primers and bullets are the same, provided enough of the slower powder can be gotten into the case. Dangerous pressures can be easily produced with fast powders long before the maximum potential velocity for a given cartridge and bullet are reached.

Trying to be helpful instead of argumentitive...

When I have a third, higher charge group give a lower velocity, there is usually some other factor at work that I have overlooked. Sometimes it means I have shot the first two groups and then took a longer break (allowing the barrel to cool more)....or it might mean I have reached a point where I am adding significant compression to the powder charge.

I like the chrono for additional data, but don't believe it gives me pressure data. Unfortunately, if something seems too good to be true it usually has been....

Cheers and good shooting,

Dan

quote:

Originally posted by Hot Core:

quote:

Originally posted by CDH:
I see that yet another thread has degenerated into the old HC vs. the world and pressure argument. ...

If you consider you dutch
and tailgunner "the World", then it does appear you would be correct. Otherwise, most folks in the thread are leaning toward the "you can NOT determine what the Pressure is from a Velocity" and of course they would be correct.

I dunno how you lump me in that group...I have never made such a claim and know better. My simple stand is that pressure is one of many factors affecting velocity. As has been (accurately) mentioned, if one duplicates a book load and gets unusual velocities it is a warning sign. Yes, there I said it, unusual velocity is a warning sign for high pressure. Now normally this statement is enough to send you over the edge, so let me add the HC qualifier (which should be obvious to most of the rest of the world). Note that this does not necessarily work in reverse, low velocity is not necessarily the result of low (peak) pressure.

The simple fact I was pointing out is that your argumentativeness and twisting or dismissal of factual information becuase it doesn't suit your narrow spectrum of highly qualified or disclaimer filled parameters is silly, and argumentative. It will lead to the arbitrary dismissal of your (frequently good) advice by the very newbies you claim to want to protect.

quote:

Originally posted by Tailgunner:
I refuse to be dragged down to your level of fool, as you will beat me with your years experience.

ROFLMAO
That is an irrefutable fact. Jim

You cannot determmine pressure from velocity is correct. However if you are shooting a book max with a suitable powder and your velocity is 200 fps slow, the pressure will be low as well. If it is 150 fps faster, your pressures will be high as well. Like a lot of other things, it doesn't identify pressure, but velocity and pressure are mathematically directly related, in other words increase pressure= increase in velocity and vice versa.

It’s hard to argue with an idiot without becoming an idiot yourself. Let the thread die.

This reminds me of an old saying about communications.....

"I know you think you know what I said, but what you don't know is that I didn't say what I meant!"

Discussions of pressure seem to follow the logic in that statement!

Without entering the debate too deeply (my big rubber boots are in the garage)....I will say I won't develop loads without my chrono. I could....but I won't. It's a tool that used intelligently...... gives....intelligence.

Jstevens, you said it your self! Backed off a bit for best accuracy or max or even a touch above depending on the rifle, chamber size, bore size, bullet used, powder used, etc. But what if you get the best accuracy at, say one gr over max but your velocity is lower then the book says it should be at max. Do you push the envelope trying to reach the higher velocity when you are already over max?
I have never mentioned .223 velocities in a .220 swift and would be extremely angry if that was all I could get. 30-06 velocities in a .300 Weatherby is ludicrous. There is a point where the rifle YOU have will shoot best and still give very good velocities without exceeding safe pressures. That was not the point of this post. The point was to match book figures by adding more powder, exceeding safe limits to achieve speed that can't be reached in most rifles. My point is that if the gun is very accurate and shoots great at 50 or 100 fps lower then the book says, leave well enough alone. A starting load for any caliber increases as the case size gets larger and the max is also higher. Some where in there is the most accurate load. Find it first and leave the chrono at home until you are happy with the way the rifle shoots. A starting load for a .300 is not going to give 30-06 velocities. A starting load for a .220 is not going to give you .223 velocities.
To depend on the chrono until primers blow or the gun blows trying to get those book figures borders on insanity.

/

quote:

There is a direct relationship between MBP ( mean barrel pressure) and projectile muzzle energy based on Bore diameter.

