[B]Load Manual Error......[/B]

[Larry Gibson]

Loading Manual Error……

Over the years, especially the last nine years with an Oehler M43 actually pressure testing, I’ve discovered error in data in almost every make (Speer, Lyman, Hornady, Hodgdon and Nosler) of loading manuals. This is especially the case with data from older and newer manuals that list pressures derived from the C.U.P. method of testing. Lee’s manual simply copies the data from other sources, both C.U.P. data and modern psi data obtained from transducer/strain gauge pressure measurement. Many newer manuals have loads “adjusted”, usually down, from the data in older manuals. Many think this is from lawyers, etc. but the truth is most newer reloading manual data is derived from better and more complete pressure testing through the use of peizo-transducers and strain gauge measurements. What is found is many older loads that were thought to be within safe standards for the cartridge actually were too high in pressure.

A recent example has been found using H4350 in the 30-06 with Hornady’s new 178 gr ELD-X bullet. A friend of mine recently had goodsteel build him a long range rifle based on a M700 action. It has a 31” Palma contoured barrel with a 12” twist chambered in 30-06 XCB. Based on my previous experience with ’06 match rifles and long range rifles I suggested 4350 powder. He collected a good amount of all three flavors; IMR, Hodgdon and Accurate Arms. He also got a supple of 175 Sierra MKs and the new Hodgdon 178 ELD-X bullets. He is using Winchester match prepped cases and Federal 215 Match primers.

He decided to try the Hodgdon’s H4350 powder and turned to the Hodgdon #27 manual. One would assume Hodgdon had the data well tested and correct since it’s their powder. We were discussing the loads by phone (he is in NE Oregon and I’m in Arizona) so I opened up my Hodgdon #27 manual and turned to the data for the 30-06 with 180 gr bullets. The #27 manual lists the max load for 180 gr bullets using H4350 at 57.5 gr. That is with a C.U.P. of 49,200. The velocity listed from a 24” Winchester M70 barrel with a 10” twist at 2798 fps. I have not used H4350 in the 30-06 (I mostly use IMR and AA) so I took the data at face value.

My friend decided to work up from 54 gr in ½ gr increments to 57.5 gr of H4350. A few days later he called back just tickled pink as the 57.5 gr load was shooting right at ½ moa at 300 yards. He had broke down and bought the top end Chrony with printer but hadn’t yet chronographed it. I was up there a few weeks back on my way to the Tacoma area. We went out to the local range and set up the Chrony and chronographed the 57.5 gr load. There was no indication of excessive pressure; bolt opened normally, primers looked fine and no excessive expansion at the case head. But holy smokes…..the average velocity was 3060 fps!!!!! My prediction with either AA4350 or IMR4350 under a 175 gr Sierra MK was 2950 fps +/- given the 31” barrel……but 3060 fps? About 3 weeks later I returned back through there so we took the rifle up to another friend’s ranch where they have a 1000 yard range with a sturdy bench to shoot from. He put 9 shots consecutively into right at 1 moa at 1000 yards in a 5 -8 gusting to 10 mph side wind. I put 10 shots into 1.2 moa. Again, even though it was 80+ degrees there was no sign of excess pressure.

However, that night my friend was depriming the cases and three primers basically fell out of the pockets. The primer pockets were swollen and no longer would hold a primer. That was the first sign of excessive pressure. My friend gave me a pound of the H4350 and a box of the 178 ELD-Xs to bring home with me to pressure test that load. I have the Winchester cases and Federal 215 Match primers. When I got home I loaded test loads of 56.5, 57 and 57.5 gr. Yesterday morning at daylight I was at the range here in Lake Havasu to test those loads. Was 65 degrees so heat would not be a factor. My 30-06 test rifle is a M98 Mauser with a 24” barrel. I chambered it with a match reamer to minimal headspace. I gives pressure readings via the Oehler M43 that are commensurate with the known pressure of Federal and Winchester factory loads used as “reference ammunition”.

I shot a ten shot test with M72 Match to validate everything was set up correctly. The measured data was within normal range. I lightly cleaned the barrel and proceeded to test the 56.5 gr load. The test rounds were loaded in fire formed test Winchester cases NS’d with a Bonanza Bench rest NS die. Primers were Federal 215 Match. Powder charges were weighed with a Redding scale. The 178 ELD-Xs were seated to 3.330” which is just off the leade.

The Oehler M43 was set up to measure the pressure and velocity for each shot. Start screen was at 15 feet with a 4 foot screen spacing. Target was at 100 yards.

The 1st test shot went 2882 fps with 69,200 psi(M43)
The 2nd test shot went 2873 fps with 68,900 psi(M43)
The 3rd test shot went 2869 fps with 69,200 psi(M43)

I quit testing and did not fire the remaining 7 rounds of that load nor did I fire any of the heavier 57 and 57.5 gr loads. With the 69,000 psi +/- from the “start” load I sure wasn’t going any higher…….

Average for the 3 test shots was:
Velocity; 2875
PSI; 69,100

The M43 correction to muzzle velocity was 2884 fps. The 3 shots grouped .94”.

The 56.5 gr H4350 test load was 86 fps faster than the Hodgdon manual listed max load of 57.5 gr. Note the test barrels were both 24”. Obviously the psi of the 56.5 load was quite excessive. I hesitated to guess at the pressure of the 57.5 gr load but based on experience I’d guess it was 75,000 +/- psi….well into “proof level” loads.

On the return home I figured something was definitely amiss. I pulled the bullets of the cartridges not fired and reweighed the charges….they were spot on. I then looked at a couple burn rate charts and discovered my own “error”. H4350 is sandwiched right between AA4350 and IMR4350. My experience with both of those is that 56 gr is a max load (measured 60 – 62,000 psi) under a 180 gr Hornady SPBT. I then checked Hornady’s 8th and 10th Edition manuals. They list 55.3 gr H4350 as a max load under 178 – 180 gr bullets…….Hello......says I, there’s a 2.2 gr difference between the Hodgdon and Hornady manuals. The 2700 fps velocity level +/- is also commensurate with what I get out of my test rifle and M70 (24” barrels with 56 gr AA4350.

Examination of the fired cases revealed no sign of excessive pressure as shown here. They were fired left to right. The primers appear normal for a top end jacketed 30-06 load with 60,000 psi. 2nd photo shows the case as fired left to right with a fire formed case (far right) from a previous normal psi firing.

Again, no sign of excessive pressure, just normal expansion at the expansion ring after 3 firings.

204826204827

I’ve reloaded up test strings of 54.5, 55.0 ,55.3, 55.6 and 55.9 H4350 with all other load parameters being the same. Hoping to test before the week is out. I will post the results here.

Today September 28, 2017 I completed the test. I again set up at daylight with little to no wind and the temp right at 70 degrees. Results are;

54.5 gr; 2743 fps with 56,600 psi(M43)
55.0 gr: 2801 fps with 60,400 psi(M43)
53.3 gr; 2833 fps with 61,900 psi(M43)
55.6 gr; 2850 fps with 63,700 psi(M43)

I did not test the 55.9 gr load.

The maximum load listed in Hornady 8th and 10th editions is correct at 55.3. Any modern action also chambered in .308W ill also handle this psi level. I would consider the 54.5 gr load as maximum in older actions such as the M1903s.

The Hodgdon maximum load is 2.2 gr higher and obviously is too much.

This obvious error in older loading data with the pressure measured via the C.U.P. method is another example that care should be exercised when using older data, especially when the pressure is listed as measured with the C.U.P. method. New comers to reloading should head advice not to jump to the top load of a manual or to use loads given on internet sites and forums without consulting other references. Even then a reduction and proper work up should always be done.

A chronograph also is an excellent tool to use when developing loads, especially if one is going to approach top end jacketed loads. When the velocity is faster than the published data understand there is probably only one reason why; pressure.

Larry Gibson

[tazman]

Now that is interesting!!
Makes me wish I had pressure testing equipment.
Could it be a possibility that particular lot of powder has an issue that would cause that or is that really unlikely?

[JBinMN]

Thanks for taking the time to share that data!

I myself use older manuals, but I do not usually get up to max loads anyway. I work my way up slowly & look for possible issues as I go. But I do know some who do "push the envelope" a bit from what they have told me & not think a thing about doing it....

I hope that your discovery gets spread around so that you possibly save someone some grief in the future, for folks getting too complacent with their reloading at near max/max ( or over) powder amounts.

I will be passing your findings to the ones I know who reload. Then it is up to them to heed or not.

Thanks again for the share!
:)

[JimB..]

Thanks, but I have a question.

If the old testing methods tended to understate the actual pressure, how were max pressures determined?

[dragon813gt]

Out of curiosity I ran the numbers in Quickload for the 56.5 grain load. Obviously I don't have all the specifics for the loaded cartridge. Using the 30-06 SAAMI cartridge and ELD-X 3074 bullet it predicted 2848 fps at Pmax of 63,257 psi. It also says it's a compressed load of 8.2%. For those that don't have the pressure testing equipment that Larry has Quickload would have kept you out of trouble. If I entered all the specifics for the cartridge it could potentially raise the pressure even more.

[oldblinddog]

I have a Remington 700 .30-06 with the factory 1-10 twist barrel in which I am loading the 165 gr Speer SP (flat base) over 56.0 gr. of RL17 in Winchester cases with WLR primers. Alliant gives the max load for the 165 SPBT as 56.5 gr. My handload is very accurate in my rifle. However, I don't recall if I have chronographed this load yet. Might be time to do so. Also, this type information makes for a desire for pressure testing equipment as well.

Thank you, Larry, for your diligence in testing and also your willingness to publish your test results.

BTW, the Hodgdon website shows a max load in the .30-06 with the 175 gr Sierra match HPBT loaded to 3.300" as 59.0 gr. H4350 for 2842 fps and 48,700 C.U.P., which sounds fairly benign. Winchester case and WLR primer, 24" 1-10 twist barrel.

[Digital Dan]

Very well done Larry, thank you.

[Shuz]

Very well done Larry! This should be a "stickey"!

[tazman]

I agree with the stickey vote

[Outpost75]

In radial copper days all of the manufacturers would work off the same lot of reference ammunition in a given caliber, and each facility would fire a 20-round test, submitting their data, fired cases and used coppers for analysis. The data would be evaluated and Knoop hardness measurements made of the coppers to develop an assessment of each lot of reference ammo, which everybody used. If a particular pressure barrel gave different results from the assessment, a correction factor would be applied to tests performed in that barrel. Careful records were maintained on presure test barrels and once observed calues exceeded parameters permitted by the established calibration procedures, the barrel would be scrapped.

The basic calibration procedures were similar in government practice, but cases of test rounds were pre-drilled and a different size copper was used.

[swheeler]

Hornady #9 doesn't show H4350 with 180 bullet, but has IMR and Accurate 4350 with max loads of 54.5 and 54.4 @ 2700fps from a 23.75 " bbl. Be careful, start low and work up or you could put an eye out!:drinks:

[williamwaco]

I find that AMAZINGLY interesting. My mentors have always told me than none of the traditional pressure signs could be relied on to keep me safe. The reason is that by the time they appear it is already way too hot. They taught me that these signs appear at about - - - - > 70,000 psi.

[swheeler]

I find that AMAZINGLY interesting. My mentors have always told me than none of the traditional pressure signs could be relied on to keep me safe. The reason is that by the time they appear it is already way too hot. They taught me that these signs appear at about - - - - > 70,000 psi.

That sounds about right to me. What I do find surprising is that the 57.5 gr load Scharf was shooting in the Rem 700 didn't show brass extrusion into the ejector bore, a bright spot on the fired brass head.

[Preacher Jim]

Larry as always I find your information spot on thank you for sharing your expertise

[OS OK]

I find that AMAZINGLY interesting. My mentors have always told me than none of the traditional pressure signs could be relied on to keep me safe. The reason is that by the time they appear it is already way too hot. They taught me that these signs appear at about - - - - > 70,000 psi.

Sometimes with old eyes one has to get the magnifying glass out and study the radius on the shoulder. Close scrutiny will reveal that as pressure goes up that primer radius gets progressively smaller and smaller. Primers have to be looked at closely and also compare the whole lot of the test/workup...not just a couple.

