I just got a great book from A-SQUARE titled "Any Shot That You Want". What I read there in chapter "Pressure Detection by the Handloader" seems to indicate with a great number of examples that you cannot visually detect high pressure situations. They even give examples where primer pocket blowouts are the firing mechanism and not a pressure problem.

The point I get from the chapter is that in older generation firearms (early 1900s) you could visually detect pressure that is excessive, but with modern firearms it is visually impossible to BE SURE of the cause.

They advise to stick with the reloading manuals and for safety sake NEVER EXCEED the max loads. I will re-double my efforts to FEEL VERY UNCOMFORTABLE wheen I get close to the limits.

I mean, it is too late when you have a blowup in your face!!!!

Any thoughts??

yea its late when it blows up.
load data is developed mostly in lab controled enviroments with test equipement. with that each firearm you load for is designed to a standard. some of these tolerances very from mfg to mfg.
as a handloader/reloader it pays to know what the pressure signs are because in some cases I have reached max loads 2 or 3 grains under the listed load for that powder bullet case combination, in others its the oppisite.
think about it and with out some type of strain guage to tell you what pressure you reloads are working at its some what of a guessing game and from that always start low and work up. measure case webs check primers check case stretch check the web inside for thin spots ,sticky extractions hard bolt lift and Ill stick my neck out and say that the writter of that article has his head up his, well you see where im going with this.

False pressure signs can arise without excess pressure. A primer can flatten from excess head space or pierce from a burr on the striker. Cases can stick from rough chambers and safe loads.
The fact remains though whenever a pressure sign rises it`s prudent to stop and make sure you know what is causeing the problem. Gas from a primer piercing from pressure or other cause still is dangerous. Excess headspace is condition you will want to allow for in sizing your brass or preferably have corrected.

This is an area without black and white indicators.
Here is one example;

The brass you are using is not as hard as you are familiar with. You use the same components and get the same pressure signs as usual. Three or four loadings later your primer pockets are loose.
The pressure may not be excessive and it may show all normal signs but it is excessive for that brass. Over loads are not just about one shot blow ups but also about the border line loads that cause case failure slowly.

Short answer-No, you can't determine pressure by looking at a piece of brass.

Usually when you see pressure signs on a piece of brass it's already far over max pressure. There is no standard reference established for how brass behaves under pressure so it's impossible to really tell anything about pressure from looking or measuring a piece of brass. The old case head expansion method that is talked about in some old reloading manuals is a likewise unreliable attempt to expand the theory. It's slightly better than reading tea leaves to determine pressure, but not much.

Hey rje, Fortunately there are the time-tested, venerable, very best, Pressure Detection Methods ever devised - still available at low cost to any and all Reloaders smart enough to be able to read numbers. Good old, totally reliable, never fail, always works on EVERY Cartridge CHE & PRE.

Anytime you see anyone degrading those never improved upon Pressure Detection Methods, they have either performed the Methods incorrectly, have never tried them at all, or have been duped by fools.
-----

No need to ever be concerned about having one blow-up in your face " IF " you follow the instructions in the above link.

Best of luck to you.

quote:

Originally posted by Hot Core:
Hey rje, Fortunately there are the time-tested, venerable, very best, Pressure Detection Methods ever devised - still available at low cost to any and all Reloaders smart enough to be able to read numbers. Good old, totally reliable, never fail, always works on EVERY Cartridge CHE & PRE.

Anytime you see anyone degrading those never improved upon Pressure Detection Methods, they have either performed the Methods incorrectly, have never tried them at all, or have been duped by fools.
-----

No need to ever be concerned about having one blow-up in your face " IF " you follow the instructions in the above link.

Best of luck to you.

----------------------------------------------
"Serious rifles have two barrels, everything else just burns gunpowder."

quote:

Originally posted by Hot Core: Best of luck to you.

Hot Core, if I may ask, some folks say CHE & PRE only works with fresh brass due to work hardening. Have you found this to be so?

