Traditional Pressure Indicators and Magazine Writers

[Graybeard]

Just finished reading an article by John Barness in Handloader Magazine. John has now become the third big name rag writer to come out openly and say that all traditional pressure indicators we've been using for many many years are flawed and just plain do not work.

He was about as clear and concise in condeming their use as any. The first was Rick Jamison several years ago. Since reading that one I've been trying to get the message out here on the internet. Rick was quite clear in his message. They just plain do not work. At best they are unreliable and at worst down right dangerous. John pretty much said the same.

The second writer I noticed say it was Craig Boddington. (Note no title like he wishes to be known by. He's never been a favorite of mine but when he felt the need for a title he dropped way down there.) He was less specific than the other two but still made it clear his tests show that none of the traditional pressure indicators are safe to use in determining what load is OK or not OK in your rifle.

So how do you know what's safe minus your own pressure testing equipment? Quite honestly you don't. BUT if you stick to pressure tested loads in major reloading manuals and DO NOT EXCEED their maximum listed loads you're on reasonably safe ground. Better yet is having a variety of manuals and comparing them. If one is listing loads well above the others then I'd be real leery of them.

Sorry guys but starting low and working up while watching for TRADITIONAL PRESSURE INDICATORS just don't cut it. Even the major mag writers are finally coming around and admitting it.

So why might those max listed loads (or even some below max listed) be unsafe in your rifle even tho safe in the pressure testing?

1. You might not use precisely the same brand of components they did. Any deviation will change pressure. Might change it up or down.

2. Your lots of power, primers, cases and bullets EVEN if same brand will be from different lots than they used. Any different lot will change pressure some. Might go up or it might go down.

3. Your chamber will differ from theirs. No way to predict the effect this will have on pressure. Might go up or down.

4. Your barrel is different than theirs. Again it will change pressure and no way to known if up or down.

5. Just too many variables between your loads and your rifle and those used to work up the loads. Might be the different variables will cancel each other out and all will be fine. Might be they will all add up to less pressure. BUT it might be they will all add up to way MORE PRESSURE and be dangerous even tho tested safe by the manual maker.

Bottom line is that it's quite foolish to accept non pressure tested loads as safe just because someone says they are. It's not even certain that pressure tested loads near their listed maximums will be safe in your firearm. If you change any component from those listed this is even more true.

OK fire away all you arm chair experts. Tell us how it's really OK to go ten grains over the max cuz them folks really don't know what they are doing when they do the pressure testing. Of course don't feel too bad when I dump the post if you do.

[Reed1911]

As so often is the case, the rag writers are coming out and contradicting themselves again. While I find most of the magazines interesting, it is more along the lines of entertainment and not academic study. Many do give us interesting ideas and a general area the begin investigation, but all of their words need to be taken with a pound of salt (not just a grain).

Take for instance the articles of what makes a good (place you game here) gun or how the newest gadget will make you shoot better. The best gun for "X" game is one that you can shoot well, practice with a lot, and will kill the animal an honest and sportman-like way. Yes I do realize you can kill a deer with a .17 Remington, but I likely cannot. Gadgets are great, when used as intended with practice; like a very accurate firearm, it will make a good shooter better but a bad shooter will still be a bad shooter (with nothing more than a lightened wallet).

On the subject of pressure, the idea of traditional pressure signs is correct, but only to a point. When those signs present them self, usually you have gone WAY beyond the set pressure limits. So yes at that point you are over pressure, but your were over pressure a long time ago. Thankfully technology comes along, grows, and prices reduce swiftly. I'm sure it will not be long that pressure testing equipment will be as common as chronographs and digital scales.

[ButlerFord45]

Far too many reasons for flat primers, difficult extraction, split cases that have nothing to do with excessive pressures.  Check the manuals (numerous) and compare then stay within published parameters.  If that is not fast enough to keep you happy, it's time for another calibre.

[Questor]

Well put, GB. I am amazed at how often even some of the writers you mentioned by name will say that they had a load that was "a bit warm" , or words to that effect, to describe situations in which a load was so hot that the case fused to the bolt face and locked the bolt shut. It sets a bad expectation and makes a bad example.  