[buckshotshoey]

I know there are differences from lot to lot, but DAMN! Even the best 168 he Matchking tops out a about 2700. One would think that someone would have run into trouble long before Larry studied this situation (not doubting your results Larry). It would be interesting to hear what Hodgdon has to say about this.

[44MAG#1]

What I have taken out of all this is that NO loading data from ANY SOURCE can be counted on 100 PERCENT of the time.
This is something most veteran reloaders will probably know but are subject to forget at times.
This episode should be enough to reinforce the idea that relying 100 percent on any source of load data is bordering on the irresponsible even from a person that one perceives to know what they are talking about.

[edp2k]

Hi Larry,

Just curious,
Have you/do you plan on contacting Hodgdon and forwarding them your data
on the apparent over pressure load data for Hodgdon’s H4350 powder in Hodgdon's #27 manual?

I know that it is a challenge trying to get the bureaucracy to correct it's actions.

[Larry Gibson]

Hi Larry,

Just curious,
Have you/do you plan on contacting Hodgdon and forwarding them your data
on the apparent over pressure load data for Hodgdon’s H4350 powder in Hodgdon's #27 manual?

I know that it is a challenge trying to get the bureaucracy to correct it's actions.

I've a couple more tests to run 1st. The #27 Hodgdon manual lists that 57.5 gr as max for a "180 gr bullet". So I'm going to test the 55.3 gr load again but with 4 different bullets; The Sierra 175 gr MK, the Hornady 178 ELD, a Hornady 180 SPBT and a Speer 180 gr SP. We'll see what happens with those first.

[44MAG#1]

They used the Sierra 180 SBT and a WLRP.

[Larry Gibson]

They used the Sierra 180 SBT and a WLRP.

I can do that too.

[pjames32]

Thanks for the reminder Larry. I have a pet load for my 7mm STW that is amazingly accurate, but based on early data. I need to rethink my load.

[44MAG#1]

Thanks for the reminder Larry. I have a pet load for my 7mm STW that is amazingly accurate, but based on early data. I need to rethink my load.

I know I don't have no where near the intelligence quotient that Mr Gibson has but if I had been using a load for years that has decent case life and showed no problems I wouldn't rethink anything.

[williamwaco]

What I have taken out of all this is that NO loading data from ANY SOURCE can be counted on 100 PERCENT of the time.
This is something most veteran reloaders will probably know but are subject to forget at times.
This episode should be enough to reinforce the idea that relying 100 percent on any source of load data is bordering on the irresponsible even from a person that one perceives to know what they are talking about.

That is a VERY important lesson. Exact the reason the old timers tell you to start low and work up.

[swheeler]

"However, that night my friend was depriming the cases and three primers basically fell out of the pockets. The primer pockets were swollen and no longer would hold a primer."

Brass extrudes in all directions so that tells me there had to be some indication of flow into the ejector hole, maybe minute but there. I guess if a load has been shot before and deemed safe it could be overlooked, but usually makes a bright mark as the bolt is rotated to eject. Maybe we could get a picture of the case heads of brass with loose primer pockets? Some of the older manuals were notorious for "hot loads" Hodgdon #26 shows 56.0 gr H4350 as max for 180 gr bullet but no manufacture is shown.

[oldblinddog]

That is a VERY important lesson. Exact the reason the old timers tell you to start low and work up.

The rest of the lesson is that because there is NO reliable method to determine pressure other than a transducer, published maximums using copper crusher are suspect and should be avoided unless you have other evidence to support your data. Other evidence would be chronograph data (at the least). Inspecting primers and case head expansion is bogus for most reloaders because they don't start from a known point or know how to keep proper records.

[OS OK]

The rest of the lesson is that because there is NO reliable method to determine pressure other than a transducer, published maximums using copper crusher are suspect and should be avoided unless you have other evidence to support your data. Other data would be a chronograph (at the least). Inspecting primers and case head expansion is bogus for most reloaders because they don't start from a known point or know how to keep proper records.

I haven't seen anyone claiming 'exact pressure' from reading the primers and measuring case heads...all that us old Greybacks are trying to say is that...we can see 'indication' of problematic pressures on the horizon.

[oldblinddog]

However, that night my friend was depriming the cases and three primers basically fell out of the pockets. The primer pockets were swollen and no longer would hold a primer.

Brass extrudes in all directions so that tells me there had to be some indication of flow into the ejector hole, maybe minute but there. I guess if a load has been shot before and deemed safe it could be overlooked, but usually makes a bright mark as the bolt is rotated to eject. Maybe we could get a picture of the case heads of brass with loose primer pockets? Some of the older manuals were notorious for "hot loads" Hodgdon #26 shows 56.0 gr H4350 as max for 180 gr bullet but no manufacture is shown.

The Hodgdon website shows the 57.5 gr load with the 180 Sierra SPBT at 2798 FPS and 49,300 CUP, same as the #27 manual cited by Larry in the OP.

[oldblinddog]

I haven't seen anyone claiming 'exact pressure' from reading the primers and measuring case heads...all that us old Greybacks are trying to say is that...we can see 'indication' of problematic pressures on the horizon.

Well, I am one of those Greybacks and I can remember articles in Handloader/Rifle debunking these methods. The point is/was that by the time you start to see any signs you are well beyond max pressures. Besides, there is no improvement in trajectory that you can't negate just by how you hold the rifle in the field. The pursuit of "max" velocity is a futile endeavor. Look at the loads used by our snipers shooting the .308/7.62x51. Best accuracy and knowing your load is better. But then, that's just my opinion.

[OS OK]

Well, I am one of those Greybacks and I can remember articles in Handloader/Rifle debunking these methods. The point is/was that by the time you start to see any signs you are well beyond max pressures. Besides, there is no improvement in trajectory that you can't negate just by how you hold the rifle in the field. The pursuit of "max" velocity is a futile endeavor. Look at the loads used by our snipers shooting the .308/7.62x51. Best accuracy and knowing your load is better. But then, that's just my opinion.

I agree...I never found a max. load that corresponded to a rifle 'node' anyway. Besides, I can't use a powder throw and be near max. either...gives me the willies!

[44MAG#1]

Then Speer is crazy too. They list 58 gr with their 180 gr bullets.

[buckshotshoey]

Then Speer is crazy too. They list 58 gr with their 180 gr bullets.
I'm sure you know this, but bullet weight is only a small part of the physics on developing pressure. It very well could be accurate information.

[44MAG#1]

I'm sure you know this, but bullet weight is only a small part of the physics on developing pressure. It very well could be accurate information.

I started reloading between 17 and 18 years old and I am very, very close to 65. Yes I know it.
It was said "tongue in cheek".
But then again who knows as evidenced by the post that started this thread.

[buckshotshoey]

I started reloading between 17 and 18 years old and I am very, very close to 65. Yes I know it.
It was said "tongue in cheek".
But then again who knows as evidenced by the post that started this thread.

I thought so but wasn't sure. I started 27 years ago. Never had a problem with c.u.p. data....even at max loads. Something is going on somewhere.... to say the least.

[centershot]

Excellent work Larry, a very interesting and informative read! At times I have come across data that made me wonder how a company could possibly recommend it to the shooting public. Case in point, a load from Speer #8 for .38 special listing a rather healthy dose of #2400 powder, tested in a "K" frame. I worked up that load to a max load as listed, As I increased the charge weight accuracy improved until all I had was a jagged little hole at 50'. It was an interesting experiment and I'm sure pressure was over +P, but in the end I decided it was too much for my M-67 and discontinued use of it. To be fair, Speer noted that regular use would "loosen" the gun.

[44MAG#1]

"Excellent work Larry, a very interesting and informative read."

As I said in my first post on this subject pasted below.
No data from anyone should be taken as 100 percent reliable. From a Lab, individual or gunshop.
Can anyone prove that Hodgdons didn't get the results they listed with that test barrel, lot of components etc. at that time?
Maybe they did but maybe they didn't. Who knows.

Here is my first post.
"What I have taken out of all this is that NO loading data from ANY SOURCE can be counted on 100 PERCENT of the time.
This is something most veteran reloaders will probably know but are subject to forget at times.
This episode should be enough to reinforce the idea that relying 100 percent on any source of load data is bordering on the irresponsible even from a person that one perceives to know what they are talking about."

[buckshotshoey]

Can someone explain...in a short paragraph.... how the Oehler M43 detects actual chamber pressure?

Now I am by no means educated on this subject, but I did find this....

"I have worked with RSI on this unit's development and personally use it--and it is VERY neat. Unlike the old (and no longer available) Oehler M43 Ballistics Lab pressure unit which attempts to equate the pressures obtained in your gun to what would be obtained by firing that load in a SAAMI specification pressure barrel, PressureTrace gives the actual psi readings generated in your gun--a much more useful measurement. The Oehler readings are higher in most cases than the actual pressures generated in the gun. Oehler apparently included this quirk because their idea was to sell the units to commercial users who could then develop loading data traceable to SAAMI data for liability reasons".

Is it possible that the Oehler Data is off? And there has been recent reports of Winchester brass with loose primer pockets from the factory. On the other hand, the excess velocity is suspicious. Again, not doubting Larry's findings. I'm not adequately educated enough on measuring chamber pressure to do so. All I can do is ask questions.

[44MAG#1]

Strain gauge glued over the chamber. Which like anything man operated is subject to error.

[sqlbullet]

And not particularly well calibrated to be honest. A bunch of engineering goes into creating an accurate pressure barrel. A strain gauge on your gun can be calibrated and will provide more data points than a chronograph. It can be a guide in load development, but is still doesn't make your gun a lab grade pressure system.

[44MAG#1]

Larry Gibson is correct to post his findings on that load in his first post.
While I am cautious of all load data I am a believer in his findings on Hercules and now Alliant 2400 charges.
I use 21 gr 2400 as my upper load in the 44 Magnum.
Ocassionally we need to be reminded of these things.

[Larry Gibson]

Can someone explain...in a short paragraph.... how the Oehler M43 detects actual chamber pressure?

Now I am by no means educated on this subject, but I did find this....

"I have worked with RSI on this unit's development and personally use it--and it is VERY neat. Unlike the old (and no longer available) Oehler M43 Ballistics Lab pressure unit which attempts to equate the pressures obtained in your gun to what would be obtained by firing that load in a SAAMI specification pressure barrel, PressureTrace gives the actual psi readings generated in your gun--a much more useful measurement. The Oehler readings are higher in most cases than the actual pressures generated in the gun. Oehler apparently included this quirk because their idea was to sell the units to commercial users who could then develop loading data traceable to SAAMI data for liability reasons".

Is it possible that the Oehler Data is off? And there has been recent reports of Winchester brass with loose primer pockets from the factory. On the other hand, the excess velocity is suspicious. Again, not doubting Larry's findings. I'm not adequately educated enough on measuring chamber pressure to do so. All I can do is ask questions.

That statement, particularly that in bold, is not true at all. Obviously whoever wrote that is selling/pushing the RSI system. Dr. Oehler's information with the M43 specifically states the measured psi's are relative to the test firearm only. That is the same with pressure test barrels used by ammunition manufacturer's, both CUP and transducer. It is also true of any pressure measurements by the RSI system. They are relevant only to the test barrel unless a "correction factor" is used based on measurement of pressure with "reference ammunition" in that test barrel.

The pressures the manuals or other sources record and then publish using their their test barrels is most likely not the same pressure the same ammunition will generate in your rifle. Heck, the pressures generated do not even agree test barrel to test barrel. That's why "reference" ammunition is used as measurement standard to get a "correction factor". I also use "reference" ammunition to get a correction factor. I use a specific lot of factory ammunition that a technician provided me the pressure of when it was tested in their peizo-transducer. Thus the difference between the M43 measured psi and the factory measured psi is the "correction factor". That is how it is done to SAAMI test specifications.