Just another question on CHE & PRE. This determines the safe working pressure for that particular lot of brass, right? Now, apart from obviously strong actions, how good an indicator is the method in unknown strength actions? i.e. Low pressure cartridge guns like the 25-20 ? I ask because I had a slight 'oopsy' with my hornet when a Winchester case got into my R-P brass. (Got picked up at the range I would think). I was not alert enough to respond to the higher level of powder in the neck (other than recharging). Well, that round gave a distinctly higher recoil (and I use the word 'recoil' loosely) and report. That case showed 'excess' pressure on the primer but there was no case stretch or any other sign of over-pressure. I am pretty sure my 'normal' pressures are close to or at SAAMI max if not a little more. (SAAMI max for my cartridge is 43000CUP revised from 47000CUP).

Good Shootin'.

At one time [ 1970's ?] Norma made brass specifically for reloaders and it has "Re" on the headstamp. Considering that reloaders don't have pressure measuring equipment they very carefully made the brass so it would show pressure signs at the maximum cartridge pressures. Good idea except that the reloaders were short on brainpower ! They either thought "Re" meant it had been reloaded or after always using over pressure loads they thought it was too soft !!

quote:

Originally posted by 303Guy:
Hot Core, if I may ask, (Q1) some folks say CHE & PRE only works with fresh brass due to work hardening. Have you found this to be so?

Hey 303Guy, A1 - This is answered in the link.

quote:

Just another question on CHE & PRE. (Q2)This determines the safe working pressure for that particular lot of brass, right?

A2 - Yes

quote:

(Q3)Now, apart from obviously strong actions, how good an indicator is the method in unknown strength actions? i.e. Low pressure cartridge guns like the 25-20?

A3 - PRE works will "ALL" Cartridges, even the Low Pressure ones, but that is also within the link, or should be. CHE does not work with "ALL" Cartridges because of their SAFE MAX Pressure is below the level required for CHE to occurr.

quote:

(Q4)I ask because I had a slight 'oopsy' with my hornet when a Winchester case got into my R-P brass. (Got picked up at the range I would think). I was not alert enough to respond to the higher level of powder in the neck (other than recharging). Well, that round gave a distinctly higher recoil (and I use the word 'recoil' loosely) and report. That case showed 'excess' pressure on the primer but there was no case stretch or any other sign of over-pressure. I am pretty sure my 'normal' pressures are close to or at SAAMI max if not a little more. (SAAMI max for my cartridge is 43000CUP revised from 47000CUP).

A4 - Neither CHE nor PRE is able to predict what will happen prior to actually firing the shot. It does work better than any other Pressure Detection Method when a normal Load Development Sequence is followed.

I would "guess" that any of the above posters who are chuckling at CHE and PRE could give you a very amusing PTBarnum equivalent answer though for Q4.

Ah... yes. I found it. Thanks Hot Core.

quote:

CHE measurements become more reliable for firings 2-5. Then CHE measurements become somewhat unreliable after 5-7 firings, depending on the strength of the previous Test Loads. This is due to "work-hardening" of the brass in the case head.

And you did say;

quote:

Yet, CHE is NOT AS RELIABLE an indicator as Pressure Ring Expansion(PRE).

And you DID say;

quote:

Neck Sizing will not reform the case wall properly for these measurements.

Of course, we are not talking of loading a case to its failure point, just keeping to factory standards. So, finding the limit of the case strength in an unkown action would be just plain silly!

Good shootin' to you!

quote:

Originally posted by 303Guy:
...Neck Sizing will not reform the case wall properly for these measurements.

Hey 303Guy, That is a Key Point of getting accurate PRE readings. The Pressure Ring must be resized between each shot in order to read how much it Expands from the normal position. This can be done with either FLR or P-FLR, but not with Neck Sizing nor using a Lee Collet Style Neck Die.

After the SAFE MAX is determined, then the Reloader can begin using Neck Sizing or the Lee Collet Dies, because there is no longer a need for measuring CHE & PRE.

Back many years ago I was attempting to get a Comparison Test done between CHE & PRE by a fellow who had a M43. We exchanged emails a few times each week and I'd phone him. I did this for right at an entire year. For some reason the PRE Data was off enough when he measured it that I could see it in what he sent me. It did not make any sense at all.

I'd been very specific about not using Neck Sizing, so I was not considering that he would actually be Neck Sizing the Cases. Finally it dawned on me that is what it had to be and the fool with the M43 finally admitted it. So, all the Comparison Testing we had been trying to accomplish for a year was worthless.

quote:

Of course, we are not talking of loading a case to its failure point, just keeping to factory standards.