Mean barrel pressure (or mean anything) can be a deceiving statistic. Sort of like the statistic about putting one foot in boiling water and one foot in ice water. Based on the average you are comfortable. MEAN barrel pressure for a given load of Bulleye in a bottle neck rifle cartridge might give normal exterior ballistics. However the pressure peak above the mean may burst the barrel.

bfrshooter

If it were a 7Mag, yes I would probably bump it up, but carefully. I have loaded for a lot of different ones and have personaly seen the loads vary by 4-5 grains, between individual rifles. The 7Mag is a rifle that you sure as heck better start low and use common sense and watch for all the pressure indicators as they vary widely. I have also seen the same thing with other calibers, but this one is the worst. I load 72 RL15 in a .375 H&H and the 270 grain bullets go 2750 fps. A bunch of the guys here are loading 72 grains behind a 300 AFrame. It would be a big problem in my rifle. They are all different. I usually like to get within 100 fps or so of normal ballistics with a cartridge, other than that velocity doesn't matter.

Been out killing a bunch of dogs, so I've been a bit busy.

quote:

Originally posted by Tailgunner:
Dr Oehler partialy agreed with you, in that there is no absolute calibration for pressure (regardless of methiod), however he strongly disagreed with you on PRE & CHE as being better than a properly applied strain gauge. ...

And this was the PM to tailgunner:

quote:

Originally posted by old amiable Hot Core:
Hey Tailgunner, I went back to the thread where I was discussing the HSGS with Dr. Oehler and can't find where he "strongly disagreed" about CHE/PRE. Perhaps I'm just overlooking it. I'd appreciate it if you would give me a direct quote(or link to the spot) so I can go see it.
Here is the Link to the Thread.

-----

Can anyone locate where Dr. Oehler "strongly disagreed" with CHE/PRE, or has tailgunner gotten into a dentonesque mode of making up something when the truth/facts interfer with his inaccurate beliefs?

You forgot the rest of your childish/female/lawyerish rant, so here it is for all to see. Your also forgetting that the former Nosler ballistician also told you the same thing, but that's par for you.

quote:

Originally posted by Hot Core:
Hey Tailgunner, I went back to the thread where I was discussing the HSGS with Dr. Oehler and can't find where he "strongly disagreed" about CHE/PRE. Perhaps I'm just overlooking it. I'd appreciate it if you would give me a direct quote(or link to the spot) so I can go see it. Here is the link to the Thread.
---

While I have your ear, which Method do you think is best based on these questions?

1. Do you need to Haphazardly measure a chamber? Advantage - PRE or HSGS?
2. Do you need a $10 throw away Strain Gauge? Advantage - PRE or HSGS?
3. Do you need to glue anything to your rifle? Advantage - PRE or HSGS?
4. Do you need wires in the way to fumble over? Advantage - PRE or HSGS?
5. Do you need a computer to make it function? Advantage - PRE or HSGS?
6. Do you need a long System Set-Up at the Range? Advantage - PRE or HSGS?
7. Do you take Data directly from the Case or third-hand through a Strain Gauge? Advantage - PRE or HSGS?
8. Do you spend more than $30 for the Pressure Detection Method? Advantage - PRE or HSGS?
9. Does it take more than 20min to learn to operate? Advantage - PRE or HSGS?
10. Is it possible to Calibrate the Measuring Device to a Known Standard? Advantage - PRE or HSGS?
11. Does it take a truck to carry, or is it similar in size to a box of cartridges? Advantage - PRE or HSGS?
12. Do you establish a Comparative Benchmark Standard using Factory Ammo? Advantage - same-E-same
13. Do the Test Cases get to a point(work hardening) that they can mislead the user? Advantage - HSGS!
14. Does either Method allow the user to quote misleading, inaccurate, Pressure in Kpsi? Advantage - PRE or HSGS?

I forgot these when I originally posted:
15. Which is easier to use when measuring Pressure Effects on each Chamber of a Revolver? Advantage - PRE or HSGS?
16. Which is easier to use when measuring Pressure Effects on a Semi-Auto Pistol? Advantage - PRE or HSGS?

Do you see any clear Advantage to one of the above Methods over the other?