We have today the works of many competent ballistics engineers from companies like Speer, Hornady, Nosler, and others. Their companies ask a relatively small fee for the data they provide in their load books. All we need to do is follow their recipes and the likelihood of problems is very low.

[R.W.Dale]

Use your chronograph!! If a published load is only supposed to have a velocity of 2800 FPS and you're getting 2950 there is something funky going on inside that case thats needs your attention.


 Now more importantly are our old reloading manuals say 15+ years old dangerous to use??? Aftre all they advocate using these warning signs to "Read high pressuer signs" ?

[Graybeard]

YES. To a very large extent those old manuals are dangerous to use. For many reasons other than just the fact they were not properly pressure tested. Powders change with time even if the name stays the same. Loads that were once safe aren't always now. But back then no pressure testing was done for the most part. They used the now well known unreliable "pressure indicators" and many of them are in fact enough to in time wreck modern guns.

John did go on to discuss the use of a Chrono under a very specific set of circumstances as the best we loaders without pressure equipment can get. BUT within very narrowly defined parameters. What he mentioned in it's use is pretty much what I've been doing for a few years.

[High Brass]

Butler Ford wrote:

"If that is not fast enough to keep you happy, it's time for another calibre."


I was beginning to think that I was the only one that thought this way!

[Castaway]

Maybe it's my imagination or a dose of Old Timers disease, but if I remember right, there was a Handloader a year or two back that had two conflicitng articles.  One that said you couldn't measure and compare factory ammo with pre and post-fired brass to determine operating pressure and and another article which went into detail on how to do it.  That did it for me.  Since then, I'm even more convinced to err on the safe side of caution.

[Haywire Haywood]

I'm by no means an expert, but when I was asking questions and learning the do's and don'ts of reloading, I was told to work up a load with a chronograph and stop when you reach book max on powder weight or the velocity given for that powder weight whichever came first.  That's basically what I've been doing.

Safe practice?  I dunno.  I've still got all my fingers and toes, and haven't violently disassembled any of my firearms as of yet.   :eek:

Ian

[Greybeard]

If you will look at the article in Handloader by Barness (BTW an excellent article) you'll see why that practice isn't by any means fool proof. The use of different brand primers when tested by many different sources that I've seen the data from indicate that they have a far greater effect on pressure than on velocity.

In the article Barness used a chart from a study done by someone else, forget who at the moment, that showed huge pressure differences with very small velocity differences.

So if you're using one of the primers that raise pressures way up there you can easily be way over safe pressure limits and yet velocity still be about what the book shows.

Now if you're using ALL components EXACTLY like the book recipe except your lots are different you have a good chance of being safe when the velocity reaches what the book says. This is basically what I've been doing a long time. I use primers from the milder pressure list only. Never those on the hotter or higher pressure side of the list. I just do this as a matter of course for safety's sake.

[Haywire Haywood]

I don't have access to that article..  Maybe you can reference it for me.  I use CCI primers almost exclusively.  Federal LR Mag for 45-90 BP loads.  Where do they fall in the pressure range?

thanks,
Ian

[Lone Star]

I've been called everything but a knowledgeable man on this and other sites whenever I comment that we should not use old loading data, and that exceeding modern published maximums is potentially dangerous.  The first time I personally had a wake-up call on this topic was when I read an ST piece written by Jameson at least five years ago - whenever it was he first got his own Oehler 43 and discovered that many loads he'd been using for years were over the SAAMI maximum pressures, some by a lot.  At that time I re-evaluated my own load development regimen and made some changes.   :roll:

That extra 100 fps we get means nothing in practical terms, but it may make the difference between high and excessive pressures.  Those who wait until they get heavy bolt lift before they stop adding more powder are playing with fire, IMO.  We get away with it because modern rifle and handgun manufacturers build a llarge safety factor into their products.  We are foolhardy using these loads in old military rifles 75+ years old, yet many do.  How many of these guys set back the bolt lugs or lug recesses on their rifles, we'll never know.   :shock:

Is it any wonder that most of these makers disallow the use of handloads in their products?    :oops:  :oh:

[Haywire Haywood]

Just for the sake of arguement, suppose I have a favorite handload, been using it for 25 years, loaded hundreds of them, taken dozens of animals with them.  I then acquire a new piece of equipment that tells me I my favorite load is way over SAAMI max pressure.  