That is correct. We use the Standard set by whatever Pressure the Factory Cartridges are regulated to. But, we DO NOT know what the actual Pressure is, nor do we care. We do know it is within the SAAMI Limit and that provides the margin of Safety we want.

quote:

So, finding the limit of the case strength in an unkown action would be just plain silly!

That is what our old buddy "tnekkcc" does in his Testing. But it is not something the average Reloader, nor even most experienced Reloaders should consider trying to duplicate. He works at Pressure Levels well above where I want or need to be.

Best of luck to you.

quote:

I would "guess" that any of the above posters who are chuckling at CHE and PRE could give you a very amusing PTBarnum equivalent answer though for Q4.

Yeah you ARE guessing most of the time so why not keep it up.
Much of my loading is way below SAAMI pressures. The rest of it is for cartridges that have no SAAMI standards and little or no data.

quote:

Originally posted by ireload2:

quote:

I would "guess" that any of the above posters who are chuckling at CHE and PRE could give you a very amusing PTBarnum equivalent answer though for Q4.

Yeah you ARE guessing most of the time so why not keep it up.

Oh, no. He KNOWS tarot cards and ouija boards are science, man, SCIENCE!

quote:

Originally posted by rje:
I just got a great book from A-SQUARE titled "Any Shot That You Want". What I read there in chapter "Pressure Detection by the Handloader" seems to indicate with a great number of examples that you cannot visually detect high pressure situations. They even give examples where primer pocket blowouts are the firing mechanism and not a pressure problem.

The point I get from the chapter is that in older generation firearms (early 1900s) you could visually detect pressure that is excessive, but with modern firearms it is visually impossible to BE SURE of the cause.

They advise to stick with the reloading manuals and for safety sake NEVER EXCEED the max loads. I will re-double my efforts to FEEL VERY UNCOMFORTABLE wheen I get close to the limits.

I mean, it is too late when you have a blowup in your face!!!!

Any thoughts??

With so little experience and only 8 posts, I think you had better obey the load books.

quote:

Originally posted by tnekkcc:
With so little experience and only 8 posts, I think you had better obey the load books.

Don't know what "only 8 posts" has to do with it. If an expert reloader joined up, would we laugh him off on his first post?

What case head expansion tells is that brass, with that load, in that chamber is being forced
into the yeild range. That should mean a lot to
you.
Good Luck!

quote:

The Pressure Ring must be resized between each shot in order to read how much it Expands from the normal position. This can be done with either FLR or P-FLR, but not with Neck Sizing nor using a Lee Collet Style Neck Die.

There is no problem that the resized case will have a different case head dimension than the factory case which was used to take the reference measurements? The so-called "normal position" is highly likely to be different between the first used factory round and the resized case. This alone makes the PRE process unreliable. Subsequent firings and sizings of the cases makes it more so, as the yield properties of brass change with each working.

quote:

Originally posted by JAL:

quote:

Originally posted by tnekkcc:
With so little experience and only 8 posts, I think you had better obey the load books.

Don't know what "only 8 posts" has to do with it. If an expert reloader joined up, would we laugh him off on his first post?

If he doesn't want something to blow up in his face, what motivation do I have to help him overcome his fears?

There are lots of people who are innovative hand loaders from the first day, but most never get past load books in a lifetime.

It is not laughing them off to let people be on their own level.

jackfish, this whole thing is very confusing. I asked the same question only to find it has been answered! It is all beginning to make sense now. So here it is again. This is from Hot Core

quote:

CHE measurements become more reliable for firings 2-5. Then CHE measurements become somewhat unreliable after 5-7 firings, depending on the strength of the previous Test Loads. This is due to "work-hardening" of the brass in the case head.

Well, I CAN certainly tell when the pressure is high enough to ruin a case! By that time, however, safe pressures have been left far behind!

I'd say no, except when brass is flowing into the exactor cut, pressure is too high. It is also too high if you find a primer in the magazine when you open the bolt. Other than that, appearance of a case is a poor indicator of pressure.

CHE and PRE are reliable only when using unfired cases. This has been proven over and over by many including myself. The problem with CHE is that you are alredy in high pressures before you get a measurement. CHE is not a reliable method to use unless you have an action that can stand a diet of proof level pressures.