Sometimes I'm a little careless in what I say or post, and I definitely cannot remember what I said. I appreciate many of you honoring me as the authority regarding pressures and velocities, but perhaps there has been just a little name exposure.

What I meant to say is that our chronographs used properly will give an accurate and reliable measurement of velocity. These measured velocities can be used as indicators of uniformity [possibly accuracy] and performance [if average velocity is a true measure of performance]. When relating velocity to pressure, I customarily stop with the statement something to the effect that "An average velocity in excess of published factory velocity is a very good indication that you have exceeded factory average pressure." I make absolutely no claims that velocities lower than factory velocities indicate pressure lower than factory levels or that it is safe to increase the charge until you reach factory velocity levels.

I've been aware of CHE/PRE for years and find few advocates among those who have actually measured pressures using either a piezo conformal or gas system or even a properly used Model 43. I personally consider the CHE/PRE system to be a refined method of observing that you have likely passed the factory maximum average pressure. It certainly won't tell you when you are approaching factory max ave pressure, or how far you have exceeded the max ave pressure. Piezo transducers and the Model 43 can give you a reasonable measurement of pressure even though the measurement is not perfect.

I believe that Hot Core's reasonable defense of CHE/PRE is that his system has prevented him from blowing up any rifle in his years of experience. That proven result is laudable, but it does not qualify CHE/PRE as a measurement of pressure. In my opinion it illustrates a controlled infringement into the safety margin intentionally left by SAAMI. Others may want to work there, but I choose to avoid the region.

I'll certainly admit that I can't shoot long-range groups with David Tubb or measure cases as well as Hot Core. Just because I can't do something doesn't mean that they can't.

Are there others out there who have actually measured pressures with conformal transducers or a Model 43 along with observing CHE/PRE? Maybe I'm all wrong.

KenO

quote:

What I meant to say is that our chronographs used properly will give an accurate and reliable measurement of velocity. These measured velocities can be used as indicators of uniformity [possibly accuracy] and performance [if average velocity is a true measure of performance]. When relating velocity to pressure, I customarily stop with the statement something to the effect that "An average velocity in excess of published factory velocity is a very good indication that you have exceeded factory average pressure." I make absolutely no claims that velocities lower than factory velocities indicate pressure lower than factory levels or that it is safe to increase the charge until you reach factory velocity levels.

I'm not sure this can be stated any better or more clearly!.......a well written post!

/

quote:

Originally posted by Tailgunner:
You forgot the rest of your childish/female/lawyerish rant, so here it is for all to see. Your also forgetting that the former Nosler ballistician also told you the same thing, but that's par for you. ...

No, I intentionally left it out. Posting Facts concerning CHE/PRE seems to cause a lot of mental stress for the dentonites, so I saw no need to "further" stir them up.

Interesting that you are still unable to answer any of the questions. I'd "guess" the truth is either too embarrassing to your foolish positions or you simply don't understand a thing about the subject.

Nosler guy? Mr. Joe? I agree that I do not remember what you are talking about - again. I'll freely admit my memory is not as good as it used to be. So, if you could provide a Link to what you are talking about, it would be quite helpful.

But I suspect that you are simply "fabricating" another line of foolishness. Darn shame you have absolutely NOTHING at all positive to offer to the thread.

Best of luck to you.

quote:

Originally posted by Dr. Oehler:
... I appreciate many of you honoring me as the authority regarding pressures and velocities, but perhaps there has been just a little name exposure.

I’d suspect it is because you have always provided excellent products and excellent support for those products. It speaks volumes for a person to run a Company well enough that the product is always bragged on.

If I was wanting a chronograph(which I don’t), I would be quite upset that you no longer offer a product that just measures Velocity. Yes, I can see where the Printer Option would be nice for some people, but if it was me, I’d much prefer to simply remove a "512k SD Card" from the (Hot Core Model) Oehler once I got home and plug it in the computer. Then Update a Reloading Database(which came with the Hot Core Model) and print out whatever I wanted to. The less complicated the chronograph is at the Range, the better I’d like it – similar to the OLD Oehler MODELS.

quote:

What I meant to say is that our chronographs used properly will give an accurate and reliable measurement of velocity. These measured velocities can be used as indicators of uniformity [possibly accuracy] and performance [if average velocity is a true measure of performance]. When relating velocity to pressure, I customarily stop with the statement something to the effect that "An average velocity in excess of published factory velocity is a very good indication that you have exceeded factory average pressure." I make absolutely no claims that velocities lower than factory velocities indicate pressure lower than factory levels or that it is safe to increase the charge until you reach factory velocity levels.

