I brought a 1000 rds of 8mm surplus turned out to be loaded with a 198 gr fmj with 44grs of flake powder. I only shot 10 rds or so and noticed stiff bolt lift on each one.

I decided to not shoot the stuff any more. It sat around the loading room for a couple of years. I finily decided to too something with it.
I pulled some bullets dropped the powder charge 4 grs. Now I get 2220 fps no sticky bolt lift.

Well be a useful paractice load without damageing the gun.

A lot of 8 mm surplus ammo shooters think the ammo is "over pressure" because of the "sticky bolt". This opinion is most often reflected with shooters of Turk ammo but also with some of other make. I have run numerous tests with various ammo of this type and found it is not over pressure. What happens is the annealing process of the cases was not adequate and the cases have become brittle. Note most all the necks of Turk ammo have not been annealed at all. What happens is when the cartridge is fired the case expands (many split at the neck/shoulder when fired or when the bullet is pulled) but since the case is brittle it lacks the elasticity to spring back. Thus the bolt lift is "sticky".

A simple test for yourself is to load the powder charge and bullet into commercial Rem/Win cases and fire them. If you do you will find the bolt lifts normaly. Keep in mind that most all surplus 8mm are "full" power loads but they are not "over pressure".

BTW; I also pull a lot of 8mm and reduce the powder charge5% just to get around the sticky bolt. It does make for pleasant practice ammo.

Larry Gibson

What is your bore size?? .318" or .323"?? What diameter bullet are you shooting - probably .323"...

- mike

quote:

Originally posted by Larry Gibson:
What happens is when the cartridge is fired the case expands (many split at the neck/shoulder when fired or when the bullet is pulled) but since the case is brittle it lacks the elasticity to spring back. Thus the bolt lift is "sticky".

Not to say you are wrong but I have a hard time buying into that analogy. I'm also not sure what over pressure means in this case. ( double ontondra I guess). It would be handy if someone out in the either has great EVIDENCE. roger

A hard opening bolt to me after firing a round to me tells me the round is creating to much pressure.

Weather it is bad brass or to much powder its a pain in the butt to have yank on the bolt to get it open. I'll gladly pull them and use the lower charge to be safe.

the rifle is a 98 with a 323 bore and 323 bullets.

I've got around 2500 rds of the surplus Turk ammo. Random sampling (shooting) of the stuff tells me it is quite a bit "hotter" than some of the other non Turk surplus I have. I use a 24/47, a steel buttplate, and my shoulder as a pressure gauge.

I have a case of circa 1944 Ecuadoran 8mm Mauser.

I'm shooting in a 38/22 and a M-48 Yugo. Chrono reading are high, but I've never had a sticky bolt or any other classic "pressure index."

Friend of mine shoots this ammo in a Turk with no problems.

I'm inclined to go with the "stiff brass case" theorum.

quote:

Originally posted by bartsche:

quote:

Originally posted by Larry Gibson:
What happens is when the cartridge is fired the case expands (many split at the neck/shoulder when fired or when the bullet is pulled) but since the case is brittle it lacks the elasticity to spring back. Thus the bolt lift is "sticky".

Not to say you are wrong but I have a hard time buying into that analogy. I'm also not sure what over pressure means in this case. ( double ontondra I guess). It would be handy if someone out in the either has great EVIDENCE. roger

Not an "analogy", it is what happens.

Larry Gibson

I know one thing the Turk ammo I had split almost every neck but caused no damage or sticky bolt. But it did beat my shoulder. Sure was cheap enough but after a couple bandoliers of it I sold the rest of the case. Now all I shoot out of my 98/22 is reduced handloads and they are a pleasure to shoot.

I agree with Mr. Gibson. Turk ammunition (brass) lacks the quality of other surplus 8m/m Mauser ammunition.

quote:

Originally posted by p dog shooter:
A hard opening bolt to me after firing a round to me tells me the round is creating to much pressure.

Weather it is bad brass or to much powder its a pain in the butt to have yank on the bolt to get it open. I'll gladly pull them and use the lower charge to be safe.

the rifle is a 98 with a 323 bore and 323 bullets.

roger

Analogy? Analogy? We don't need no stinking ANALOGY!

quote:

Originally posted by bartsche:
Not to say you are wrong but (...) It would be handy if someone out in the either has great EVIDENCE.

Well, I have no problem in saying that Larry is wrong. And I also have no problem in presenting the clear, clean evidence for which you asked:

http://www.turkmauser.com/ammo/mhbTurk.aspx

Velocity measurements. That's (secondary) evidence; not "feelings" of a reluctant bolt. Primary pressure measurements would be better, but they are notoriously difficult to get in the USA.

Carcano

quote:

Originally posted by p dog shooter:
A hard opening bolt to me after firing a round to me tells me the round is creating to much pressure.

Weather it is bad brass or to much powder its a pain in the butt to have yank on the bolt to get it open. I'll gladly pull them and use the lower charge to be safe.

the rifle is a 98 with a 323 bore and 323 bullets.

Just out of curiousity, did you chrono the original loads? If so, what was the MV before you reduced the charge? My uncderstanding is that the heavy ball load was rated at around 2400 FPS.....

quote:

Originally posted by carcano91:

quote:

Originally posted by bartsche:
Not to say you are wrong but (...) It would be handy if someone out in the either has great EVIDENCE.

Well, I have no problem in saying that Larry is wrong. And I also have no problem in presenting the clear, clean evidence for which you asked:Carcano

You da man Carcano! roger

quote:

Originally posted by carcano91:

Velocity measurements. That's (secondary) evidence; not "feelings" of a reluctant bolt. Primary pressure measurements would be better, but they are notoriously difficult to get in the USA.