Does that tell me I've been skating on thin ice for 25 years and been extremely lucky or that SAAMI has lawyer resistant pressure standards?

Ian

[Lone Star]

SAMMI standards are engineering standards to insure that all guns and ammo produced by SAAMI members will interchange safely.  The firearms manufacturers build a safety factor into all their firearms, but that is if everything works as planned.  Unfortunately, if a case - the weakest part of the entire firearms system but the one we compromise the most - fails, then high pressure gas will be vented out of the firerarm.  Maybe all that will happen is a damaged firearm.  Maybe you'll lose an eye or worse.  

It's kinda like speeding - your car can safely go 120 mph - or faster - but if you hit something or have a blow out at that speed...... :twisted:

As someone who has been involved in personnel safety in one of the most dangerous industries, I take safety very seriously.  I've seen far too many lost extremeties, etc.  for one lifetime.

[Haywire Haywood]

It's kinda like speeding

I like that analogy, it's not that the equipment won't do it, but that the damage involved if something does give way increases beyond acceptable limits if you do.  "Risk Management" I think it's called.

Ian

[longwinters]

Ok, a lot of this makes sense.  But I have an article by John Barsness (down in the basement) where Barsness tells of his best loads for specific calibers that work day in and day out in a variety of rifles.  Of the ones I have looked at, all of them go over the max loads given in most of my reloading books.  Some by 3 grains.  Examples would be for the 280 and 7m-08.  For the more common 7m-08 he says that for a 139-140 bullet 47-50 grains of H4350.  47 grains is over the max in my books. . . let alone 50 grains. He then says  Maybe a little less for a "sticky" bullet.  How does all of this fit with his article, which I have read, on over pressure?  As well as, I think, good comments made here on staying within the reloading book pressures?

Long

[Lone Star]

For the more common 7m-08 he says that for a 139-140 bullet 47-50 grains of H4350.  47 grains is over the max in my books. . . .

You obviously don't have enough books.  In the Hodgdon 2004 Annual Manual, they list a max load for the 139-grain Hornady at 50.0 grains of H4350.  Looks to me like the writer doesn't contradict himself at all, particularly as he lists a range of charge weights.  

[PaulS]

There have been many studies - one at least by the NRA and published in the American Rifleman that shows that in strong modern bolt action guns micro cracks begin to weaken the chamber walls long before any catastrophic failure occurs. Using a gun and its loads from a reloader who admittedly loaded hot. They pressure tested the loads and found they were an average of 23% above SAAMI but showed none of the signs of over-pressure that we have all been trained to look for. They etched and examined the rifle and found minute cracks lengthwise throughout the chamber area. The rifle was well on its way to failure but had never been stressed to the point that it would just rupture.
The reason acceptable pressure limits are requiring less powder than they used to is partly the formulation of new powders (even by the same designation) and the more precise measurements we can take today.

We have ways to test for chamber pressure just like the labs today but we don't have the Test loads to calibrate our equipment. The best way that we can calibrate our test equipment is to use factory loadings and make sure that our loads do not exceed those by more than 2%.

If you need more out of your cartridge than that will get you then you need a different cartridge.
PaulS

[Slamfire]

Before I got a chronograph I loaded by expansion ring measurement figuring what the factory could do would work for me too. My experience with that method told me I was reaching factory expansion at LOWER pressures than brand new factory loads.
Then I started with the low charge and increased by  1 grain at a time until the velocity didn't match the preceding increases, and backed off 2 grains. I've found maximum book loads to be too hot in one of my rifles, and the Lyman book went well beyond that point.
The pressure equipment most likely to be used by handloaders also works in relative pressures instead of absolutes. I think that it takes at least two hundred extra fps to give me 25 yards better range, so tend to stay low.
The destructive testing by PO Ackley showed most rifles could be seriously damaged by gas getting into the action. The Japanese Arisakas were measurably stronger than any others tested. Too bad they are so crudely made, as far as smoothness of action.   :eek:

[handirifle]

OK
I'll bite.  Let me play devils advocate here without anyone getting their panties in a wad please.