Totally different from the “just keep dumping it in†folks. I see now some of them think it is still OK to tell folks that, as long as only a small portion of 1% of the Rookies get blown to smithereens. Pitiful.

quote:

I personally consider the CHE/PRE system to be a refined method of observing that you have likely passed the factory maximum average pressure. It certainly won't tell you when you are approaching factory max ave pressure, or how far you have exceeded the max ave pressure.

After all the discussions we have had, it appears I finally disagree with you about what CHE/PRE can and does allow the Reloader to know.

CHE is less informative than PRE, simply because it takes much more Pressure to see the “effects†of it on the Case. In older low Pressure Cartridges, CHE is useless because current manufacture Cases do not always expand in the Case Head at the Pressure levels those old cartridges were designed for.

However, PRE always works and will easily allow the user to see when he is “approaching factory max ave pressure†when it is done properly. He will know when he is well below Factory Pressure, approaching it, or exceeding it. But, it must be done correctly.

I do agree with you that a PRE user does not know what the actual Pressure happens to be. And I’d say the exact same thing about a HSGS System that requires the user to “guess†at the chamber dimensions, Haphazardly apply a Strain Gauge, enter some arbitrary Fudge Factor and not be able to Calibrate the overall Strain Gauge System to a known Standard(or Reference Ammo as the situation might be).

As a person who’s opinion I respect(but don’t agree with all the time) once told me, the HSGS has the potential to be off by 8%. That still seems rather small to me with all the potential for Tolerance Stacking and Fudge Factoring errors. How that can possibly be thought of as providing any degree of confidence in whatever the LED says in relation to "Pressure" eludes me.

quote:

I believe that Hot Core's reasonable defense of CHE/PRE is that his system has prevented him from blowing up any rifle in his years of experience. That proven result is laudable, but it does not qualify CHE/PRE as a measurement of pressure. In my opinion it illustrates a controlled infringement into the safety margin intentionally left by SAAMI. Others may want to work there, but I choose to avoid the region.

Then I’d suggest the Procedure you base your assessment of the value of PRE on was perhaps incorrect. If a person follows what is outlined in this link to CHE/PRE, they should be able to get excellent data from PRE. CHE as well "if" the cartridge is operating at a high enough pressure.

quote:

I'll certainly admit that I can't shoot long-range groups with David Tubb or measure cases as well as Hot Core. Just because I can't do something doesn't mean that they can't.

I don’t believe Mr. Tubb would have to buy many BBQ Suppers when shooting against me either. I'm too old to even give him a drop of sweat.

However, there is no reason you can’t learn to read a Micrometer as well as I do. Granted I’ve been doing it for a few years , but if you choose to try the above procedure, you can leave all that HSGS fiasco at home.
-----

The Reloading world deserves a simple old style (Hot Core Model) Oehler Chronograph without a printer and definitely without the HSGS. Who ever your Marketing guy is really needs to WAKE UP and smell the gun powder.

Good Hunting and clean 1-shot Kills.

So I take my rifle to the range.
I work up until it has problems.
That may be .001" expansion of the extractor groove, which will not cause the primer to fall out, but is an indicator of the threshold of brass failure.
I back off 6% like Vernon Speer said in 1956.
I now have enough safety margin so that the primer will not fall out at some important time.

If I just keep going up in a work up until the primer falls out, it is more dramatic, but not an important milestone in finding a usable load.

If I can work up a load until the primer fall out of the pistol cartridge with chamber walls .1" thick, I will not have hoop stress failure at the threshold of the primer falling out of a rifle cartridge with the chamber walls .5" thick.

What did I need a chronograph for?
1) Bragging about my 4,200 fps .223
2) Seeing which powder gives the most velocity.

The pressure limit of primer pocket growth I measure with dial calipers on the extractor groove. This works better than pin gauges in the primer pocket.