BTW, the RSI system uses the same strain gauges measurements as the Oehler M43 does. The gauge, which is placed over the chamber (I place mine at the SAAMI designated measuring spot), measures the "stress" (electronic impulse) created in the gauge by the pressure placed on the barrel. The computer program then measures the level of stress over the time/pressure curve converting that to psi. Complete information is input into the program including the calibration of the gauge. Dr. Oehler did and extensive test installing on a CUP test rifle 2 separate peizo-transducers, a case mouth transducer, a Gauge for a M83 and a gauge for a M43. That is 6 different pressure measurements for each shot tested. The M83 (a commercial system which is extensively used in the munitions industry) and the M43 gave consistently comparable pressure measurements to the other methods including the CUP method. Keep in mind the CUP method will only measure the peak pressure and does not give any other pressure information.

Now for the doubting Thomas's please then explain why with the Hodgdon listed max load of 57.5 gr under the 178 gr bullet left 3 of the cases with swollen primer pockets which is a definite sign of excessive pressure in any load manual. The M43 masured that load's psi at 69,000+ which is excessive pressure for any 30-06 in any loading manual and would be certainly in line with swollen primer pockets.

Of course it's possible the measured data was off the 1st test. However, I checked everything out and had fired a test string of known ammunition performance prior to the 2nd test which gave psi's and velocity in the normal range of ES for that ammunition. Also the reduced loads of H4350 with the same 178 gr bullet produced lower psi's commensurate with the 1st tests results.

Additionally, I have five different bullets (178 ELD-X, Sierra 175 MK, Hornady 180 SPBT, Sierra 180 SPBT and Speer 180 SP) all loaded over 55.3 gr H4350 which is max Hornady #8 and #10 Manual's charge of H4350 for 175 - 180 gr bullets in the 30-06. The same W_W cases and Federal primers are used as in the previous tests. Also I will test the factory "reference" ammunition (Federal) and the same previous tested ammunition (LC M72 Match). All test strings are 10 shots (SAAMI test standard) unless pressures are excessive and I stop the test. I will test before the week is out, weather permitting, and then we shall see.

[44MAG#1]

I did not see where anyone doubted your findings. The meat of this thread is that NO loading data should be taken as 100 percent reliable from any source.
Would you say that I am wrong on my belief or not?
Many may look at a known source and then say it must be correct because ____________ fill in the blank says so in their data. Sometimes even the very seasoned reloader will do that.
We need to be careful and not do that.

[Larry Gibson]

I was referring to whomever buckshotshoey was quoting.

[44MAG#1]

Oh, my mistake. I really enjoyed your treatsie on 2400 powder.

[swheeler]

Larry, thanks for reporting your findings.:drinks:

[buckshotshoey]

I was referring to whomever buckshotshoey was quoting.
This is where I got it. I just dont have time to research multiple sources. Thanks for the explanation.

http://www.frfrogspad.com/ballisti.htm

[blackthorn]

This is where I got it. I just dont have time to research multiple sources. Thanks for the explanation.

http://www.frfrogspad.com/ballisti.htm

In my opinion----You do not have the time not to----Some injuries leave debilitating residuals!!

[buckshotshoey]

In my opinion----You do not have the time not to----Some injuries leave debilitating residuals!!
I meant multiple sources concerning the Oehler 43. I developed loads carefully. That's the reason I frequent this site.....even if it's only for a few minutes at a time.

[sqlbullet]

Great post Larry. I would just add one comment:


Keep in mind the CUP method will only measure the peak pressure and does not give any other pressure information.

The CUP method not only doesn't have any "other data", eg a pressure trace and curve, it doesn't actually tell you peak pressure either. It tells you the deformation effects of the average time/pressure and then that is correlated to a value that indicates whether to load is within spec.

A longer duration, lower pressure pulse can crush the cylinder as much as a shorter duration, higher pressure pulse. The copper pellet may have been exposed to very high pressure, but only extremely briefly. In this case CUP can give a false indication that a load if acceptable when in reality it has pressure spikes that should be a cause for concern. The PE method detects these spikes as well.

This is one of the reasons you saw certain load data amended down after PE testing became more common.

The Oehler M43, even with it's limitations, is a huge improvement over CUP, and is as accurate as is needed when used with calibrated pressure barrels. When using on your personal firearms, it will provide excellent reference data for load development.

[Larry Gibson]

"The Oehler M43, even with it's limitations, is a huge improvement over CUP, and is as accurate as is needed when used with calibrated pressure barrels. When using on your personal firearms, it will provide excellent reference data for load development."

Not quite correct; pressure barrels are not "calibrated". The Transducers are calibrated before installation in the pressure barrels.

Pressure barrels are then, after installation of a calibrated transducer, correlated to each other using "reference" ammunition provided by SAAMI only to members of SAAMI. Reference ammunition is simply a factory lot of ammunition known for its uniform internal ballistics. SAAMI then buys most of it, certifies it as "reference" ammunition and sells it to ammunition manufacturers who are members of SAAMI. By using a specific lot of factory ammunition that exhibits very uniform internal ballistics and knowing what psi it was tested at that lot of ammunition can then be used as "reference" ammunition. That is simply what SAAMI reference ammunition is and is how I check the correlation of my test results to what they should be. As you will see the Federal "reference" ammunition I use is very uniform.

With the M43 the gauges are calibrated by the manufacturer. That calibration data is entered into the program. I then use a "reference" ammunition to validate and correlate the installation and system. The M43 also goes through a check of the system and gauge before ach test. Also keep in mind even with SAAMI reference ammunition there will always be a variation of velocity and pressure shot to shot. There also will be a variation of velocity and pressure test to test. This is the same as you chronographing and identical load twice back to back and getting two different average velocities, SDs and ESs.

[Larry Gibson]

Well I completed the testing Thursday morning but there was a change to the load. My friend called me saying he needed to apologize because he had given me a bit of misinformation concerning the load that had enlarged the primer pockets in his 06, the subject of this thread. He said that the primer info he inadvertently gave me was not correct. He said he was not using the Federal Match 215s but was, instead, using Federal 210s. Was his bad he said as he uses the 215s I his long range 300 Winchester. He asked if the use of the 215 primer could account for the really high psi’s I measured. ……..

After I calmed down I told him he could put money on the identical load giving a higher psi with the 215 primers instead of the 210s. In fact it did (more later) to the tune of about 3,000 psi +/-. However, I told him that still doesn’t negate the fact his load of 57.5 gr H4350 under the 178 gr ELD-X bullet with 210 primers was enlarging the primer pockets. I further said that was an obvious indication of over pressure. My bad folks, I should have questioned why he was using a magnum level primer (the 215 Match primers are magnum primers) and probably would have discovered the error sooner. My apologies to all of you but let’s keep in mind that error doesn’t invalidate the previous test data.

So, I went down to my loading area and pulled 50 bullets, saved the powder, deprimed the 215s out of the cases, re-NS’d the 50 W-W cases, Re-primed the cases with Federal 210s, re-weighed the 55.3 charges of H4350 and then re-seated the 5 different bullets: 178 ELD-Xs, Sierra 175 MKs, Hornady 180 gr SPBTs, Sierra 180 gr SPBTs and 180 gr Speer SPs. With the correct loads and two different factory “reference, loads I departed at O dark thirty for the range, was set up at 0630 and was ready to test as soon as there was sufficient light for the Oehler Skyscreens of the set up M43 PBL to function. The temperature at the range when I began the test at 0645 was 65 degrees. The test loads and reference ammunition had been “stored’ at 70 degrees for 48 hours prior to the test.

I know some are not aware of SAAMI’s testing procedure and the use of “reference” ammunition. In this test rifle I have used a “lot” of a very uniform load of LC72 M72 Match ammunition. At 65 – 75 deg it invariably gives a 10 shot average of 53 to 55,000 psi and average velocities of 2550 to 2600 fps. To the uninitiated with little experience at pressure testing that may seem to be a large variation but in fact it isn’t. Also used is a test of a 10 shot test using the factory ammunition I use to “calibrate” (a misnomer BTW) the test rife. This was a lot of Federal 150 gr Power-Shok that the Federal technician had given me the tested psi (peizo-transducer) produces a uniform 58,500 to 59,900 psi when tested at 65 – 75 degrees.

205307

The first test was the M72 Match. As you can see not only by the data but by the time/pressure traces this lot is very uniform. The muzzle velocity (the M43 makes this correction from the “average”) was 2562 fps with an SD of 10 fps and an ES of 30 fps. That is very good. The Internals also are extremely good with an average psi of 53,500 and on 1,500 psi variation over 10 shots.

205308

Next test was with the Federal “reference” ammunition. Again from the internals we see excellent uniformity. Velocity was 2990 fps (box says 2910 fps) the SD at 10 fps and the ES at 27 fps. The average psi was 59,300 with an ES of 2,700 psi…..that also is very good.

Given the SAAMI MAP for the 30-06 is 60,000 psi (transducer/strain gauge) the Federal load is pretty much top end. I also find the 2990 fps (24” barrel) as top performance also. The measured psi of this test was within 300 psi of the Federal factory measured psi.

205309

Next tests were the 5 different bullets listed over 55.3 gr H4350 (the Hornady #8 and #10 Manuals max load for 175 – 180 gr bullets) in fire formed NS’d W-W match prepped case primed with Federal 210 primers. The AOL for all was 3.330”.

First was the Hornady 178 gr ELD-X. The muzzle velocity was 2758 fps with an SD of 9 and an ES of 27…..excellent. The average psi was 58,800 with 2,800 psi ES. All very well and about 3,000 psi less than the same load with the Fed 215 primers. This load is just under the SAAMI MAP for the 30-06 in this rifle. Obviously, even with the “softer”, 210 primers increasing this load another 2.3 gr would result in considerable over pressure and is why that load previously used expanded the primer pockets.

205310

[Larry Gibson]

The next test was with the Sierra 175 gr MK. The velocity was 2732 fps with an SD of 11 fps and an ES of 33 fps. The internals are getting a bit higher than the previous load with the average psi at 53,800 and 3,800 psi ES. That is pretty low psi considering the psi of the previous 178 gr bullet. But something else is amiss here. Look closely at the beginning of the time/pressure traces. Notice how uneven they are. Then go back and look at the M72 traces…..nice and smooth. The M72 is loaded with 4895 which ignites easier at lower psi. Note the Federal trace; see the little “step” in the beginning? That is the bullet leaving the case into the throat/leade which slightly increases case capacity and causes a slight drop or the leveling of psi then the psi picks up and the trace rises smoothly. That is also normal. But back to the traces of the 175 MK load…..those little spikes at the beginning of the trace are not “normal”…..it is telling us something and we shall soon see what.

205311

Next test is the Hornady 180 SPBT bullets. The internals are not that bad but then neither was accuracy. The velocity was 2712 fps with an SD of 18 fps and an ES of 59 fps. We see an increase in psi here with the average at 54,50 and an ES of 3,800 psi. Again we’re seeing those little spikes at the beginning of ignition.

205312

Next up was the Sierra 180 gr SPBT. This is where those little spikes catch up with us. Notice on the traces 2 through 6 the spikes are pretty pronounced…….the little pressure spikes really were trying to tell me something. Round #7 really got my attention to say the least. Some folks here in the past have questioned my ability to tell when an SEE was imminent……well folks, there it is. Note the delay in ignition (yes there was a very slight “click-bang”), the sharp spike in pressure with a slight stutter….that’s where the bullet was trying to stick in the leade. Fortunately for me and my rifle the bullet started moving and we see the slight drop off in psi and then the rise of psi in a normal fashion as the powder burned normally as the bullet kept moving. Not wanting to push my luck I did not fire the remaining 3 rounds of with the Sierra 180 SPBTs.

205313

Well that was certainly fun. A question I immediately wondered; was it really a pre-SEE or did something go wrong with the gauge or system? While the psi was higher than with the Hornady 180 SPBT it still was not excessive pressure at an average of 57,600. As we can also note the ES of the 180 Sierra test was considerably higher at 6,600 psi for the 7 shots. Then there was that slight “click-bang”………

Best to test ammunition of known performance so I let the barrel cool then shot 5 shots of the M72 Match. I omitted the 1st shot as its psi seemed high. However the next 3 shots psi’s were in the same higher end range for that ammunition. The 5th shot dropped back down to the previous psi range earlier tested indicating that the fouling from the H4350 had been overcome. It definitely appears the barrel was fouled from the previous test with H4350. Before testing each string I ran a couple wet patches (Hoppe’s #9) through the bore and then dry patches. The slightly higher psi’s of the first 4 shots is indicative of a fouled barrel with another powder. What is important here though is the smooth ignition and rises of the traces…..obviously nothing was wrong with the gauge or the system.