Carcano

Not so "natoriously difficult" anymore.

Well a .308W at 60-62,000 psi doesn't have hard bolt lift in a M98. A .270W at 62,000 psi doesn't have hard bolt lift ina M98. Magnum cartridges that operate at 62-65,000 psi don't exhibit hard bolt lift in a M98. So then we must ask ourselves if we get the hard bolt lift with 8x57 Turke ammo in a M98 is it because the psi exceeds that of these other cartridges?

Just so happens that I ran tests on 4 different lots of Turk ammo ('42-51) today with an Oehler M43. This intrument gives pressure readings via a strain gauge. I also ran tests on 2 different factory loading and those pressures were right where they were supposed to be. Testing was done with a Yugo 24/47 in excellent condition. Appeared to be an arsenal rebuild (new) when I got it some years back. Headspace is very tight.

The average peak preassure (M43) and velocity of the 4 lots of Turk ammo were; 61,300 psi/2876 fps, 61,800 psi/2849 fps, 58,700 psi/2873 fps and 53,700 psi/2775 fps. Even the lot with 53,00 psi still gave the same "sticky bolt" opening as the higher pressure loads. I'll stick with my original "analogy" that the cases stick because the brass cases are brittle. That is why the case bodies split and the necks crack as evidenced in the site you posted.

Larry Gibson

As I said before, I agree with Mr. Gibson.

quote:

Originally posted by buckshot:
As I said before, I agree with Mr. Gibson.

uhh-OK roger

I have no equipment to measure pressures or velocities but I had a number of problems both with Turkish as well as with Greek Olympic 8x57 ammunition, both of which made my rifle very difficult to open. However, the worst jamming of the bolt that occured was with a Sellier and Bellot round which jammed my rifle's bolt so tight that I had to get a mallet and hammer it open.

My rifle is a "new" one custom made by a member here with a new barrel on a military Mauser action with folding leaf sights. I doubt that J and S bore diameters have anything to do with the problems though, of course, I am happy to accept that I am no expert.

quote:

A simple test for yourself is to load the powder charge and bullet into commercial Rem/Win cases and fire them. If you do you will find the bolt lifts normaly.

This test could be determined viable if the commercial cases have the same internal capacity as the military cases, but if commercial are larger capacity ,pressures would be lower. I think a better test would be to dismantle several military cases, properly anneal them and fire. Larry could you get on this and get back to us? It's hard to break OLD habits, if it's sticky-it's too hot, but then I don't have a Kenny O WB43xpmaziwiz-bang PB lab.

quote:

Originally posted by swheeler:

quote:

A simple test for yourself is to load the powder charge and bullet into commercial Rem/Win cases and fire them. If you do you will find the bolt lifts normaly.

This test could be determined viable if the commercial cases have the same internal capacity as the military cases, but if commercial are larger capacity ,pressures would be lower. I think a better test would be to dismantle several military cases, properly anneal them and fire. Larry could you get on this and get back to us? It's hard to break OLD habits, if it's sticky-it's too hot, but then I don't have a Kenny O WB43xpmaziwiz-bang PB lab.

Already done; used a lot of 1943 Turk loaded with steel strippers that gave the 61,800 psi at 2849 fps. I pulled the bullets and loaded them and the powder charge into WW cases with WLR primers. Cases were FL sized and bullets were crimped with a Lee Factory Crimp Die. The powder was emptied from the Turk case directly into the WW case. Velocity was 2841 fps and average psi was 60,600. Extraction was smooth as a baby's butt with all 10 rounds tested.

Additionally I took the 10 Turk cases and NS'd them and loaded a Hornady 150 gr SP over 49.5 gr of milsurp 4895. This is a fine load that in the WW cases gives 2802 fps at 49,300 psi. Bolt lift and extraction are both also smooth as a baby's butt. That load in the Turk cases gave 2814 fps with a psi of 52,800. Bolt lift and extraction with the Turk cases was still sticky and no where as smooth as with the WW cases.

I've one large lot of Turk (1943) that averaged a psi of 58,700 at 2873 fps. I reduced the load 5% so the psi is now 49,000 at 2715 fps. About 10% of the cartridges still give some sticky bolt lift my 2 M48s and the M24/47.

Larry Gibson

Sorry Larry, inadvertently lumped you in with some of the other experts here-and elsewhere, looks like you did your homework, on this one anyway. With the data you provided I would guess the cause of heavy bolt lift and sticky extraction, IN THIS CASE(the LOTS of ammo TESTED), is caused by the properties of the turk brass.

seems like everytime that larry posts something on her y'all gotta tell him he is wrong.
i know larry somewhat,and buckshot some also.
if they say it IS.
i will believe them both.
if you take the time to actually read what larry is saying y'all might just learn something.
i have been reloading, casting, and generally breaking stuff, for 35 years now.
and know that larry does do his homework.
and his testing is well thought out[ and well carried out]
not to say he isn't ever wrong, but he does speak with some authority and plenty of experience.

Swheeler, Buckshot, and Lamar:

You would both do very well to actually READ what Larry Gibson posted, and then decide where he is right and where he is wrong.

For in the case of Turkish surplus ammo, he was both at the same time.

Carcano

F Y I ! The worst sticky extraction and hard bolt lift encountered was associated with 7.62 x51 CAVIM ( Venusuela? ) surplus brass. It was first noticed when firing it in a 1916 Mauser. Next when mildly reloaded for another .308. After that it gave the same performance in four of my X 41 wildcats, again mildly loaded.In every case it was "obvious" that the brass was SOFT, not brittle or hard. Both conditions do cause what appear to be similar problems.