How is a chrono going to tell me where the limit of the brass is?


Or is the problem someone is afraid to go to the limit of the brass?

I have done it in 100 different guns, and it is not that scary.


But with severe overloads, when a primer pocket doubles in diameter, it takes allot more hammering to open the action on a Howa than it does on an M70, K98, Sav 99, AR15, Handi Rifle, 91/30, M39, M44, Stevens break action .410, or Ruger #1.

quote:

So I take my rifle to the range.
I work up until it has problems.
I back off 6% like Vernon Speer said in 1956.
I now have enough safety margin so that the primer will not fall out at some important time.

What did I need a chronograph for?
1) Bragging about my 4,200 fps .223
2) Seeing which powder gives the most velocity.

The pressure limit of primer pocket growth I measure with dial calipers on the extractor groove. This works better than pin gauges in the primer pocket.

How is a chrono going to tell me where the limit of the brass is?


Or is the problem someone is afraid to go to the limit of the brass?

First off....excellent photos....well done and points well made!

A few replies to your questions:

quote:

Or is the problem someone is afraid to go to the limit of the brass?

Yes.....I truly believe that many folks are not willing to go the "full nine yards"...nothing wrong here but many will quit early in developement.

quote:

What did I need a chronograph for?

I, once worked up a load using BL-C(2) in a 22-250 or a friend....the load was listed by Hodgdon and I had the powder and used it solely because I had it.

The performance was noticeably poor on a prairie dog town and then I chrono'd them at less than 223 velocities.....I then loaded new rounds using H-414 and walla.....the 22-250 sung well again.
The BL-C(2) loads didn't come close to the data published by Hodgdons at all!

Had I used a Chrono, I'd have known that this was the wrong powder for this gun!

quote:

Originally posted by tnekkcc:
[
So I take my rifle to the range.
I work up until it has problems.
That may be .001" expansion of the extractor groove, which will not cause the primer to fall out, but is an indicator of the threshold of brass failure.
I back off 6% like Vernon Speer said in 1956.
I now have enough safety margin so that the primer will not fall out at some important time.

If I just keep going up in a work up until the primer falls out, it is more dramatic, but not an important milestone in finding a usable load.

But with severe overloads, when a primer pocket doubles in diameter, it takes allot more hammering to open the action on a Howa than it does on an M70, K98, Sav 99, AR15, Handi Rifle, 91/30, M39, M44, Stevens break action .410, or Ruger #1.

When it comes to your pressure effect testing you are still my idea of an engineer's engineer. You are truely a caped crusader. roger

Now please get rid of that flame thrower!!!!!!!!

When you guys get into this argument I wonder how many of you have been gassed by a blown primer. It also reminds me of the Sarco employee that was killed a few years ago shooting a 6mm Lee Navy.

quote:

Glenn De Ruiter, a well-known resident expert at Sarco in Stirling, New Jersey, was killed in an accident at the range at Easton Fish & Game in Pennsylvania shooting a 6mm Lee straight-pull.

quote:

Glenn was involved in a tragic accident on Saturday, June 29th when his 1895 Remington Lee Rifle exploded. He was taken to St. Luke's Hospital in Bethlehem, PA, but was not able to recover. He was 54.

Glenn was a devoted employee of Sarco for 28 years, and specialized in military firearms. He had a tremendous love for guns and was passionate about his work. He was among the most well respected and knowledgeable people in the industry. Glenn was good friend and he will be missed.

quote:

On this same date, June 8, 1992, I interviewed Glen Deruiter, manager, Sarco
Inc., Stirling, New Jersey, and learned from him that in May of 1992 their
company shipped one M-16 parts set kit with a sling and magazine to the
"Mag-Bag" in the name of David Koresh. The total value of these items was
$284.95.

quote:

Man dies after rifle explodes

Blast in barrel of gun at shooting range fatally injures N.J. resident.
By Joe McDonald Of The Morning Call

July 1, 2002

A New Jersey man died after his rifle barrel exploded while he was
target shooting over the weekend at the Easton Rod and Gun Club in
Northampton County, authorities said Sunday.