Things do change, powders, pimers, cases etc and so do writers numbers.  I read an article a few months ago, by Rick Jamison, I think it is in the 2004 Hodgdons annual manual.  He goes through the motions of showing how using the case head expansion is the "new deal" for pressure testing.  The problem I have with his article is he is trying to prove the max load in the manual is the max pressure load.  But when I re-read the article I noticed his math is flawed and the load is OVER published book before he hits the desired case expansion max.

Remember here, I am not saying all you guys have said is wrong, just pointing out some flaws with the "new" system as well.

Next we say SAAMI is the god of reloading pressure limits.  If that is the case, then 90% of the 45-70 loads out there are unsafe.  SAAMI lists those loads (although manuals DO break them down now for different typre firearms) well below what modern firearms are capable of.

Next is the 280 Rem.  Someone please explain to me why it is loaded (I'm talking handloads now, not factory) to lower pressures than the 270, when they are basically the same round, used in the same rifles.  The exception is what the 280 was ORIGINALLY designed to be fired in (an autoloader).  Isn't this about the same thing as the 45-70?

There, that ought to stir it up a bit :grin:   remember, play nice.  read my first sentence again BEFORE commenting!

[PaulS]

handirifle,
Play as you like. SAAMI is not a reloaders god - they simply apply regulations to those rounds submitted by the industry manufacturers. The SAAMI specs apply to rounds as originally developed in the original type of firearms. Can I safely boost the pressure of a 45-70 if I load it into a bolt action custom gun that is designed to take 200000 psi? Sure I can but SAAMI isn't going to change their standard unless I replace all the guns out there with mine and I can prove to them that there are no other guns that will fail at pressures lower than mine.
By the way, if you try to sue SAAMI for a rifle that blows up in your face you won't get far. You will have better luck proving the rifle was bad or the ammo was loaded improperly at the factory than saying the the pressure standard was too high it your gun failed at a SAAMI recommended pressure. I don't think they have lawyers on staff for lawsuits - just to keep the manufacturers in line.
PaulS

[handirifle]

Well that was totally unexpected.  First I never expected SAAMI to change.  Second, it makes perfect sense why they do what they do.  


Who said anything about suing anyone???

All I was saying is the "books" are meant for SAAMI specs loads and some of these are no longer what they were originally.  The 280 and 45-70 are perfect examples of this.

Jamisin's own article on reading pressure signs is full of mistakes.  He shows the "normal" pressure signs well before the case head expansion comes into play, yet he totally screws up his math to prove the case head thoery works.

I'm not going to sit here and try to second guess the factories and the industry's new standard, just pointing out that there are many flaws in the way people are explaining the reasons for the sudden change of reading "true" pressure signs.

Are they better equipped to read pressures than me?  Yes of course.  I keep referring to the Hodgdons manual with the 375 Win loads.  In the hardback version (not in front of me so I cannt remember the manual number) the published max load for the 375 Win with 200gr loads is nearly 400 (yes that's 400) fps slower than what is listed in their own annual manual.  When I finally got a Hodgdons rep to talk to me he said the hardback speeds were fron measuring the case head expansion, and the annual manual were from an actual pressure reading from a pressure barrel?

Now is the case head expansion the new say so on "true" pressure?

By the way, SAAMI was created to make manufacturing consistant form maker to maker, things like chambers cartridge dimensions, etc.

I still don't get where the suing came from?

The way I read it is similar to eggs.  They were good for you, then they were bad for you, now they're good for you again.  All this from "factual" scientific research.

I'm not suggesting anyone overload any case for any gun, just saying don't be so quick to jump on the new and improved bandwagon so quickly.  I don't think even they have it all worked out just yet.

[Lone Star]

I get a kick out of the reloading "experts" who, with a couple of decades of experience loading for a dozen cartridges, decide they are far more knowledgeable than the professionals on pressures and safety.  Some are convinced that there is a conspiracy among loading manuals and SAAMI to hold down the performance of their rifles - I can only suppose the reasons must relate to big givernment, communists, and Halliburton.   I suppose this is all rooted in a basic mistrust of science fostered by a few radical secular and religious pundits.  They seem to forget that it was not a group of good old boys with grease under their nails working off napkin drawings in a garage who designed and built the space shuttle, the Saturn V, the FA-18 or the celular phone system...