205314

I decided to test the 180 Speer SPs so I let the barrel cool, cleaned it and proceeded. The velocity was 2665 fps with an SD of 15 fps and an ES of 51 fps. The average PSI was 52,700 with an ES of 3,800. Note on the traces rounds 7 and 8 had small pressure spikes during ignition.

205315

At the end of this testing here is the conundrum using H4350 in the 30-06 with 175 to 180 gr bullets as I see it:

The Hodgdon #27 manual lists 57.5 gr as a maximum load with Sierra 180 gr SPBT bullets using WLR primers. By using the WLR primer instead of the Federal 210 as I used the ignition problem may not have been there as the WLR is a stronger primer. However, I measured the 55.3 gr load of H4350 at 57,600 psi. The stronger WLR primer might have bumped that up closer to the SAAMI MAP of 60,000 psi for the 30-06. We know that with a Federal 215 magnum primer that the 55.3 gr load is well above the SAAMI map. It was this 55.3 gr load that gave a near SEE.

The Speer #14 manual gives 58 gr H4350 as a max load with their various 180 gr bullets. They also used W-W cases with CCI 200 primers. Given the measured 52,700 psi of the 55.3 gr H4350 load with the Speer 180 SP it might be possible to use another 2.8 gr of H4350 and stay at or under the SAAMI MAP but my past experience doubts it.

The Hornady Manuals #8 and #10 give 55.3 gr H4350 as the max load with their 178 – 180 gr bullets. They used Hornady cases with Federal 210 primers. Given the Hornady cases have a bit less capacity than the W-W cases their psi’s probably would have been slightly higher. What became obvious in testing the 178 ELD-X and the Hornady 180 SPBT is that there can be a great disparity of pressure with an identical load using different bullet of similar weight, even of the same manufacturer. The 178 ELD-X psi was 58,800 and the 180 SPBTs was 54,500 psi. With the ELD-x bullets in Hornady cases with that load I’d guess the psi was very close to the SAAMI 60,000 psi MAP for the 30-06.

As to the near SEE; were I to use H4350 with 175 – 180 gr bullets in the 30-06 I would drop back to 53.5 gr as a starting load and consider 55.3 gr as a maximum load. I would most certainly use a magnum strength primer. There were no ignition anomalies with the use of the Federal 215 primers in the previous tests.

So where does that leave you, the reloader without the test equipment I have? My recommendation is to use another flavor of 4350 (IMR or Accurate). If you really need to use H4350 with 175 – 180 gr bullets then use a magnum primer with the start/max loads I suggest. Use a chronograph and with a 22 – 24” barrel stop when the velocity is 2700 fps – 2750 fps with a minimum of 7 shot tests.

[tazman]

This is absolutely wonderful data.
Thanks for taking the time and supplies to test this and for posting the results.

[JBinMN]

This is absolutely wonderful data.
Thanks for taking the time and supplies to test this and for posting the results.

Ditto! Many thanks!
:)

[whisler]

Add my thanks also. Very informative info!

[pjames32]

Thanks Larry for your efforts and the posts. Very interesting to those of us on the outside.

[buckshotshoey]

What is S.E.E.? Would it be Standard Error of Estimate?

[oldblinddog]

Secondary Explosive Effect

[buckshotshoey]

Larry.... have you been in contact with Hodgdon yet? They may try to brush you off but it is the best interest of all of us that you do so. Maybe at least they will retest.

[Larry Gibson]

Secondary Explosive Effect

Yes, it occurs when ignition of the powder is delayed, the bullet is driven into the leade, throat or bore and sticks there. The powder then ignites and burns but reaches excessive psi before the bullet can get moving again. The result is a kaboom. It is not a good thing to have happen.

[Larry Gibson]

Larry.... have you been in contact with Hodgdon yet? They may try to brush you off but it is the best interest of all of us that you do so. Maybe at least they will retest.

Not yet. Hodgdon specifically used the 180 Sierra SPBT bullet. They also used WLR primers which is a bit stronger in brisance than Federal 210s. I want to test again with WLR primers and the Sierra bullets but I have to get another box of bullets first as I've only a couple left from the box I used. With the bit stronger WLR primers I'm hoping the ignition problem will be solved If it is based on the previous tests with Federal magnum primers then the 55.3 gr charge should produce a higher psi than the 57,600 psi with the 210 primers. If so that would put the 55.3 gr load close to the SAAMI MAP meaning the 57.5 gr max load Hodgdon lists is still excessive. We shall see (hopefully not SEE).

Speer lists several of their 180 gr bullets with their max charge of 58 gr H4350. The 180 SP I tested ran 52,700 psi with 55.3 gr. So it is possible their max of 58 gr may still be at or under the SAAMI MAP. Further testing is also needed there. However, that raises the question; does that really apply to the other Speer 180 gr bullets? As we have seen from the Hornady manuals which also list several bullets under the same max charge of 55.3 gr that the 178 gr ELD-X bullet gave a higher psi than the Hornady 180 gr SPBT. If we increased the charge of H4350 so the psi of the Hornady 180 SPBT was the same as the ELD-X then the max charge would be greater.

[swheeler]

Getting to see pressure data from a documented SEE would be nice! Larry wear a helmet with full face shield, some body armor and maybe some arm and hand mace, make sure your strain gauge if functioning properly! :kidding:

[B R Shooter]

To me, published load data is a suggestion, a starting point. Load data is intentionally low so it would be safe in any production made gun, old or new (within reason). Factory chambers are made big to fit any commercial ammo. And production guns are, well, production guns.

This 30/06 Goodsteel put together is no longer a production gun. I would bet he did a bit of truing, and used a minimum SAAMI reamer, which is way better than a factory chamber. So to shoot loads and not "feel" or see any pressure signs until primer pockets open up is not surprising. It's common when using custom actions.

So yes, work up to loads, but you just may have a gun/chamber that will easily take more pressure than what a loading manual tells you.

[Larry Gibson]

B R Shooter

Load data these days by the reputable manual publishers who actually test the loads is not "intentionally low".....that is a myth. Tested data, especially that data tested via peizo-transducer method, for some time now is held to SAAMI specifications here in the US or to CIP specifications in Europe. There are some exceptions though where no specification for the cartridge is held by either SAAMI or CIP. There are also some cartridge data that is above SAAMI specifications such as the 8x57.

Factory ammunition is manufactured to a velocity specification (with a surprisingly large +/- fps range) with non canister lots of powder. The factories work up a load to meet that velocity specification while maintaining the pressures at or below the SAAMI MAP, the MPLM and the MPSM. If the load meeting the velocity specification for the cartridge/bullet, as developed in their pressure guns, are within those SAAMI specifications many of the factories then test in production rifles using the commercial Oehler M83 (the M43s big brother). If all proves well then the ammunition is loaded. Keep in mind the MAP, the MPLM and the MPSM may be under the SAAMI specification.

As an example; the SAAMI MAP for the 30-06 is 60,000 psi. It is an incorrect assumption to make that all factory loaded 30-06 ammunition generates 60,000 psi......it just isn't so but some does and some doesn't. The Federal 150 gr PS factory load I use as a "reference" is an example. It gives 2970 +/- fps out of the 24" test barrel. You can't get 2970 +/- fps out of a 30-06 with a 150 gr bullet w/o pressure. That's why the use of a chronograph is advised; if you push the expected velocity for any cartridge with any given bullet then you are pushing pressure.......it's basically that simple.

Keep in mind the manufacturer's test barrels are made to minimum SAAMI specifications and are also chambered to minimum SAAMI specifications. Obermeyer used to provide the most of the test barrels but I'm not sure about now. The Broughton barrel goodsteel put on my friends rifle (M700 action) was to minimal specs also. Yes goodsteel used a match chamber reamer and did his magic. The test barrel I use has a .300 bore and a .3081 groove diameter. I also used a match 30-06 reamer and chambered it to minimal headspace. Note the federal factory ammunition tested out in my test rifle within 300 psi of what that lot of ammunition tested in Federals test barrel with a peizo-transducer. That is well within test to test variation of the same lot of ammunition. Also note the velocity to pressure of that federal load; the pressure is just under the SAAMI MAP at that velocity.

"So yes, work up to loads, but you just may have a gun/chamber that will easily take more pressure than what a loading manual tells you
."

Based on my pressure testing of over 30 cartridges in numerous test barrels over the last 8 - 9 years I have to disagree 100+% with that statement. Unless you have the ability to actually measure pressures in that "gun/chamber" it is best to work up loads and then I can not emphasize more that you certainly do not exceed the data published by sources who have actually pressure test the data. Even then, as this thread discusses, there are discrepancies so one should not assume they are "underpowered" by any stretch of the imagination.

[B R Shooter]

I stand by my statement for these reasons. In shooting competition, loads are routinely shot that far exceeds the "load data" for the cartridge. There is nothing magical about these guns, other than the chambers fit the brass closely, the sizing dies match the chamber dimensions such that they do not overwork the brass. The actions are true, lapped surfaces and are strong. With these parameters, loads can be safely fired that exceed load data. Brass is easily reloaded 40-50 times as long the the brass doesn't reach its yield strength.

Published load data may fall in with SAAMI specs, but that is still a value that is set to work with production guns. And factory ammo falls within that as well. You wouldn't expect the published burn rates to be accurate would you? They are a guideline. Just looking at a number of burn rate charts will show you the same amount of differing info. The characteristics of how the powder burns doesn't follow the burn rates. Obviously there are different methods of testing burn rates.

My whole point here is, you shot a gun that did not exhibit the "normal" pressure signs, yet by virtue of the loose primer pockets, it did exceed the brass yield strength. Everything doesnt follow the narrative it should.

[Larry Gibson]

Perhaps you could give us an example of such competition loads that "far exceeds the "load data" for the cartridge" as published in a manual by a company that actually pressure tests?

That the gun initially used did not exhibit "normal" pressure signs is part of point to this thread. That my own test rifle did not exhibit any "normal" pressure signs either with a load that hit 69,000+ psi is also part of the point. "Normal pressure signs" are not always indicators of excessive pressure is the point. Additionally the point also is that there are apparent discrepancies in even the best of load manuals.

[B R Shooter]

I will, but I am at a match now and not at home. I will reference a 6PPC and a 6BR. In the mean time, if you would like to do a little research on your own, find a published load for a 6PPC using VV N133 and a 66 grain bullet. Or a 6BR using Varget with a 105/107 grain bullet.

You make my own point, you didn't see any pressure signs yet you say you exceeded the maximum pressure. Hmmmm. You have a good chamber, and and action that has good lug contact. The good chamber prevents the swollen case base since it is captured with little clearance. The good lug contact means both lugs are bearing evenly and solidly, which prevents the bolt setback upon firing. Measuring the case base doesn't show the expansion, and you didn't feel a hard bolt lift pulling the case.

I'll get back to you on the load data later Monday.

[Larry Gibson]

Have the load data you requested for the 6 PPC with 65 and 68 gr bullets. However, this thread is about published data using the components readily available over the counter. My friends rifle will chamber and safely shoot factory ammunition. Will your 6 PPC? Are your 66 gr bullets available over the counter? Is there published data for that bullet in manuals that pressure test their data? Do you know the SAAMI MAP for the 6 PPC? If not then how do you know you are exceeding "normal" pressures? Have you measured the pressure of your loads?

As to the 6 BR there is published data in manuals that test the pressure for 100 and 107 gr bullets using Varget. Again, what is the SAAMI MAP for the 6 BR? What is considered a "normal" max psi? how do you know you are exceeding "normal" max pressures. Have you measured the psi of your "excessive" pressure loads in your rifle?

Let me give you a hint; neither the 6 PPC or the 6 BR have a SAAMI established MAP. So if you would please advise what is the established "maximum normal pressure" for each and who has established it? My assumption would be since both cases use a SR primer I would peg a MAP for both at 62,000 psi because the 6 PPC is larger than the 5.56 case which has that as the military MAP. The 6 BR being based on the .308W head size with a SR primer pocket should also be capable of a MAP of 62,000 psi. Do your "excessive" pressure loads exceed 62,000 psi and if so, how do you know?