The Turk powder and some of the German Flake powder obtained from pulled ammo look to be identical and perform about the same. Burning rate seems to be a tad slower then the 4198s. When reloaded in other cartriges they react very closly as does 4198.

Now armed with all this information the question that comes to mind is***" Why would anyone put 44gr. of 4198 behind a 196gr bullet in an 8 X 57 cartridge?***"???

Also some threads just out live other threads und Mox Nix. roger

Dear Roger: first of all, let me thank you for your very welcome and informative addition of another piece of experience.

quote:

Originally posted by bartsche:
The worst sticky extraction and hard bolt lift encountered was associated with 7.62 x51 CAVIM (Venezuela?) surplus brass. It was first noticed when firing it in a 1916 Mauser. Next when mildly reloaded for another .308. After that it gave the same performance in four of my X 41 wildcats, again mildly loaded. In every case it was "obvious" that the brass was SOFT, not brittle or hard. Both conditions do cause what appear to be similar problems.

This addresses the first element of my animadversions: the first issue, where Larry was (partially at least) right.

quote:

The Turk powder and some of the German Flake powder obtained from pulled ammo look to be identical and perform about the same. Burning rate seems to be a tad slower then the 4198s. When reloaded in other cartriges they react very closly as does 4198.

Many thanks. As I believe to remember (and I will be glad about more precise information), the burning characteristics of flake powders are mostly dependent upon their flake dimensions, while their respective chemical compositions do not seem to be far apart.

I will follow up in a second posting. Thanks so far!

Carcano

Carcano91

It would be polite if you would not only criticise that I was wrong and right but would also say specifically where I was wrong. The site you posted previously does not disagree with what I've posted here.

Could you kindly state where I was wrong and be specific in an explanation as to why?

Larry Gibson

quote:

Originally posted by Lamar:
... if you take the time to actually read what larry is saying y'all might just learn something. ....

Hey Lamar, What do you think about someone Hunting Elk with a 223Rem?

What do you think about a person posting totally misleading Pressures from a guessed at dimension, non-calibrated, fudge factored strain gauge fiasco as if it had any significance to any other rifle ever made?

What do you think about a person who "claims" that buying a HSGS(aka Fools Gold) makes them a "Superior Reloader"?

The reason people laugh at larry is simple.

quote:

Sounds like you got some de-linked machinegun ammunition. You did the right thing when you decided not to shoot it with signs of high pressure.

That was my first thought. I went to a military sponsored shoot and fired off nearly 500 rounds of 303 ammo in my 1902 Lee Enfield. I noticed the bore was a bit smoother near the muzzle. I chronographed one or two of those rounds and they turned out to be machine gun ammo! Headspace was only slightly altered. But all the evidence presented here shows Larry's explanation to be the correct one. Besides, he was pretty thorough in his testing!

quote:

Originally posted by Hot Core:

quote:

Originally posted by Lamar:
... if you take the time to actually read what larry is saying y'all might just learn something. ....

Hey Lamar, What do you think about someone Hunting Elk with a 223Rem?

What do you think about a person posting totally misleading Pressures from a guessed at dimension, non-calibrated, fudge factored strain gauge fiasco as if it had any significance to any other rifle ever made?

What do you think about a person who "claims" that buying a HSGS(aka Fools Gold) makes them a "Superior Reloader"?

The reason people laugh at larry is simple.

Hot Core

As usual, you state things out of contxt only to be arguementative and misleading. I never said I "hunted" elk with a .223. I said I killed elk with a .223. There is a big difference. I was a LEO in NE Oregon for many years and dispatched several injured elk most of which were poorly shot with much larger cartridges. I "killed" several of them with the .223.

Your other comments are your usual biased (or is it just plain jealousy?) comments because something more technologically advanced and much more accurate to measure pressures has supplanted your beloved CHE. The others here who read you rediculous comments see those comments and who made them for what they are.

It would be nice if you could add something intelligent to this discusion other than your usual drival. To that attempt let me ask you what does CHE say about the pressures of Turk milsurp ammunition?

Larry Gibson

bartsche

"The Turk powder and some of the German Flake powder obtained from pulled ammo look to be identical and perform about the same. Burning rate seems to be a tad slower then the 4198s. When reloaded in other cartriges they react very closly as does 4198.

Now armed with all this information the question that comes to mind is***" Why would anyone put 44gr. of 4198 behind a 196gr bullet in an 8 X 57 cartridge?***"??? "

My impression of the German flake powders is that they are very close to 3031 in burning rate. Equal weights of each powder produce close to the same velocity (I've not pressure tested that comparison on chronographed) when other componants are equal. 3031 is, as you say, a little slower than 4198. Intersting to note that the '54 & '55 Ecuadrian SS ammo with 196 gr bullets had 45 gr of such powder with peak average pressure of 52,800 and 52,500 psi(M43). The Turk ammo had 48 gr of the same type powder and exhibited much higher pressure with the ligher bullet.

Seem that the loaders and users of such ammo had no qualms with it. Considering the M98 is the most prolific rifle known with 118+ million having been made and how many bajillion rounds of 8x57 must have been made and fired through M98s. The Turk velocities match those of old German WWII ammo so I suspect the pressures of the German 8x57 ammo (type of powder and weight is almost identical to that used in Turk and Ecuadrian ammo) are pretty much the same.

Larry Gibson

quote:

Originally posted by Larry Gibson:
It would be polite if you would not only criticise that I was wrong and right but would also say specifically where I was wrong. The site you posted previously does not disagree with what I've posted here.

Could you kindly state where I was wrong and be specific in an explanation as to why?