The accident happened Saturday at the club's Lower Saucon Township
firing range at 11:30 a.m., said Lehigh County Coroner Scott Grim.

There was an explosion in the barrel of the rifle that Glenn deRuiter,
54, of 268 W. Portal Road, Bethlehem Township, Hunterdon County, was
firing, Grim said.

The blast sent out shrapnel, and one piece hit deRuiter in the head,
Grim said.

DeRuiter died at 2:30 p.m. at St. Luke's Hospital, Fountain Hill, Grim
said.

Grim, who ruled the death an accident, said the malfunction happened in
the rifle's receiver ring.

Neighbors learned of deRuiter's death Sunday night.

''Everyone is in total shock,'' said neighbor Beverly Graczyk, the mayor
of Bethlehem Township, about 40 miles east of Allentown.

''All of us are just gasping and trying to recover,'' she said.

Dairy farmer Bernie Beatty is another neighbor.

''He was a wonderful man, a wonderful father,'' Beatty said. ''I just
saw him the other day. He was always working in the yard, doing
something.''

DeRuiter also was a gun enthusiast, Graczyk said.

''He had quite an extensive gun collection,'' Graczyk said. ''I believe
he worked for a company that manufactures firearms.''

DeRuiter and his wife, Joan, who is a teacher, have lived in the
township for about 20 years.

''Glenn was a quiet, very nice man,'' Graczyk said.

''They are the kind of people you really want for neighbors, to be part
of the community. He was just a really good guy.''

Graczyk said she knew deRuiter's wife through her efforts to save the
Asbury Bridge, which Graczyk said was a ''wonderful antique'' with iron
tresses.

''She fought hard to save that bridge,'' Graczyk said. ''But the county
wouldn't listen and put up a new ugly one.''

As word of the accident spread through the township Sunday night,
Graczyk said, ''This is a tough one Å  really, really hard.''

I spoke with Glenn on the phone in 1996, he was the manager at Sarco, and I was asking about returning an Australian heavy FAL parts kit with blown gas block.

quote:

Originally posted by vapodog:
The BL-C(2) loads didn't come close to the data published by Hodgdons at all!

I find this very intriguing. Have you thought of a cause? Could your powder have been off?

If the Oehler Marketing Crew is watching the thread, I've got a couple of other Mods you can add to the "Hot Core Model".

Add a tube inside the Rail that the Sky Screens are mounted on which will allow the use of a Lazer Bore Sighter to be put in it. This would help get the Sky Screen/Tripod set up. Then the same Lazer can be removed and used in the Firearm's barrel to make sure the person isn't going to Blast the Sky Screens.

Eliminate ALL wires running to the Sky Screens. A simple short range transceiver would exchange the data between the Sky Screens and the Base.

Best of all though, would be to design a CHE/PRE measuring device into the Base. Just stick a Case into a port and let the Hot Core Model measure both the CHE and PRE. Only real problem with this design is that if it is implemented properly, it would totally obsolete all the Haphazard Strain Gauge Models from every manufacturer.

quote:

Originally posted by JAL:

quote:

Originally posted by vapodog:
The BL-C(2) loads didn't come close to the data published by Hodgdons at all!

I find this very intriguing. Have you thought of a cause? Could your powder have been off?

No I have never found the cause......I just assumed that BL-C(2) is much too fast for the 22-250 and was a wrong powder to use regardless of the fact that Hodgdon showed it in the loads.

I bought this up as a reason to use a chronograph in reloading....one can be deceived without it

.......but to Hot Core's defense, it's vital that the data be used in context.....we need to know what the data means and does not mean. Using any of the reloading information improperly is a bad deal and to be avaided.

Sure, and I may be naive, but I've always believed people like Hodgdon etc. actually tried the powders, and recorded the pressure and velosity.

Saved me buying a chrono, I thought.

Hodgdon no longer claims that H4198 gets higher velocity in 8x57 than slow powders, but there may be some holes in their data.

The LIL'GUN 357 mag 158 gr data is not what other are measuring.

But Hodgdon is very helpful and fast to respond to email. Half of life is just answering the email.

And Hodgdon data is at least not absolute crap like Speer 12 and Speer 13.