Eggs - like many other of the supposedly "scientific" studies we read about, these are funded by "interested parties".  The results are like the many "polls" we read each week - the study is only as good as the vested interests who fund it allow it to be.  The government funds a study saying eggs are "bdad", then surprise, the egg industry funds one which refutes it.  These examples are hardly the same as what we are discussing here, where writers with little to no technical background try to pass themselves off as pressure experts.  Not.

BTW the .280 was designed for Remington's M740 semiauto rifle; at the time Remington found that they needed to reduce the chamber pressure to improve function with the .280.  Later bolt rifles don't need the pressure reduction, but because of all the old M740s out there, the published pressures remain the same.

Measuring case head expansion to guess at chamber pressures is hardly "new" - it is at least 50 years old.  It has also been amply demonstrated that it can give very erroneous results.  The bottom line, regardless of what Jameson says in one or the other article, is that we as reloaders have no fool-proof method of determining the safety of our reloads if we stray from published loads - and even then we can get into trouble!  The Oehler 43 is a great tool, and I was luck enough to use one for awhile, but as stated it is a relative measureing system.  Reloading truely is what they tell us it is - a use-at-your-own-risk passtime.

[handirifle]

OK no need to get nasty.  First off, re-read the first line of my first post!

I have never called myself an expert in reloading, and never will.  I have 30 years of loading about 6 different rounds so I don't even come close.  I'm mearly asking the obvious questions here that are an apparant contridiction to what all was being said here.

The way I phrased the comment on the 280 may have left you to believe I didn't know this but I did.  What I wonder is why not put different load levels in for it just like they do for the 45-70?  Without that, people will never take it past the power level it was created for and PAST the 270 where it belongs.

As for a conspiracy, someone's been watching too many movies.  Have you NEVER questioned a rule, law, guideline, or something that some "offocial" has stated as "fact"?  I seem to remember reading about a Spaniard that was told he's sail off the end of the earth if he went to far.  That was a know fact at the time.  Instead, here we are because he believed otherwise.  I simply said there are flaws in their system.  You need to completely read my post with both eyes open.  I have never claimed to know more than they.  Nor will I try excessively hot loads to prove them wrong, but neither will I always sit and listen to the "rules" be contradicted all the time by the industries own experts and never question their methods or results.

If anyone answers for the questions I have raised please speak up without deflamitory comments.  The questions were raised, as I mentioned earlier, by conversations with the "experts" in the industry, not just off the clear blue.  I don't care if the head expansion IS 50 years old, even Hodgdons admitted to me that the method was flawed in their own findings.  A 400fps difference is HUGE!  Remember it was a 400fps gain when reading from loads using TRUE pressures, not from measuring the case.

[Graybeard]

I suspect the mentioned case head expansion article by Jamison was written a long time ago and just still being used by the manual. Cuz Jamison was the first of the major writers to come out and say it and other traditional pressure guessing methods didn't work in the real work when compared to pressure measuring equipment.

[Black Jaque Janaviac]

Wait a minute Greybeard.  It sounds like you're saying reloading isn't safe at all unless you have pressure testing equipment.

At first you say to stay within published data.  Which is the standard advice.  But then you tell us that the published maximums are not safe.  And that watching for pressure signs as you approach maximum charge is no good either.

So the only way to be sure that your load is below SAAMI specs is to exactly duplicate the load, right down to the precise lot number of the components.  :roll:   But what is safe?  To be sure that your load is under SAAMI specs?  Or to be sure that your load won't blow up your gun?

How often does it happen that a published max load actually ruins a gun or injures a shooter?  In other words, of people using the traditional method of start 10% below max, work up to max watching for pressure signs, how often does something fail?

[Graybeard]

Wait a minute Greybeard. It sounds like you're saying reloading isn't safe at all unless you have pressure testing equipment.

Dunno what you're reading but I don't think it's anything I wrote. I made no such statement. Altho that would be the ONLY way to KNOW what pressure you are getting with your ammo in your gun.

At first you say to stay within published data. Which is the standard advice. But then you tell us that the published maximums are not safe. And that watching for pressure signs as you approach maximum charge is no good either.

What I said was some of the published maximums in old manuals from before pressure tested data are clearly over SAAMI pressures. IF you accept SAAMI as the max safe limits then yeah those would be unsafe.