You are welcome. But I shall instead begin where you were right, because that is IMO the more important issue.

1.
You were right in reminding us that "sticky cases" are not (repeat: NOT) any viable pressure indicator. As a pressure sign, case "stickiness" is at least as unreliable as the look of a fired primer, and maybe worse.

a) A case may have high overpressure, and still may extract nicely. On the other hand, as you have noted, a case may stick and exhibit hard extraction, and yet the chamber pressure may be entirely within safe limits.

b) Case brass changes its material properties with age and with work. Cases that have been reloaded (esp. several times) will perform differently from new cases. For reloaders, work hardening will be more important than age; while for surplus ammo shooters, the latter criterion may be more visible.

c) It would not be correct to link stickiness (chamber adhesion) with brittleness.
- A case with higher copper content in its brass will be more ductile (the opposite of brittle) and for this very reason will be harder to extract (also see Roger Bartsche's posted experiences as to this effect).
- On the other hand, harder (even up to "brittle") cases may crack, but nevertheless will often extract nicely.

d) Metal specialists (and bell-founders) might quite easily guesstimate the material composition and hardness of a case from its sound when struck. I do not have this knowledge, alas.

e) It is correct that older brass (military and _especially_ civilian) may have been subjected to unknown storage conditions (especially severe and repeated temperature changes) and thus may have become less resilient over the years and decades.
It is also true that brass compositions may have varied from year to year and from subcontractor to subcontractor.

2.
You were wrong when deducing from the above facts that Turkish 8x57 IS military surplus ammunition which seemed to "exhibit pressure signs" (unreliable as those often are, as I concede) would in fact not have been overpressure.

As explained above via link, *some* batches of Turkish ammunition were found to exhibit far higher muzzle velocities, which is at least a strong hint to higher pressures. Velocity chronographing is no substitute for pressure test barrels, but is an important and very useful information, and no reloader should be without (at least access to) a chronograph.

* * *

Lastly, I would like to add a few thoughts about the use(fulness) and the limits of strain gauges. I think they can be a very useful gimmick, within their limits, but I will be glad if Hot Core or Larry Gibson can correct or teach me more in this respect.

a) Like any pressure measurement tool (indeed, like a copper crusher or piezo gauge), a strain gauge must be calibrated and re-calibrated before use. If not, it will only deliver relative data ("my loudenboomer eargehplitten handload, tailored to stop the most ferocious charging dik-dik in its tracks, delivered 50 % more pressure reading than the same caliber remchester factory load").

b) One properly would use specially loaded SAAMI or CIP reference ammunition to calibrate a strain gauge. Still, this will only tell you how the presure was in the *test* barrel, not in the specific gun's barrel. A oad that will give 90 % percent maximum allowed use pressure in a test barrel (manufactured to CIP minimum specifications) may deliver 80 % pressure in your personal gun and its wider chamber. It might deliver 130 % in your benchrest barrel.

c) I had thought that to properly atttach a strain gauge to a barrel, that barrel and its blueing will be afflicted not insignificantly. It would not be just a put-on-put off afffair. Is that correct?

d) Factory ammo is always loaded to some percentage *below* the max allowed pressure. Also, factory ammo is NEVER loaded to the pressures that you see printed in the catalogues either, but below it. If your tested factory ammo thus shows 1764.89 oompaboompa units of personal strain gauge pressure, this does NOT equate to the "4000 piezo bar" of pressure that you saw printed in the factory catalogue. It may equate to 3670 or to 3800 piezo bar in a CIP test barrel or whatever.
The only thing that one thus could safely assess is that in most cases (not always, alas), a handload that does not exceed factory ammo pressures is reasonably safe.

Carcano

Carcano's last post is, in my opinion, correct. Extraction is no direct indicator of brass hardness, nor vice-versa.

The only problem I have with the original Gibson post in this thread, aside from equating hardness directly with extraction ease, is the comment that necks of Turkish ammo are not annealed at all. (quote:Note most all the necks of Turk ammo have not been annealed at all. unquote) He started out right, saying "insufficiently annealed", but errs, I think in that last part.

Having some limited knowledge of how drawn cartridge cases are manufactured in large numbers, I find that simply not credible.

I certainly do agree it is possible that they are insufficiently annealed after the final draw to keep them from splitting, but not annealed at all? I sincerely remain to be convinced of that.

With insufficient drawing for longer shelf-life, and age-hardening taking place, ammo may become sufficiently hard as to both split (often without firing at all, called "season-cracking") and to cause other problems.

In fact, that may well be why the Turks dumped it as surplus. You can maanufacture ammo more cheaply if you cut corners on such things as annealing. The price of that short-term savings is that service life is reduced as well.

Every government arming troops has to determine how/where it wants to spend available funds. Certainly they MUST do basic annealing to keep manufacture rolling without excessive waste. They will also do it well enough to keep "young" ammunition extracting well enough to allow rates of fire to meet requirements.

But, as the ammo ages, the intial savings may become a liability if the ammo no longer meets established functional specs. Then it is usually surplused either as ammo or as components, depending on what appears to be happening to it (and political considerations).

Basically, I wouldn't worry qbout the pressures. Powder is not going to get stronger as the ammo ages. Brass IS going to get less servicable, no matter how well initially made.

So, I'd go with Bartsche and others above. If it doesn't work the way I like, I'll dump or modify what I've got, and probably buy something else in the future.

quote:

Originally posted by Larry Gibson:
bartsche

"The Turk powder and some of the German Flake powder obtained from pulled ammo look to be identical and perform about the same. Burning rate seems to be a tad slower then the 4198s. When reloaded in other cartriges they react very closly as does 4198.