No, I do not make your point. You seem to be telling us it is okay to exceed the maximum pressure(?) for the 30-06 by 9,000 to 15,000+ psi just because the rifle "can take it".....so far. You are conveniently forgetting the swollen primer pockets which are a classic indication of excessive pressure but yet insinuate since there are no other "pressure" signs it is okay to continue shooting that load. You also are conveniently ignoring the fact I have measured the "excessive pressures" as posted in this thread and they exceeded any MAP for any cartridge in a M700 action. Yet you are telling us that's okay, just keep on shooting them....... I am saying just the opposite and am certainly am not "making your point".

Please understand, this thread is about 178 - 180 gr bullet in the 30-06 using H4350 exceeding the SAAMI MAP for the 30-06 cartridge. It is not about the 6 PPC or the 6 BR using VV 133 or Varget. If you want to continue an esoteric discussion on your 6 PPC and your 6 BR then kindly start another thread.

Enjoy the match, shoot well.

[B R Shooter]

I have been trying to point out that certain guns can and do shoot loads that exceed published maximum loads. Some can't.

[M-Tecs]

For the long range competitors accuracy is paramount but past 600 yards wind drift becomes a large component of accuracy. Very common to develop max doing based on whatever acceptable primer pocket life you wanted. In the early days of 80 grains 22 cal bullets in Service Rifles the AMU used a load termed "V-8". It started life as a primed and crimped LC unfired brass. What the load they used would generally stretched the pockets of the virgin crimped cases to the point they were not useable. For the AMU one firing was acceptable case life. I do not know if they had any rifle based issues from this load.

With the new bullets and powders the Palma shooter don't have to push the limits has much as they used too. It used to be fairly common for cases to lose the primer pockets after 3 firings.

[Larry Gibson]

I have been trying to point out that certain guns can and do shoot loads that exceed published maximum loads. Some can't.

That is correct; the 8x57 as previously mentioned is one as are the 45 Colt, 45-70 and the 223 Rem (when loaded to 5.56 pressures) are just a few to mention along with the 30-06. However, that is not to say they are, or at least they shouldn't be, loaded to excessive pressures.

Since we're discussing the 30-06 here lets use that as an example if we are to follow your previous advice. The load of 56.5 gr H4350 under the 178 VLD yielded 69,100 psi average at 65 degrees. So let's assume we continued to shoot that load considering that average velocity as the MAP. SAAMI gives a MPSM (Maximum Probable Sample Mean) MPSM defined by SAAMI as; "the maximum expected average pressure that may be observed in the testing of product subsequent to its manufacture and is not intended for use as a loading control point." The MPSM is usually measured under extremes of temperature range, again after production. The SAAMI MAP for the 30-06 is 60,000 psi and the MPSM is 63,800 psi, some 3,800 psi higher than the MAP.

So let's say we load up and continue to shoot that 56.5 gr load at 69,100 psi at 65 degrees, Yeah we have a few primer pockets expand every firing but no big deal, the rifle can take it..... and then my friend travels down here to Arizona to shoot and it's 100 degrees and the psi rises that additional 3,800 psi to now a MAP of 72,900 psi.........What do we think will happen if we continue shooting loads close to proof level.......probably not something good and something I do not want to find out...........

Now, if you look at SAAMI's MAPs, MPLMs and MPSMs for magnum level cartridge that are also used in the M700 action then we see MAPs of 64 - 65,000 psi's and MPSMs of 68-69,000 psi. So how is it we can shoot those at higher pressure. The weak link in the action/barrel/cartridge is the cartridge case. The barrel and actions can take more pressure than the brass case. A magnum case will have more brass around and supporting the primer pocket than will a 30-06 size case. Thus it can take a pit more pressure before the primer pockets expand.

As you mentioned the SAAMI 30-06 specs keep some cartridges safe for use in older actions such as the LSN M1903s and M95 Winchester lever actions. However, in quality bolt actions such as the M700 there is no reason, in my opinion, that the 30-06 can not be loaded to the same MAP level as the .308W, 62,000 psi. Now I can measure that but 99.99999999999999999999% of the reloaders out there can not. That included my friend. He was going by Hodgdon's data for the 180 gr bullet with H4350 for use with the ELD-X 178 gr bullet. Hodgdon's data for the 180 gr bullet has proven to be excessive (exceeding even the MPSM for the .308W and actually being proof level pressures) with the 178 gr ELD-x bullet. That the data for a 180 gr bullet in the 30-06, assumed by reloaders every where to be useable with a lighter weight bullet, is in error is the topic of this thread.

[JBinMN]

Larry Gibson,

I am thinking that my signature line below applies here in this topic for ya.
;)

Some folks say.. "For every rule , there is an exception."...

Other might say, " for every exception there is another exception".

Lester Ackerman, ( & I) would say,
"Here are the rules...( load manuals), Do as ya like, but don't give me any grief if you want to break those rules. You chose to make the mistakes... You suffer the consequences.... Not me..."

Here you are, being kind in sharing your data & experiences with how those manuals may be mistaken, & giving folks a "Heads Up!" , that they should think about what they are doing... ( Your gate.)

If others do not wish to pay attention to your data & experience(s) and heed them. (Swinging on the hinges)

Then, they can go develop their own data & experiences & not be concerned with yours that you are being kind in sharing...
;)

[ Perhaps make a topic of their own where they can go into THEIR data & experiences... and THEIR "gate")

See the signature below... It fits, IMO.

And Thanks again for your efforts! I , for one, am paying attention.
:)

[44MAG#1]

Yours: Lester Ackerman, ( & I) would say,
"Here are the rules...( load manuals), Do as ya like, but don't give me any grief if you want to break those rules. You chose to make the mistakes... You suffer the consequences.... Not me..."

My Reply: Evidentally Load manuals are NOT the rules as evidenced by Mr Gibsons first post

Yours: Here you are, being kind in sharing your data & experiences with how those manuals may be mistaken, & giving folks a "Heads Up!" , that they should think about what they are doing... ( Your gate.)

My Reply: You said it "may be mistaken" but who is to say 100 percent that they didnt get thoes results at that time with the combinations of components and lots of components? Can anyone be CERTAIN? Do you KNOW absolutely that with the lots of components they used that Hodgdons results are in error? Has Mr Gibson tested every lot of H4350, every lot of Sierra SPBT 180 gr bullets and every lot of WLRP?

Yours: If others do not wish to pay attention to your data & experience(s) and heed them. (Swinging on the hinges)

Then, they can go develop their own data & experiences & not be concerned with yours that you are being kind in sharing...
;)

My Reply: Certainly Mr Gibson was kind in sharing his experiences I am for one glad he confirmed what I already know and what most experienced reloaders know and that is there is NO load data from anyone including Mr Gibson is 100 percent reliable across the board. Sometimes we can forget about that fact. Ask him if you dont believe it. I dont think for one minute that he thinks he is infallible.

Yours: [ Perhaps make a topic of their own where they can go into THEIR data & experiences... and THEIR "gate")

My Reply: Are you saying that one developing their own data is impossible? It can be done by careful experimenting watching for the CORRECT signs. Tell that to Someone like JD Jones or Gary Reeder.

Yours: See the signature below... It fits, IMO.

And Thanks again for your efforts! I , for one, am paying attention.
:)[/QUOTE]

My Reply: I am paying attention too as I hope everyone is and that is not to take ANYONES data as 100 percent reliable.
All Mr Gibson has done is reminded us of that, nothing more nothing less. But his reminding us of that was important. Dont turn it into something it isnt.

[JBinMN]

My Reply: I am paying attention too as I hope everyone is and that is not to take ANYONES data as 100 percent reliable.
All Mr Gibson has done is reminded us of that, nothing more nothing less. But his reminding us of that was important. Dont turn it into something it isnt.

I am certainly not.

I saw another member dispute Mr. Gibsons findings. With -0- proof. No pics, no data, no corroboration, etc.

No data, just hearsay that the other member had gone over the load manuals & demonstrated no pressure issues.

"MY" point was that "I" would not worry about the other members posts if I were Mr. Gibson, as they were just someone swinging on Mr. Gibsons gate hinges here in this topic, & not offering up some data/evidence on his own.

If ya don't understand that... Well, I can understand someone not understanding me. Sometimes I am not as clear as I would like to be when typing. Spoken words is better sometimes, for me anyway..


Regardless, that other poster might want to either prove his claims with some some sort of data or evidence, or, quit "swinging on Mr. Gibsons hinges"...

That understandable?

[JBinMN]

BTW.. I am gonna try to address your post as ya wrote it. It might take me some time as I have to figure out wher to put the answers, but the post before this one sums up my thoughts pretty well.

[JBinMN]

Yours: Lester Ackerman, ( & I) would say,
"Here are the rules...( load manuals), Do as ya like, but don't give me any grief if you want to break those rules. You chose to make the mistakes... You suffer the consequences.... Not me..."

Meaning that most everyone uses the load manuals a guidelines to load/reload. If someone wants to do other than those guidelines it is on them, not anyone else.

My Reply: Evidentally Load manuals are NOT the rules as evidenced by Mr Gibsons first post

Obviously, which is why I mentioned load manuals & then how Mr. Gibson is saying they are not always correct. See what I bolded below from my original post...

Yours: Here you are, being kind in sharing your data & experiences with how those manuals may be mistaken, & giving folks a "Heads Up!" , that they should think about what they are doing... ( Your gate.)

My Reply: You said it "may be mistaken" but who is to say 100 percent that they didnt get thoes results at that time with the combinations of components and lots of components? Can anyone be CERTAIN? Do you KNOW absolutely that with the lots of components they used that Hodgdons results are in error? Has Mr Gibson tested every lot of H4350, every lot of Sierra SPBT 180 gr bullets and every lot of WLRP?

Irrelevant. I am posting in Mr. Gidsons topic about Mr Gibsons research that is IN this topic. Not other folks doings..


Yours: If others do not wish to pay attention to your data & experience(s) and heed them. (Swinging on the hinges)

Then, they can go develop their own data & experiences & not be concerned with yours that you are being kind in sharing...
;)

My Reply: Certainly Mr Gibson was kind in sharing his experiences I am for one glad he confirmed what I already know and what most experienced reloaders know and that is there is NO load data from anyone including Mr Gibson is 100 percent reliable across the board. Sometimes we can forget about that fact. Ask him if you dont believe it. I dont think for one minute that he thinks he is infallible.

Pure inference. Even a "logical fallacy" perhaps. Definitely a different interpretation of what I was trying to say. Some call it, "putting words into my mouth.". I made no attempt to place Mr Gibson on a pedastal, but only to recognize his efforts.


Yours: [ Perhaps make a topic of their own where they can go into THEIR data & experiences... and THEIR "gate")

My Reply: Are you saying that one developing their own data is impossible? It can be done by careful experimenting watching for the CORRECT signs. Tell that to Someone like JD Jones or Gary Reeder.

Once again, inferring that I am holding Mr. Gibson as higher in his research than anyone else. Not so. I was only recognisinf Mr. Gibson for his efforts & that anyone else who differs with him should do their own research to show folks that either Mr. Gibson is incorrect, verify Mr. Gibsons research or to add another "exception" to the load manuals data.

Yours: See the signature below... It fits, IMO.

It did & still does, IMO.