PRE on the other hand can be used (if done the correct way) to duplicate a known safe load (factory) with your own componants excepting the case.

Larry Gibson

quote:

originally posted by hotcore: ...still available at low cost to any and all Reloaders smart enough to be able to read numbers.

quote:

Originally posted by tnekkcc: ...With so little experience and only 8 posts, I think you had better obey the load books.

that sums it all up right there: those two proponents think they are smarter than everybody else, including professional reloading ballisticians, and they have an authority complex.

quote:

Originally posted by JAL: Don't know what "only 8 posts" has to do with it. If an expert reloader joined up, would we laugh him off on his first post?

depends. were he an advanced reloader, willing to face his fears and thus overcome the need to obey those so-called "reloading manuals" then no; hot core and tneckk would not laugh. and then there would be three....

however, were it any other ignoramus unwilling to drink to che/pre-flavored kool-aid, such as a Ph.D who sells well-regarded ballistic equipment, then the answer is: YES they would laugh. the same way they laugh at the silly fools who work in reloading and ballistics labs; the way they laugh at the unwitting dolts who make, test, and sell components; the way the laugh at all of us who listen to people trained and educated in the complex science of ballistics.

quote:

Originally posted by rje:
I just got a great book from A-SQUARE titled "Any Shot That You Want". What I read there in chapter "Pressure Detection by the Handloader" seems to indicate with a great number of examples that you cannot visually detect high pressure situations. They even give examples where primer pocket blowouts are the firing mechanism and not a pressure problem.

The point I get from the chapter is that in older generation firearms (early 1900s) you could visually detect pressure that is excessive, but with modern firearms it is visually impossible to BE SURE of the cause.

They advise to stick with the reloading manuals and for safety sake NEVER EXCEED the max loads. I will re-double my efforts to FEEL VERY UNCOMFORTABLE wheen I get close to the limits.

I mean, it is too late when you have a blowup in your face!!!!

Any thoughts??

OK. I still can't see anything wrong here, but I am particularly obtuse today. He does say "wheen I get CLOSE to the limits".
One possible misinterpretation of the book might be the difference between pieced primers from "the firing mechanism" and primers dislodged from the primer pocket due to excess pressure.
While I don't laugh at any experts or reloading manuals, some of the differences are amazing. . . not amusing.

So where I have sometimes snuck gradually over some manuals max, others I've backed off smartly, and one I saw a few days ago I won't even attempt to get close to. Nearly 2gr over the powder manafactures max which includes a 50K.cup.reading, all in a little .223Rem case.

Don't want to insult anyone, but for various reasons I don't use any pressure or velosity methods stated here, I'll put up with some primer flattening, but if pockets expand too quick I start working backwards, and any so called pressure signs on brass, ONE shot was enough thanks, out comes the bullet puller.
If that leaves power/range/knockdown short, good excuse to buy a bigger cal.

While many here would call me a bit cautious, I never run over what the book says. But the maddening thing is that different books say different things. (I mean later editions of the same bullet maker).

Being a son of Nebraska, I mainly use Hornady bullets. Loading up some .300 Savage for my father in law, I had a very nervous moment when I found the newest edition of the manuel had the top end load 2 grains lower than the previous! So I pulled all the ammo (it was a 20 round ladder work up group) and started over.

The other funny thing is that as many here have said, you can get flat primers for a lot of reasons besides pressure. A friends .25-06 has flat primers with factory ammo! Scared the heck out of me on a varmit hunt, till he had a gunsmith take a real close look at it.

quote:

A friends .25-06 has flat primers with factory ammo!

During nearly 4 decades of scrounging once fired brass I have found factory ammo with blown primers in two calibers in particular. One is the 6MM Remington with Remington ammo, the other is 25-06 with Remington ammo. There round are loaded hot form the factory. I also found a blown case in Norma 7X57 ammo. In the case of the Norma I suspect the Norma case was bad (too soft) rather than the load being to high a pressure.
A benefit of using once fired brass is the cases have already been "proof fired" for defects.

quote:

Originally posted by NEJack:
A friends .25-06 has flat primers with factory ammo! Scared the heck out of me on a varmit hunt,

I've learnt from AR members Stonecreek originally, that the loose headspace on factory rounds will make primers flat even though pressures may be normal.