Now armed with all this information the question that comes to mind is***" Why would anyone put 44gr. of 4198 behind a 196gr bullet in an 8 X 57 cartridge?***"??? "

My impression of the German flake powders is that they are very close to 3031 in burning rate. Larry Gibson

Personally, Larry, I find the burning rates between 4198 and 3031 of significant difference. This thread seems to be deviateing into a " my ass is blacker than your ass type of thing." Like I said Mox Nix who gives a big rat's ass.

We see something happening and being alerted is a good thing. The philosophy of why it is happening in this case does not seem to carry much weight. The bullet pulling and the powder reduction appears to be senseable.

This seems to be appropo so I'll share it with you. At the time of my divorce from my first wife we were having an arguememnt. I said " Hey I'm right and you know I'm right." She said " Roger, I've never met a person like you who really is right as much as you are, and I really mean that, But who needs you ? Not me."

Talk about an attitude adjustment! **Me , Right than. Turning point ? You bet. roger

In another thread ( https://forums.accuratereloading.com/eve/forums/a/tpc/f/3221043/m/772109658/p/1 ), Alf posted excellent information which I feel bears a repetition here in this context:

ALF
Posted 07 May 2008 05:48

My take on the subject of pressure measurement:

Hotcore is actually correct in his assumption regarding the HSGS allbeit not very diplomatic about it

The problem with the GSGS system lies in what it actually measures or not.

It does not measure absolute pressure, but measures the strain behaviour of barrel steel to pressure.

Herein lies the problem !

Without a direct reference or datum point from where unit of pressure can be calibrated or referenced to a unit of strain in the barrel metal the system is lost.

if we choose a reference load ( calibration load) then all we can say is that the system measures more or less value than the reference load.

Even the reference load's value would not be asbolute for that gun, its pressure value is only absolute within the test barrel it was generated in and even there it is approximated.

In fact this is the achilles heel of the system. If not all systems.

If we look at CIP generated values they define that values are "average" and not absolute, they do define statistically validated values again by definition not absolute.

There is relatively little problem calibrating the unit of strain in the gauge to the electric pulse seen on a screen, the problem is how to calibrate the unit of strain of the steel to a unit of pressure generated in the chamber.

Professional use of these systems in military systems rely on mathematical equations with small margins of error to reference pressure against unit of strain in barrel steel, thus even here the measurement is not absolute but approximate based on reasonably accurate assumptions regarding mechanical behaviour of certain steels and constructs to stress.

The system assumes that the barrel steel has mechanical behaviours of certain magnitude and this is plugged into the mathematical equations from which the system is calibrated.

This brings about a certain margin of error inherent to the methodology. So in reality the measurement is always approximate!

It does however not mean the system is useless, far from it. It is useful as long as credence is given to the error of approximation and the error windows are defined.

Having said this the same can be said of measuring plastic deformation of the case with CHE/PRE methods.

Here we measure by analog means the plastic deformation of a metal ( brass) to strain ( pressure)

The problem is that there is poor consistancy in amount deformation to strain, Not to speak of the errors in the way we measure deformation. It is not linear, nor is it constant because of the variations and changes in mechanical behaviour from case to case and from shot to shot.

The danger of this method lies in the fact that the brass may not deform even if high rates of strain is applied, the reloader then assumes all is safe when in fact pressures may be at potentially catastrophic levels. ie the dangers of the false negative test result.

* * *

On page 2 of the same thread, Gerard Schultz also posted an important cautioning wuth regard to thuse judicious use of chronographs, as I had recommended:

Gerard
Posted 12 May 2008 12:43

The danger associated with blindly using a chrono and associating the speed with pressure is that, at the same speed, two different powders can give widely differing pressure levels. One may be safe and the other not. You will see we place the "do not exceed" speeds on our website in relation to specific powders and often the "do not exceed" speeds differ, within a caliber/bullet combination, for different powders.

The bottom line is that chrono use is common amongst reloaders and pressure testing equipment is not. Neither is perfect, so we must make do as best we can with what is available and use it intelligently in the individual situation.

Powder characteristics change over time so published load data revision must also be done from time to time. I am doing that at the moment but it is a slow process.

quote:

Originally posted by bartsche:

quote:

Originally posted by Larry Gibson:
bartsche

"The Turk powder and some of the German Flake powder obtained from pulled ammo look to be identical and perform about the same. Burning rate seems to be a tad slower then the 4198s. When reloaded in other cartriges they react very closly as does 4198.

Now armed with all this information the question that comes to mind is***" Why would anyone put 44gr. of 4198 behind a 196gr bullet in an 8 X 57 cartridge?***"??? "

My impression of the German flake powders is that they are very close to 3031 in burning rate. Larry Gibson

Personally, Larry, I find the burning rates between 4198 and 3031 of significant difference. This thread seems to be deviateing into a " my ass is blacker than your ass type of thing." Like I said Mox Nix who gives a big rat's ass.

We see something happening and being alerted is a good thing. The philosophy of why it is happening in this case does not seem to carry much weight. The bullet pulling and the powder reduction appears to be senseable.

This seems to be appropo so I'll share it with you. At the time of my divorce from my first wife we were having an arguememnt. I said " Hey I'm right and you know I'm right." She said " Roger, I've never met a person like you who really is right as much as you are, and I really mean that, But who needs you ? Not me."

Talk about an attitude adjustment! **Me , Right than. Turning point ? You bet. roger

Hell Bartsche

And there I thought I was pretty much agreeing with you and just adding to your thoughts! I still agree with you anyway.

Larry Gibson

Carcano91

Appears that you, like Hot core make a lot of assumptions on what I do or don't do and how I conduct tests.