And Thanks again for your efforts! I , for one, am paying attention.
:)
snip [/QUOTE]

[oldblinddog]

https://en.m.wikipedia.org/wiki/Data_sharing
Data sharing is the practice of making data used for scholarly research available to other investigators. Replication has a long history in science. The motto of The Royal Society is 'Nullius in verba', translated "Take no man's word for it."[1] Many funding agencies, institutions, and publication venues have policies regarding data sharing because transparency and openness are considered by many to be part of the scientific method.[2]

https://en.m.wikipedia.org/wiki/Scientific_method
The scientific method also includes other components required even when all the iterations of the steps above have been completed:[41]

Replication
If an experiment cannot be repeated to produce the same results, this implies that the original results might have been in error. As a result, it is common for a single experiment to be performed multiple times, especially when there are uncontrolled variables or other indications of experimental error. For significant or surprising results, other scientists may also attempt to replicate the results for themselves, especially if those results would be important to their own work.[42]

External review
The process of peer review involves evaluation of the experiment by experts, who typically give their opinions anonymously. Some journals request that the experimenter provide lists of possible peer reviewers, especially if the field is highly specialized. Peer review does not certify correctness of the results, only that, in the opinion of the reviewer, the experiments themselves were sound (based on the description supplied by the experimenter). If the work passes peer review, which occasionally may require new experiments requested by the reviewers, it will be published in a peer-reviewed scientific journal. The specific journal that publishes the results indicates the perceived quality of the work.[43]

Data recording and sharing
Scientists typically are careful in recording their data, a requirement promoted by Ludwik Fleck (1896–1961) and others.[44] Though not typically required, they might be requested to supply this data to other scientists who wish to replicate their original results (or parts of their original results), extending to the sharing of any experimental samples that may be difficult to obtain.[45]

Larry is sharing data. Anyone that wants to replicate his testing should do so before making comments. Conjecture and opinion have no place here.

[Larry Gibson]

"Certainly Mr Gibson was kind in sharing his experiences I am for one glad he confirmed what I already know and what most experienced reloaders know and that is there is NO load data from anyone including Mr Gibson is 100 percent reliable across the board. Sometimes we can forget about that fact. Ask him if you dont believe it. I dont think for one minute that he thinks he is infallible."

No I certainly don't think I'm infallible......that's why I test and retest. I also have learned to not hesitate to change my way of thinking based on facts presented, especially when those facts are scientifically based on proper testing procedure, even when they contradict long held beliefs based on suppositions. I don't hesitate to do that even if they contradict suppositions made by popular big name writers/reloaders of today and yesteryear. The test equipment we have today is much more reliable than the test equipment they had even 20 years ago. There are many that draw conclusion based on insufficient test and beliefs in unproven theories (most of which are myths) data not only on this and other forums but also big name writers in magazines, books and on U-tube. I am not one of those.

We all, at least those who have been reloading for a while, used the old methods of case expansion, bolt lift, primer flattening, etc. to "develop loads". Most staying with in the manuals data. Some did not. Those methods have been proven modern pressure testing to be grossly in error which is why many loads are lower in newer manuals. It's also why most all of the loads in P.O. Ackley's old books are most often grossly over pressure. With modern pressure measuring methods we have a much more complete picture of the time/pressure curve and the much more data. In the 30-06 of this topic the top listed load for the 180 gr Sierra SPBT was grossly over pressure with the 178 gr bullet. Not only over pressure by measurement but also by the fact the primer pockets expanded to no longer hold primers. We also know by pressure measurement and lack of primer pocket expansion that the max load of H4350 (55.3 gr) listed in the Hornady manual for 178 - 180 gr bullets was not over pressure. We also know by measurement and a near SEE that standard strength Federal 210 primers do not properly ignite H4350. We know by measurement that Federal 215 Magnum primers are sufficient to ignite H4350 in the 30-06 properly Those are facts.

The key is in proper testing. As you can note in this thread the parameters of the tests change as we gained more knowledge. That is as it should be. When the tests continue to reach the same basic conclusion such as in this case; the data in Hodgdon's #27 manual may be error regarding 180 gr bullets using H4350 in the 30-06. Continual testing points to that. We know the definition of insanity; doing the same thing over and over expecting different results........

No, I have not tested every combination. The testing continues. However, Lots of powder are made within narrow specifications of burning rate which is why the manuals do not delineate the specific lots of individual powders tested. Reloaders assume any lot of a powder should fall with in the start and maximum charges listed in the manuals. It is possible Hodgdon did find their max load listed of 57.5 gr with H4350 under the Sierra 180 SPBT to be with in SAAMI spec. It's also possible Speer found the same thing with one of their 180 gr bullets under 58 gr H4350. What I have found is that both Hodgdon and Speer data will give excessive pressures with 178 gr bullets and probably (that's where the testing is still ongoing) with some 180 gr bullets even with the same primers.

Until the testing is conclusive I am not about to go to Hodgdon and Speer telling them the sky is falling.......I will continue to test until there is not doubt.

[swheeler]

:popcorn:

[buckshotshoey]

Larry.... I tried reading through the extensive information you have posted and didn't see the answer to this question......

You referenced the information from the Hodgdon 27 manual. Quote from your first post.....

"so I opened up my Hodgdon #27 manual and turned to the data for the 30-06 with 180 gr bullets. The #27 manual lists the max load for 180 gr bullets using H4350 at 57.5 gr. That is with a C.U.P. of 49,200."

Which 180 gr bullet is this info referencing to? Have you tested that specific 180gr bullet and the Hodgdon 4350 to verify Hodgdon's findings in the #27 manual?

[Larry Gibson]

Post #51 has the test data. The #27 Hodgdon manual uses the Sierra 180 SPBT. Note in the test results the near SEE. I used a Federal 210 primer in my test. I am going to retest with WLR primer which is the primer Hodgdon used.

[B R Shooter]

Mr. Gibson, as I said earlier, here is the published load data for the 6PPC and 6BR.

For the PPC, the most common powder used by far is VV N133. The VV 2-01 manual shows a maximum charge using a Euber 68 grain bullet and N133, is 28.1 grains. Most shooters START higher than that. A maximum to some is 30.8 grains. I have heard of velocities that defy logic, but they do it. I personally wouldn't get close the that, but many do with regularity.

For the 6BR and Varget powder, the Hodgdon 27 manual for a 100 grain bullet, is 28.0 grains. Most use a 105-107 grain bullet, and a 30.0 grain load is common with some going higher than that.

I used to shoot a 308 quite a bit, but that was a long time ago and can't remember the load. It was over published data.

Let me say again, this is done with custom actions and match chambers. And the sizing dies are matched to the chambers, so the brass doesn't suffer. The run of the mill, off the shelf gun, can't handle it.

All the acronyms in the world used to explain why this can't be done, doesn't work.

[Larry Gibson]

B R Shooter

All that load data is fine but what, pray tell, is the accepted "normal" maximum pressure for either cartridge? You don't know because there isn't one as neither cartridge is a standardized SAAMI or CIP cartridge. Exceeding an establish measured maximum pressure is the thrust of this thread. Because you use higher loads than published for those two non standardized cartridges does not mean you are using excessive pressures in either cartridge. You can not tell us what is an established MAP for published loads of either cartridge nor can you tell us what the pressures of your own loads are or that.....can you?

What I'm saying here is the highest established MAP (SAAMI or CIP) for any cartridge with a 30-06 head sized cartridge is 65,000 psi in modern actions. That includes the 270 Win, .308W, 243 Win, 260 Rem, 25-06, 22-250, etc. It also includes the 6 BR. The 6 PPC using a SR primer has sufficient case support around the primer to support 62,000psi also as does the smaller 5.56 cartridge. Thus any average psi over that 62,000 psi measured under standard test conditions should be considered "excessive" pressure.

Now, can you show us that either of the loads you use in the 6 PPC or the 6 BR have a measured psi in excess of 62,000 psi? If not, then regardless that your loads exceed published data, if they do not exceed 60 to 62,000 psi then they do not have "excessive" pressure for either the cartridges or for the modern actions they are used in.

The topic of this thread, once again, is a 30-06 load less than published max loads which exceeded 62,000 psi by a measured considerable margin and which demonstrated excessive pressure by expanding primer pockets.

[B R Shooter]

I am done arguing. I understand what the points are you are trying to make. My point all along is simply that published data, isn't necessarily gospel. Just because it is written down, doesn't make it right. Let your gun tell you what maximum is, it varies.

[44MAG#1]

"My point all along is simply that published data, isn't necessarily gospel. Just because it is written down, doesn't make it right. Let your gun tell you what maximum is, it varies."

That is the point I made early on. This whole thread wasn't about anything else but load data from any source is not concrete, positive, non negotiable, holy writ, 100 percent accurate, undeniable, factual, spot on, unquestionable, non variable and whole list of other things it isn't.
I always consult more that one source of data both old and new to newest I can find. Then I make a determination as to where I start and stop.
C-A-U-T-I-O-N is the word.
But Mr Gibson being an owner of a personal ballistic lab and having a mind for data is now supplying us with more data. Which, with him being an honest man will readily tell you his data is just more data that is not concrete, positive, non negotiable, holy writ, 100 percent accurate, undeniable, factual, spot on, unquestionable, non variable, and a whole list of other things it isn't.
Let him run the same test two years from now with entirely different "lots" of the same components and see if it is.
I don't think for one minute he will do the thing on our legs and try to tell us it's raining. Unless my opinion of him is badly flawed.
Don't make more out of this thread than what it was. Just a warning and nothing else.

[Digital Dan]

Let your gun tell you what maximum is, it varies.

BR Shooter, your gun is an idiot and prone to not telling anybody anything until the news is really depressing.

I suggest to the rest that experienced shooter/loaders realize that every gun and load is a sea of variables that skew off the course from published data. Brass is a variable, primers/powder/bullets/bore condition etc. etc ad nauseum are all their own merry carnival. A prudent and disciplined mind will resist the notion that it is special, blessed, immune to such mundane things as engineering principals, standard deviations, MAP and so forth. You mommy gave you but one face, take care of it.

Larry, I appreciate your effort on this, thank you for the investigation and report.

Dan

[swheeler]

"What I'm saying here is the highest established MAP (SAAMI or CIP) for any cartridge with a 30-06 head sized cartridge is 62,000 psi in modern actions."
Not quite correct, ie 6mm Remington SAAMI MAP 65,000 PSI, 25-06 63,000 those both are 06 head size. The whole point is loading manuals are just guidelines used to establish a maximum load in your rifle with your components. A seasoned hand loader learns to watch for signs of excess pressure and adjust accordingly, signs like sticky extraction, very sharp transition from case body to pressure ring at web which is visible even on a case fired in min spec chamber(your case) and more so on a production chamber, brass extruded into bolt face and especially LOOSE primer pockets after only a couple firings. Reduce down 5% and you will be safe! Fire these loads for velocity and accurracy, if they don't meet your needs change components until it does. Science is important in handloading but you've just got to have the "street smarts" to keep your eyes and fingers intact. The data Hodgdon published could very well be safe(at or below SAAMI MAP) in their barrel and EXACT components they used. Correct me if I'm wrong, but isn't the criteria for canister grade powders +- 5% of average burn speed per lot to lot variation?:2 drunk buddies:

[Digital Dan]

MAP stands for maximum average pressure. What is the max peak pressure for the cartridges?

[44MAG#1]

"MAP stands for maximum average pressure. What is the max peak pressure for the cartridges?"

Who cares? That not really the meat of this topic. This can be discussed, cussed, argued, debated, whined about, even cried about but the meat of this thread is no load date whether it is SAMMI set, wildcatter set, or crystal ball set or seasoned home reloader set is not 100 percent reliable.
Real meat of this thread is: USE CAUTION WHEN WORKING UP LOADS IN ANY FIREARM using any source of written, vocal, or assumed data from any source including people on here or from the labs.

[Digital Dan]

Well, I care. I suggest we are on the same side of the discussion though it might not be obvious.

[44MAG#1]

"Well, I care. I suggest we are on the same side of the discussion though it might not be obvious."

If you will look on SAAMI specs site you will see most standard case head sizes will run around 6.2 to 6.4 percent MAX ALLOWABLE PRESSURE over MAP. Not say that is true for all cartridges (Mr Gibson take note as I am sure I am wrong but I looked at several cartridges) because remember NOTHING is concrete fact.

[Digital Dan]

44Mag#1, I'm not looking for argument here and in one sense I agree with your thoughts though I look at it from a perspective that might be different than your own.

On the matter of pressure metrics that I raised previously, It was a rhetorical question to some degree. You refer to percentages which are not unreasonable, I refer to published specs. SAAMI refers to MAP, MPLM (max probable lot mean) and MPSM (max probable sample mean) in establishing their data. They do it with crusher or transducer data sometimes both for each of the cartridges for which they set standards.