So the only way to be sure that your load is below SAAMI specs is to exactly duplicate the load, right down to the precise lot number of the components.  But what is safe? To be sure that your load is under SAAMI specs? Or to be sure that your load won't blow up your gun?

There is actually no way to be 100% certain except to do pressure measuring of your loads in your gun. But if you use the book recipes you shouldn't harm the gun or yourself. Deviate too far and all bets are off.

How often does it happen that a published max load actually ruins a gun or injures a shooter? In other words, of people using the traditional method of start 10% below max, work up to max watching for pressure signs, how often does something fail?

I have no clue. Not very often I'd suspect. But that's not to say that a stack up of tolerances never causes it. But would be rare and likely only in a gun that's already been over stressed by over pressure loads.

All I have really said is old data from before pressure testing by manual makers might be unsafe. Data from any source internet or otherwise is suspect unless provided by a manual maker or powder/bullet maker who tested them in pressure equipment. Substituting other brands for book recipes means you are NOT following the book recipe. Using different lots as you will be can in very rare instances mean max book loads are too hot in your gun.

Will it blow? Likely not. Will I promise you it won't? Nope.

[Black Jaque Janaviac]

Graybeard,

Ok, here's what I read:

 

BUT if you stick to pressure tested loads in major reloading manuals and DO NOT EXCEED their maximum listed loads you're on reasonably safe ground.

Then one paragraph later:

Sorry guys but starting low and working up while watching for TRADITIONAL PRESSURE INDICATORS just don't cut it.

followed by:

So why might those max listed loads (or even some below max listed) be unsafe in your rifle even tho safe in the pressure testing?

I added the italics.

This last sentence suggests that even the pressure tested data of the newer manuals is not necessarily safe.

I'm not picking on ya.  I'm just not getting your signal clearly.  And since I respect your opinion, I am seeking some clarification.

[handirifle]

What I said was some of the published maximums in old manuals from before pressure tested data are clearly over SAAMI pressures. IF you accept SAAMI as the max safe limits then yeah those would be unsafe.

Actually, it was the other way around.  The older hardback manual's loads were nearly 400fps BELOW the 2004 published loads from Hodgdons own annual manual.

The older case head expansion method left us with a load well below the ACTUAL pressure limit of the case.  The article that Jamison was published in the SMAE manual, the 2004 Hodgdons annual manual and had he done his math correctly, it would have shown the case head expansion didn't occur until he was well above published loads.

So, in one case the head expanded well below published loads and in another it expanded well below.  But both of these experts stand by the same method.

See, sometimes we NEED to question the experts to keep them straight.  I still think their methods are flawed.  Do I know more than they and am I going to throw my books away?  No, but I'd be willing to bet thousands of rounds have gone downrange safely by the "old" methods, and will continue to do in the future.

This, to me, is like the 300 Win Mag vs. the 30-06 argument.  Sure the new kid is faster, stronger, better, but the old kid still gets the job done.

See what playing the devils advocate does?  Sometimes we need to see something from more than one viewpoint.

My ideas on reloading are read the books, read the rules, know the consequences of breaking rules and act accordingly.

Oh, and as for the eggs, who on this forum doesn't think that there is something for the reloading companies (powder, bullet manufacturers etc) to gain by telling us the old manuals/methods are not safe and that the newer, faster, stronger manuals are better and safer?  conspiracy?  No just business.

If I make vacuum cleaners and sell them do you think I want you to ignore my newer "improved" model?  No vacuums are not explosives and most likely they won't kill you, but when was the last time someone's gun EVER blew up or anything even close using published data from an old manual?

I bet anyone would be hard pressed to find a single example, where the gun was not ALREADY proven defective.

Load safe, read the manuals and READ the pressure signs.

Ya'all enjoy!   I have!

[Graybeard]

Wow this thread really seems headed down hill fast. Folks you're looking for what's not there.

Read carefully what I said. Try to find the orignal articles I mentioned. Do some serious research.

It's a fact that unless you have pressure meansuring equipment and use it to measure the loads you put together using your components in your firearms and compare it to known standards you really are just guessing at what pressures you're getting. It WILL NOT be the same as the book data pressure tested results. Might be higher. Might be lower. But it won't be the same.

That's about all I've really been trying to get across.