I do thank you for your post, it is most enlightening and is a fairly objective analysis of using brass obturation as a pressure sign. However in this case the test concerns just just the Turk ammo and those lots that do exhibit sticky extraction. Youa also seem to imply things that i did not. for example;

You state in this post; "You were wrong when deducing from the above facts that Turkish 8x57 IS military surplus ammunition which seemed to "exhibit pressure signs" (unreliable as those often are, as I concede) would in fact not have been overpressure.

As explained above via link, *some* batches of Turkish ammunition were found to exhibit far higher muzzle velocities, which is at least a strong hint to higher pressures. Velocity chronographing is no substitute for pressure test barrels, but is an important and very useful information, and no reloader should be without (at least access to) a chronograph."

Then in the later post; "On page 2 of the same thread, Gerard Schultz also posted an important cautioning wuth regard to thuse judicious use of chronographs, as I had recommended:

Gerard
Posted 12 May 2008 12:43

The danger associated with blindly using a chrono and associating the speed with pressure is that, at the same speed, two different powders can give widely differing pressure levels. One may be safe and the other not. You will see we place the "do not exceed" speeds on our website in relation to specific powders and often the "do not exceed" speeds differ, within a caliber/bullet combination, for different powders.

The bottom line is that chrono use is common amongst reloaders and pressure testing equipment is not. Neither is perfect, so we must make do as best we can with what is available and use it intelligently in the individual situation."

First you say that chronographed results demonstrate over pressure in Turk ammo and that I am wrong. Then say and quote another to reinforce your point that the use of a chronograph is not reliable as an indicater of over pressure. So which is it?

I to have chronographed certain lots of Turk ammo out of 29 1/2" barrels that exceeded 3000 fps with one lot just over 3000 fps. However most anyone knows there is a considerable velocity difference between a 29 1/2" barrel and the 23" barrel (M98 24/47) used in my test. If you'll note in my post I stated; "Even the lot with 53,000 psi still gave the same "sticky bolt" opening as the higher pressure loads." The reason is because brittle brass does not "springback" like annealed brass. It expands and stays expanded. Sometimes it splits. This is what is causing the "sticky bolt lift" even with the 53,000 psi lot. I reduce dthe load down to 49,000 and still had 10" sticky bolt lift. I also put the Turk load in W_W cases and the velocity and pressure was almost identical to the Turk case velocity and pressure. Yet there was no sticky bolt with the W-W cases. that telss me, and most who understand, that the Turk cases are brittle and not springing back.

Since you asked I'll explain and answer some of your other questions about the proper use of this "gimmick".

“a) Like any pressure measurement tool (indeed, like a copper crusher or piezo gauge), a strain gauge must be calibrated and re-calibrated before use. If not, it will only deliver relative data ("my loudenboomer eargehplitten handload, tailored to stop the most ferocious charging dik-dik in its tracks, delivered 50 % more pressure reading than the same caliber remchester factory load").â€

Your assumption that it must be calibrated is correct. The M43 is calibrated at the factory when made. As to the M43 needing to be “re-calibratedâ€, it is just not so. Perhaps you misunderstand this from Hot Core’s constant rants. Do you think that the ammunition makers “calibrate†their own pressure machines by adjusting something so when “reference ammunition†is fired the numbers from their pressure machine then are the same as what the pressure of the “reference ammunition†is supposed to be? There is no such thing a “calibration ammunitionâ€, it is reference ammunition and right now only Winchester makes it not SAAMI. It just doesn’t happen that way. The reference ammunition has a set of specifications as to the condition in which it gives X amount of pressure based on Winchesters pressure measurements. Then when another ammunition maker fires it under those conditions but in their pressure barrel/machine and they get a psi 3,000 different they merely use that as an offset in the computation of pressure reading of other ammunition. Now as you state in “b†below this only tells the ammunition manufacturers what the pressure is in their one test barrel. You don’t think they have a bunch of test barrels for a specific cartridge do you? No they don’t. They test their ammunition in that one test barrel to make certain the loaded ammunition is below the MAP. Most companies then chronograph those pressure tested loads in production firearms with a nominal barrel length. You’d be surprised how many ammunition manufacturers use the Oehler M83 with strain gauges attached to these production firearms. The M83 is somewhat more sophisticated than the M43 and the m83 is a “laboratory†instrument as Hot Core likes to rant about. It is expected in these tests that the production ammunition will give less pressure in production chambers and barrels than it does in minimal spec SAAMI pressure test barrels.

For example I contacted Federal (very nice to talk to and very cooperative) and advised them of my about to be conducted tests with 3 different lots of their .308W ammunition. I gave them the lot #s and asked if they could tell me the psi of those lots when they pressure tested them in their SAAMI test barrels. With in 24 hours I had the answer and also was advised of the ambient temperature, the barometric pressure and the humidity. I waited for a day when the temperature would attain 70 degrees. The humidity and barometric pressure were close but not quite the same. When the ambient temperature had been 70 degrees for an hour I ran the test. With a relatively new barrel with minimum headspace the pressure I recorded were very near the federal test pressure only slightly below with the farthest off being 2100 psi. In the game of measuring pressures that is pretty darn close. Ever wonder why they only list pressures in thousands of psi or 100 psi at a minimum? It is because just like with a chronograph when you shoot to strings of 10 shots of the exact same ammo out of the same rifle the average velocity most often will not be exactly the same. And so it is with pressure measuring machines. In the test with the Turk ammo I have also chronographed different lots of American ammunition and the psi recorded on the M43 is consistent with published data from the ammunition makers. I also have tested the .308, the 30-06, the 30-30, the 8x57, the 6.5x55 and the .223 cartridges in two or more rifles of each cartridge. None of the pressures were the “same†given the same ammunition in two different rifles. They were always close, but never the same. The psi of all those cartridges was where the published information said it should be. That is to be expected and it is why the ammunition factories load below the MAP for the most part. I have found milsurp ammunition to be most often otherwise.