The point I was trying to make is the range of variation between the three data references are rather narrow, and as Larry has pointed out, and done so well in my opinion, is that small things matter. A point I would make is that conventional references used by some handloaders such as a shiny belt on a fired cartridge, sticky bolts, loose primer pockets etc. are more than likely far beyond pressure levels required to present such evidence and reliance upon such things is risky to say the least.

A couple of experiences from days gone by if I might, both in the general range of 20 years ago.

#1: I had a Ruger #1 in .22 Hornet that did not shoot particularly well and in the course of conversation with a very qualified 'smith he suggested a K-Hornet conversion. The deal was done, and in the process I picked up my first bottle of Lil Gun powder. The "internet" gurus suggested that 13.0 grains was a good load for the Hornet and I figured that if good for the Goose.... But being a bit cautious I called Hodgdon and spoke with one of their techs, for there was NO data available at that time for the K. He was quite clear that I could not put enough L.G. in a Hornet or K-Hornet case to cause pressure problems and there ya go, right from the horse's mouth.

Now the funny thing is that I could not get 13 grains of LG in a Hornet case. Best I could do with an unfired case was about 12.5 and that became my fireform load. It worked quite well, all things considered. Went to the line, did a FF on 50 cases and then set about reloading them. Off to the range a few days later, set up on the bags at 100 yards and popped off 3 rounds. Shazaam! 1/2" groups right out of the gate. Next series was fired over a Chrony just for giggles. 13.0 gr L.G. filled the case to the shoulder and I had loaded 40 gr Nosler BTs. Group of 5 went into about 3/4" with an average velocity of 3360 fps. At that point I was wondering why anyone would want a .222 or .223 shooter. Extraction was normal, the cases had no tell tale ring at the web, life was good. Right? 3 load cycles later with that brass and the primers fell out of the cases on extraction w/o shiny rings at the web. So much for expert techs and web wisdom. I settled back to 12.5 grains of powder and 3,000 fps avg for that same bullet and called it good. No issues since.

#2: A friend and fellow employee had picked up what was then a new .300 Weatherby and asked if I'd help him get started with it and perhaps load some ammo. Since he wanted to follow up with handloading as well I agreed. Bullet of his choice, brass was once fired Weatherby stock. The load data was abundant and by odd chance I had some which matched components with exception of the rifle. I loaded a box for him and passed them along with very explicit instructions to the point that if he experienced any abnormality in bolt lift or extraction that he was to stop shooting and confer with me prior to further shooting.

The gun and shooter preformed remarkably well insofar as precision went, typically grouping 3 shots in less than an inch @ 100 yards. Over the course of several weeks we increased the load in small increments. My normal path on such things is no more than 1 grain on round 2 and at the mid point between suggested starting loads and max loads I revert to .5 grain increments. At the point where we had spanned half of that gap or about 2.5-3 grains of charge increase he returned the brass after a range session, laughing about the fact they had to beat on the bolt with a piece of 2x4 to open the action. He and his shooting buddy thought it vastly amusing. I opened the box and all cases were empty. Asked him if it was the last round that did this and he smiled, said "No, they all were like that." I handed the brass back to him and wished him luck. The load in question was 3 grains under load manual maximum charge for that specific bullet/primer/powder/COAL combination.

I'm not an engineer, but tend to think like one most days due to frequent affiliation with such people, and the fact that I spent several years examining the pieces of aircraft accidents and figuring out what went wrong. Just like handloading mishaps, most aircraft crash due to pilot error. Those caused by design or mechanical malfunction are rare, albeit interesting, once the blood has dried and the smell dissipates.

My point is pretty much your own. Caution is appropriate and there is little reward for heroics, unless one happens to be an ER surgeon. Facts are where you find them and conventionally accepted clues in this game are far from reliable.

[Larry Gibson]

MAP stands for maximum average pressure. What is the max peak pressure for the cartridges?

SAAMI uses a statistical method to determine that based on the Extreme Variation derived from the knowledge of the population standard deviation of any lot of ammunition using the Relative Range Tables (Biometrika Tables for Statisticians) A Maximum EV is calculated from the MPSM for the cartridge. The MPSM for the 30-06 is 63,800 psi, after that your guess is as good as mine........

All that is a little above my pay grade so I prefer to go with the SAAMI MAP for most cartridges. I do, in some cases given a modern action, new brass and actually measuring the psi, load to the 62 - 65,000 psi range with certain cartridges of '06 head size. The SAAMI MAPs are derived by putting the pressure level two standard errors below the MPLM pressure in order to assure a 97.5% probability that the MPLM is not exceeded. To me that seems a good safe fudge factor.

[Larry Gibson]

Digital Dan

Your 12.5 gr of LG for a FF load for your K-Hornet is my standard Hornet load under a Hornady 45 gr Hornet bullet. The measured psi of that load is 20,000. Winchester 45 gr factory measures 24,900 psi.

[Larry Gibson]

Completed the 3rd test with no real change in the result; The max load of H4350 under 180 gr bullets in the 30-06 cartridge as listed in Hodsdon’s #27 Data Manual and Speer’s Reloading Manual #14 give pressures in excess of the SAAMI MAP for the 30-06 cartridge.
I finished testing this morning at the same range. The M43 Oehler was set up as usual and the same test rifle was used. Temperature was a mild 65 degrees with no wind. No problems were encountered during the testing. The barrel was allowed to cool and was cleaned between tests. Tests include the fouler shot which many times increases the ES and SD slightly. However, with this test barrel the results are usually not skewed enough to denigrate the results.

After set up and a systems check of the M43 I shot a five shot “reference ammunition” test using the same very uniform lot of M72 Match ammunition as previously used. The MAP was 54,400 psi with a velocity of 2540 fps; exactly within the +/- range for that lot of ammunition. The time/pressure curves (traces) were very smooth giving no indication of any abnormality. Had I deleted the fouler shot the velocity would have been 2550 fps……exactly what the velocity for this lot (loaded for M1s to equal the ballistics of M118) is supposed to be.

205657

With the system, including test rifle, measuring velocity/pressures normally and validated the test continued.

The Hodgdon #27 Data Manual lists their test parameter for the 30-06 cartridge as;

Cases; Winchester
Trim; 2.484
Barrel; 24”
Twist; 10”
Primer; Winchester LR

The test rifle used has a 24” barrel with a 10” twist. The Winchester cases used were trimmed to 2.484”. The cases were primed with Winchester WLR primers.

The data lists the bullet used as a Sierra 180 SPBT loaded to a cartridge OAL of 3.300”. The test loads were loaded with Sierra 180 gr SPBTs with a Cartridge AOL of 3.300”.

The load data for H4350 shows a maximum load of 57.5 gr for 2798 fps at 49,300 C.U.P.

I unfortunately at this stage of testing the lb of H4350 I had was running short. Thus I decided to conduct my usual initial pressure/velocity test. This is to load 3 shots of each load working up to a listed maximum charge in .5 gr increments. This gives a quick look with a certain cartridge/bullet/powder combination at what the potential velocity would be at a maximum MAP. Thus I loaded 4 rounds of 55.3 (to exclude the fouler) and then 3 rounds each of 55.8 gr, 56.3 gr, 56.8 grand 57.2 gr (just .3 gr under the manual’s 57.5 gr maximum charge). It should be noted the first test of this Hodgdon load I used Federal 210 primers and had ignition problems that gave signs of potential SEE. In this test it should be noted the ignition problems seemed to be negated with the more powerful WLR primer. The pressures are also notably higher.

55.3 gr gave us 2741 fps at 58,900 psi. The traces are smooth and the “rise” figures are also uniform.

205658

55.8 gr gave us 2785 fps at 61,700 fps. At this point this load is 2.2 gr under the maximum load listed in the #27 Data Manual and is already over the SAAMI MAP for the 30-06. The velocity (corrected to the Muzzle) is just short of the 2798 fps listed in the manual. Keep in mind given the same rifle/cartridge/load with an increase in velocity by increasing the powder charge there will be an increase in pressure. Here we are 2.2 gr less than the charge listed in the manual and are getting basically the same velocity. Thus based on the assumption Hodgdon is a member of SAAMI and adheres to SAAMI specifications, given the C.U.P. listed in the manual) there does indeed seem to be something not right with the data concerning H4350 in the 30-06 with 180 gr bullets.

205659

Though at the MAP of the 30-06 I decided to continue the test…..within reason anyway.

56.3 gr gave us 2814 fps at 63,400 psi.

205660

56.8 gr gave us 2844 fps at 65,400 psi. Now if we really wanted to push things and load to the maximum MAP of any ’06 sized case head (65,000) then probably 56.5 gr would be the maximum charge with this bullet.

205661

57.3 gr gave us 2874 fps at 68,100 psi with one shot hitting 71,400 psi. Still .2 gr below the manuals maximum charge this is clearly “excessive”. The primers were flattened and slightly cratered.

205662

All of this is useless some would have us believe. Let the gun tell us? The rifle (gun) told me nothing. There was no hard bolt lift. There was nothing amiss with the functioning of the rifle. Let the cases tell us? The cases extracted normally. There was no indication of excessive case head or expansion ring expansion. The primers were not excessively flattened although at 57.3 gr there was a bit more flattening and a small bit of cratering. Absolutely no indication we were pushing 70,000 psi…….

So had I not an Oehler M43 how would I know I was pushing pressures? The chronograph would tell me so. Looking at the max load in the #27 Data Manual we see the velocity for that charge is 2798 fps. Thus when I work up a load and get close to 2798 fps I can bet I am pushing pressures. It is a fool's errand to believe since the book says I can use more powder that I can do so safely with out excessive pressure.

It is with the advent of common chronographs that when velocities are reached below the charges listed in manuals that we get the myth of the "fast barrel". With velocity comes pressure.....no way around that.

Here’s a picture of the primers. Left to right are unfired WLRs then the cases in the order fired.

205663

My next post will give the details of the velocity/pressure workup using the H4350 data from the Speer #14 Reloading Manual with the Speer 180 SP.

[M-Tecs]

It is with the advent of common chronographs that when velocities are reached below the charges listed in manuals that we get the myth of the "fast barrel". With velocity comes pressure.....no way around that.


I generally agree with that statement. While less common today (due to higher BC bullets being allowed) Palma rifles tended to have undersize bores to increase pressure to gain velocity.

About 10 years ago I built 3 identical 6mm BR's on Tikka 595 actions. One for myself and one each for friends. I ordered three identical barrel blanks from Krieger. When they came in the bores and groove were within a .0001". Serial numbers were consecutive. No way to tell if they were from the same piece of bar stock. All chambered with the same carbide reamer and headspace were within .001". Basically as identical has possible yet one was consistently 150 per second slower.

Last year I chambered two NON Krieger barrels. Spec's. were a couple of tenths different but nothing I was concerned about. From the borescope I could not tell a surface finish difference. One had normal barrel break in copper fouling. The other has about 1,500 rounds through it. It never stopped heavily copper fouling and the maker basically said go fly a kit. Same owner not mine so I don't have any chrono data. The owner is having me replace the copper fouler this winter with a Krieger.

[44MAG#1]

Mr Gibson

Okay, with the chrono we know we can detect potentially high pressure. We all agree on that. I own a chrono.
Now what do you recommend for those that don't own a chrono?
For the interest of safety explain how these individuals should look for loads that are out of specs enough that they need to be toned down.
Plying us with pressure data is good but what about the individuals without chronos to at least measure velocity.
Are they out of luck? Do they at least need to spring for a chrono or fly by the seat of their pants and hope for the best or what?

[Larry Gibson]

Mr Gibson

Okay, with the chrono we know we can detect potentially high pressure. We all agree on that. I own a chrono.
Now what do you recommend for those that don't own a chrono?
For the interest of safety explain how these individuals should look for loads that are out of specs enough that they need to be toned down.
Plying us with pressure data is good but what about the individuals without chronos to at least measure velocity.
Are they out of luck? Do they at least need to spring for a chrono or fly by the seat of their pants and hope for the best or what?

They fly by the seat of their pants just like we all did prior to the advent of available chronographs.

Please don't get the wrong idea about this thread. I am not criticizing any loading manual. I am certainly not saying or insinuating that all data in loading manuals is suspect. This thread, i.e. the topic here, is simply that an error has been found with H4350 in the 30-06 with 178 - 180 gr bullets. All the pressure data I am posting is simply documenting that suspected error.