I recently ran some tests of .223 ammunition. I found Remington factory 50 HPs to be at 52,900 psi(M43). That is slightly below the MAP for commercial .223. The velocity was 3280 fps which is about right for a 50 gr HP out of a 21†barrel. At the same store and at the same time I also purchased a box of Winchester white box .223 ammunition that is the 55 gr fmj M193. The headstamp was WCC07. The psi(M43) was 65,700! The velocity was 3351 fps out of the 21†barrel. That is hot by anyones standard. Now are you, Hot Core or anyone else going to say the 65,700 psi with the M193 was wrong when the 52,900 psi with the Remington ammo was where it should have been? I don’t think so. The primers were severely flattened on the M193 ammo. There was no CHE BTW.

“b) One properly would use specially loaded SAAMI or CIP reference ammunition to calibrate a strain gauge. Still, this will only tell you how the presure was in the *test* barrel, not in the specific gun's barrel. A oad that will give 90 % percent maximum allowed use pressure in a test barrel (manufactured to CIP minimum specifications) may deliver 80 % pressure in your personal gun and its wider chamber. It might deliver 130 % in your benchrest barrel.â€

Who, other than Hot Core and now you, say “One properly would use specially loaded SAAMI or CIP reference ammunition to calibrate a strain gaugeâ€? The manufacturer doesn’t. The ammunition manufacturers I talked with didn’t. Winchester even convinced me not to use their reference ammunition but to use various lots of factory ammunition. They too provided their test pressures (not the other information that federal provided though). You are absolutely right in that a pressure test with a strain gauge “will only tell you how the pressure was in the *test* barrelâ€. However let us remember that the test pressure of SAAMI test barrels also only tells us what the pressure was in the test barrel. It does not tell you nor I nor anyone else what the pressure will be in our rifles. So what is the difference? Not much except that since my barrels are production barrels and not minimum spec SAAMI chambers/barrels then the pressure could vary between your rifle and mine, probably not by much based on my tests. I seriously doubt your thoughts of 130% over pressure above SAAMI MAPs would occur as SAAMI specs for pressure chambers and barrels are even more stringent than even most benchrest rifles. Besides building a custom benchrest rifle with minimal specs is not going to fired with factory ammunition, now is it. Let’s try to remain reasonable here, shall we?

c) I had thought that to properly atttach a strain gauge to a barrel, that barrel and its blueing will be afflicted not insignificantly. It would not be just a put-on-put off afffair. Is that correct?

That is correct. I take remove the bluing to the bare metal to attach the strain gauge. Once attached it is permanent. The gauge is ruined if removed. Also before a test is started the computer runs a check on the strain gauge to measure if it is good to test.

“d) Factory ammo is always loaded to some percentage *below* the max allowed pressure. Also, factory ammo is NEVER loaded to the pressures that you see printed in the catalogues either, but below it. If your tested factory ammo thus shows 1764.89 oompaboompa units of personal strain gauge pressure, this does NOT equate to the "4000 piezo bar" of pressure that you saw printed in the factory catalogue. It may equate to 3670 or to 3800 piezo bar in a CIP test barrel or whatever.
The only thing that one thus could safely assess is that in most cases (not always, alas), a handload that does not exceed factory ammo pressures is reasonably safe.â€

Psi†as used with strain gauges, conformal transducers and piezoelectric transducers (several types, ) are calibrated in their respective computers to give the same value of “psiâ€. On the other hand the older C.U.P. method required a tarage table to calculator the amount of “psi†required to deform the copper cylinder. The correlation between C.U.P. “psi and the modern electrical measurement of “psi†is troublesome in that while there can at times seem to be a correlation at other times there is not. Ammunition makers use components that when assembled provide ammunition that meet a certain performance criteria. The purpose of the MAP is to provide a fudge factor. Testing is most often done at a certain ambient temperature. The fudge factor allows ammunition to not exceed dangerous levels when fired in extremely hot temperatures. Thus most factory ammunition pressures are below the MAP as you’ve noted. I’ve also mentioned that numerous times in other threads regarding discussions of factory ammunition pressures. There are those that believe every round of ammunition the shoot is loaded to the maximum allowable pressure.

“The only thing that one thus could safely assess is that in most cases (not always, alas), a handload that does not exceed factory ammo pressures is reasonably safe.†That is very much the case.

In your follow on post you state; “The problem with the GSGS system lies in what it actually measures or not.
It does not measure absolute pressure, but measures the strain behaviour of barrel steel to pressure.
Herein lies the problem !â€

What you and Hot Core don’t seem to understand is that is the case with EVERY method of pressure measurement. None of them measure the “absolute pressureâ€. The C.U.P. measure the behavior of pressure on a copper cylinder. The gas piezoelectric transducers measure the behavior of pressure of the flowing gas (these are at the case mouth and measure pressure there and a fudge factor for the ventura effect of the gas has to be taken into account). When located on the case itself these can be accurate but since a hole is drilled into the case the integrity of the case is destroyed so a fudge factor for that must be built in. SAAMI uses a conformal transducer which has problems of its own. The point here is that measurements from all of these devices can be quite equivalent. Also consider that industry insiders (ballisticians) generally consider an accuracy level of 95-98%. That may or may not seem very good but let me quote Dr. Oehler; “this degree of error (2-5%/best case – worst case) may appear huge in comparison to the three or four digit accuracy expected from inexpensive digital voltmeters or mechanical micrometers, it is comparable to actual pressure variations seen from one “identical†barrel to a second “identical†barrel or with typical lot-to-lot variations in powder burning rates.†We should also note that CHE measures the behavior of pressure on brass. Thus we see they all have problems. Tests have demonstrated the use of the strain gauge (numerous ammunition manufacturers use them) give consistent pressure measurements in psi as do the other modern methods. Is that psi measurement only relative to that rifle/chamber? Yes, just the same as the factory pressure is only relevant to the test barrel/chamber.

Bottom line is I’ve tested factory and handloads of several different cartridges in several different rifles of the same cartridges and found the variations in pressures to be within expected between pressure barrels. A load that is safe in one rifle has proven safe in another. That is the same result as the factories expect when they sell their ammunition. There are indeed certain “mechanical behaviors of certain magnitude†plugged into the computations by the M43. These are industry standard and accepted engineering principle and facts. They have proven to be correct.

Larry Gibson

quote:

Originally by larry:
As usual, you state things out of contxt only to be arguementative and misleading. I never said I "hunted" elk with a .223. I said I killed elk with a .223. There is a big difference. I was a LEO in NE Oregon for many years and dispatched several injured elk most of which were poorly shot with much larger cartridges. I "killed" several of them with the .223.

Lets get this one out of the way since I saved a link to it - larry and the 223Rem on Elk. It will be found near the bottom of the thread after I'd mentioned larry's hero - teanscum - was using a 223Rem on Mulies. I'll let you all decide if the "context" of larry's comment led me to believe he was Hunting Elk or not.

So larry was a doughnut-eating, radar-runner for many years. That sure explains a lot to me.

quote:

Originally posted by carcano91:
Lastly, I would like to add a few thoughts about the use(fulness) and the limits of strain gauges. I think they can be a very useful gimmick, within their limits, but I will be glad if Hot Core or Larry Gibson can correct or teach me more in this respect.

The chance of larry teaching anyone anything other than eating doughnuts just isn't in the world of probability.

A properly measured, Calibrated Strain Gauge System, with the known Correction Factor, in a Lab Environment is indeed useful. On the other hand, a HSGS=Pyrite(aka Fool's Gold)

quote:

a) Like any pressure measurement tool (indeed, like a copper crusher or piezo gauge), a strain gauge must be calibrated and re-calibrated before use. If not, it will only deliver relative data ("my loudenboomer eargehplitten handload, tailored to stop the most ferocious charging dik-dik in its tracks, delivered 50 % more pressure reading than the same caliber remchester factory load").

Carcano nailed it exactly. That is the reason the HSGS is misleading at best and dangerous when people who really don't understand how they work - like larry - start spouting off all kinds of Pressure Data as if it was significant. The Beginners and Rookies who do not know better will be mislead into believing larry has some worthwhile knowledge.

quote:

b) One properly would use specially loaded SAAMI or CIP reference ammunition to calibrate a strain gauge. Still, this will only tell you how the presure was in the *test* barrel, not in the specific gun's barrel. A oad that will give 90 % percent maximum allowed use pressure in a test barrel (manufactured to CIP minimum specifications) may deliver 80 % pressure in your personal gun and its wider chamber. It might deliver 130 % in your benchrest barrel.

Correct again. However, once you use the Calibration Ammo(Reference Ammo) with the HSGS, it will allow the user to establish a "Correction Factor" and then it becomes a useful Strain Gauge System. That is the same way it is done in the factories - they establish a Correction Factor based on the Calibration to a known Standard. Once that is known, then the Data derived from that specific firearm would in fact be Significant Data - in relation to the SAAMI Standard.

quote:

c) I had thought that to properly atttach a strain gauge to a barrel, that barrel and its blueing will be afflicted not insignificantly. It would not be just a put-on-put off afffair. Is that correct?

Correct for the 3rd time. Plus you have the "nest of wires" to deal with at a Range. In a Lab Environment, all that can be routed under the floor or through conduit to keep it out of the way.

quote:

d) Factory ammo is always loaded to some percentage *below* the max allowed pressure. Also, factory ammo is NEVER loaded to the pressures that you see printed in the catalogues either, but below it.

Once the factory knows the Correction Factor, they load relatively close to the SAAMI Pressure. But there is always a "Range" of + or - X,000psi. The Range is dependant on all Components being used in the Cartridge.

quote:

If your tested factory ammo thus shows 1764.89 oompaboompa units of personal strain gauge pressure, this does NOT equate to the "4000 piezo bar" of pressure that you saw printed in the factory catalogue. It may equate to 3670 or to 3800 piezo bar in a CIP test barrel or whatever.
The only thing that one thus could safely assess is that in most cases (not always, alas), a handload that does not exceed factory ammo pressures is reasonably safe.

Correct for the 4th time

I'd suggest that Carcano could easily teach larry a lot, however the ability for larry to grasp anything of significance is like talking to a mule. With one exception, the mule can learn.

I will address elk hunting when I feel in the mood ;-).
In the meantime, I wish to thank Larry for his long and substantial answer to my posting. You have shown the same politeness that you have asked me for, and we might get a fruitful discussion going.

Merci, Carcano

Hey Carcano, I had to STOP for a few minutes on my above post. During that time you posted and it appeared I'd not responded to you. That was not my intent - just a timing issue.

You have an excellent grasp concerning Strain Gauge Systems and HSGSs.

Well it looks like we're all back on track! Larry ! Nothing personal. Some times my brain misinterprets and signals my key board to over-ride my ass hole. roger