The manuals all say to work up loads. They also say if you change a component in a worked up load to re-work up the load. Yet both Hornady and Spear lump several of their similar weight bullets under the same load data. None of the manuals tell reloaders to track the lot numbers of the various components and to rework up the load if a different lot number is used. Mr. reloader most often doesn't. In loading for his '06 he buys a lb of the same powder without any idea of "lot to lot variation"), a box of the same primers (maybe, probably will just buy large rifle primers) and a box of the same 180 gr bullets (again maybe, many times he will just bask for a box of 180 gr bullets). Mr reloader goes on the assumption, as do almost all reloaders, that if he stayed with in the load manual data with his load it was safe. That assumption by most all reloaders is that a lb of H4350 is a lb of H4350 the same as any other lb of 4350. Mr reloader also believes 180 gr bullets are 180 gr bullets and large rifle primers are large rifle primers. A few of us may know better and even some manuals, buried deep in the fine print of their text, they also say there can be a difference. Well and fine but Mr reloader doesn't read the fine print of the text in the manuals, especially these days with load data taken from sites or forums. Odds are Mr reloader never read the fine print in his manual......he just went straight to the data pages and then most often to the maximum load. After all it's in the manual so it's safe, right? Most of the manuals say to watch for the "usual pressure signs" and to stop even if the load is under the maximum. That is good advise seldom followed by Mr reloader.

Point is Hodgdon, Hornady and Speer (the manuals used in this thread) know that. That is why their data is almost always safe to use as they stay with in SAAMI specifications now. However, just as I am not infallible, neither are they. Mistakes do occur no matter how careful they are/we are. I am, in this thread pointing out one mistake.

As I have mentioned before; reloaders who are not that experienced or who do not have a chronograph or access to one will do well to heed the advise of the manuals and stay within the manual data. Even with in that manual data loose primer pockets after 1 - 3 firings is a sure bet the pressure is excessive.

[Larry Gibson]

The Data in Speer’s Reloading Manual #14 for the 30-06 using H4350 with 180 gr bullets lists a starting charge of 54.0 gr and a maximum charge of 58.0 gr. Note the data is for use with five different Speer bullets of 180 gr weight. The velocity for the maximum charge is listed at 2756 fps. The test rifle was a M700 Remington with a 22” barrel. Also IMR4350 is also listed with a maximum load of 56 gr at 2639 fps and AA4350 is listed with a maximum charge of 57 gr at 2615 fps. Both of those loads are somewhat low in respect to past test of both powders with different 180 gr bullets. Given a 22” barrel 2700 fps can usually be expected w/o exceeding the SAAMI MAO of 60,000 psi. However my test rifle has a 24” barrel so a velocity of 2750 to 2780 fps should be just about at the SAMMI MAP with a powder of H4350’s burning rate.

Speer used Winchester cases trimmed to 2.484”, a maximum OAL of 3.340” and CCI 200 primers. The maximum load charges were also denoted as being compressed.

For my test I used the Speer 180 gr SP, Winchester cases trimmed to 2.484”, CCI 200 primers and an AOL of 3.330” (just of the lands of the test rifle). I was initially concerned about the use of the CCI 200 primer as it is about on the same brisance level as the Federal 210 which gave ignition and potential SEE problems in a previous test. The test rifle had a verification test of M72 Match reference ammunition fired prior to this test. The pressures and velocity of that test were within normal variance and were actually quite uniform.

As I was just about out of H4350 and could not find any locally I used my standard initial pressure work up test. This is loading three round of each charge from the start charge to the maximum charge in .5 gr increments. This gives us a velocity to pressure relationship that can quickly, with minimal expenditure of components, tell us what velocity (+/-) we can expect at a chosen maximum pressure level. Then with that narrowed down we can tweak the loads in a narrower range under the maximum pressure with ten shot groups for accuracy.

I started at Speer’s start load of 54.0 gr for the 1st test. It produced 2599 fps (all average velocities are corrected to the muzzle by the M43 Oehler) at 52,800 psi. The pressure traces are normal showing no sign of ignition problems.
205705

54.5 gr gave us 2636 fps at 54,000 psi. Again normal traces and all was looking good.

205706

55.0 gr gave us 2692 fps at 56,900 psi. Notice a little bit of a stutter beginning to appear at the start of the trace which is similar to the beginning of ignition problems I encountered using Federal 210 primers with this powder.

205707

55.5 gr gave us 2719 fps at 58,300 psi. This is the classic 30-06 level load with a 180 gr bullet; 2700 fps just under the SAAMI MAP. Problem though…..the small stutters at the beginning of the traces are becoming more pronounced. Notice the small spikes with a slight let off of pressure.

205708

56.0 gr gave us 2743 fps right at the SAAMI MAP of 60,000 psi. Here, with 2 gr less H4350, we are very close to the velocity listed for the maximum charge at 2756 fps. Were I developing a load with the use of a chronograph I would quit there and consider that a max load in my rifle. The small pressure spikes are still there.

205709

56.5 gr gave us 2761 fps at 61,000 psi. Above the SAAMI MAP but still useable in modern bolt actions were it not for the small pressure anomalies that are still there.

205710

57.0 gr gave us 2783 fps at 62,900 psi. The load is at 100% load density and we can plainly see the beginning of the bullet stopping momentarily and then moving again as evidenced in the trace of the 1st shot. It appears as the powder column in the case is compacted the soft brisance of the CCI 200 primer is not igniting the powders well.

205712

57.5 gr gave us 2803 fps at 64,100 psi. Note the pressure anomalies on the traces, especially the spike on the 2nd shot trace that’s where the bullet sticks in the bore just ahead of the leade. The pressure lets off as the bullet begins moving…….not good.

205711

58.0 gr, the maximum charge gave us 2823 fps at 65,300 psi. Definitely excessive pressure by some 5,300 psi over the SAAMI MAP. Also definite and pronounced ignition anomalies.

As with the data in Hodgdon’s Data Manual #27 the maximum charges of H4350 in the 30-06 used with one of the suggested bullets gives excessive pressure for the 30-06 cartridge. The maximum charge Hornady lists for use with 178 – 180 gr bullets is 55.3 gr. The tested charges very close to that of 55.0 – 55.5 g H4350 with the Sierra 180 gr SPBT and the Speer 180 SP have proven to be in line velocity and pressure wise with Hornady’s data.

Note; as previous testing has shown using a primer such as the Winchester WLR will raise the pressures 3 – 5,000 psi. Using a true magnum primer such as the Federal 215 will raise the pressure even more dramatically. The WLR and the magnum primers have sufficient brisance that ignition is not the problem it is with the Federal 210 and CCI 200 primers.

After 158 test rounds velocity and pressure tested with H4350 under 175 - 180 gr bullets in the 30-06 my suggestion is; if using H4350 in the 30-06 with 178 – 180 gr bullets use WLR primers, start at 53.5 gr and work up to 55.0 gr if wanting to keep the pressure at or below the SAAMI MAP for the 30-06. If, in a modern bolt action rifle, you want to venture into the MAP levels of the 22-250, 25-06, 270W, etc. then consider 55.3 gr as a maximum load, again using WLR primers.

[Larry Gibson]

..........About 10 years ago I built 3 identical 6mm BR's on Tikka 595 actions. One for myself and one each for friends. I ordered three identical barrel blanks from Krieger. When they came in the bores and groove were within a .0001". Serial numbers were consecutive. No way to tell if they were from the same piece of bar stock. All chambered with the same carbide reamer and headspace were within .001". Basically as identical has possible yet one was consistently 150 per second slower. .

Question; did you test them yourself consecutively with identically loaded cartridges?

[Grump]

Well, I'm feeling vindicated. Been sayin' for years that the only reliable "pressure sign" is the bullet. As in how fast it's going. If yur gittin' much more speed than the manuals or QuickLOAD say you should be getting with safe pressures, you ain't got no safe pressure. In the same barrel length!

I'm not the only one. At least one other posted a similar idea (though in a question as I recall) above.

"Oh goodie, MY gun gets more velocity than yours without any pressure signs!" is the mark of a person ignoring the most important pressure sign of them all.

As wisely noted above, those signs of brass failure all appear well outside of safe/spec pressures.

[M-Tecs]

Question; did you test them yourself consecutively with identically loaded cartridges?

Yes. Same loads same chrono.

[The Lord Flashheart]

New powder techonology does modify the adage of "Speed equals pressure" somewhat.

A topical example is why I have switched from H4350 to RL17 in the 3006.

The through-grain burn rate modifiers mean that whilst peak pressure may be the same as a equivalent load with H4350, the sustained pressure is greater and "push" on the bullet being proportional to the area under the pressure/time curve means greater velocity for no increase in pressue.

A friend had a few load professionaly pressure tested by ADI's lab in Australia and they bore these results out.

I believe the best indication of whether you are loading to excess pressure is the brass, if it doesn't last long reduce your load or buy lapua brass.

If you are still getting short case life with lapua brass then please don't shoot next to me! :D

[Larry Gibson]

Yes. Same loads same chrono.

"Basically as identical has possible yet one was consistently 150 per second slower."

Never said there weren't "slower" barrels........there are.

What I maintain, until someone shows me otherwise, is a "fast barrel". That means if your one barrel gave 150 fps faster velocities than is expected (by actual chronograph tests) out of a similar barrel (to spec) of the same length, chambered for the same cartridge and tested consecutively with the same ammunition.

[itsmer]

yep let me check first

[Larry Gibson]

New powder techonology does modify the adage of "Speed equals pressure" somewhat.

A topical example is why I have switched from H4350 to RL17 in the 3006.

The through-grain burn rate modifiers mean that whilst peak pressure may be the same as a equivalent load with H4350, the sustained pressure is greater and "push" on the bullet being proportional to the area under the pressure/time curve means greater velocity for no increase in pressue.

A friend had a few load professionaly pressure tested by ADI's lab in Australia and they bore these results out.

I believe the best indication of whether you are loading to excess pressure is the brass, if it doesn't last long reduce your load or buy lapua brass.

If you are still getting short case life with lapua brass then please don't shoot next to me! :D

Please.....let's not take what I said out of context. Your discussion, though quite correct in essence, constitutes a change of powder. My statements are relative only to the use of the same powder, same bullet, same case and same primer.

As an example; if the manual gives 2750 fps with a 22" barrel using the same combination with 57.5 gr H4350 powder and you reach 2750 fps with 55.5 gr of H4350 powder then you can pretty much be assured you are at a maximum pressure level. As the test results demonstrate increasing the velocity above that level increased pressures regardless of the primers or make of bullets used.

"Increased velocity above published, documented results equals increased pressure" applies only to a given powder with a given weight of bullet in a given cartridge.

[The Lord Flashheart]

Why yes and this why CIP specifies muzzle energy for cartridges which is a better and more scientific way of setting limits on a cartridge's capabilities than purely muzzle velocity. :)

What do you think of the idea of brass life setting the practical limit for loading, out of interest?

[Digital Dan]

My opinion only...........

205786

[Larry Gibson]

.....What do you think of the idea of brass life setting the practical limit for loading, out of interest?

Guess what you mean by "brass life" is the determining factor.

For some years my standard elk hunting in the 30-06 was the Hornady 190 SPBT over a lot of H4831SC at 2733 fps. I developed the load working up to it and never had any indication of pressure until the 5 - 6 loading of the cases. Then I had loose primer pockets. That load had accounted for several elk out of 2 different rifles and I was satisfied with it except for what I considered too short of case life. To me with a high intensity load the cases should last for 20+ firings.

Back in '08 when I got the M43 Oehler I pressure tested that load in my current '06 hunting rifle, a Winchester M70 (U.S. Repeating Arms). I found the pressure to be 64,700 psi. Since then I backed the load off to 2648 fps (doubt any elk will know the difference) at 61,300 psi. I sat down at the shooting bench with 5 new Winchester cases, a box of 190 SPBTs, primers and a pound of H4831SC. Using a Lee Target loader I loaded the cases 20 times each with that load. The primer pockets are still good to go after 20 firings per case. That lower reduced load is my hunting load now.

Yes, you can push the envelope and get away with it for a while depending on what you're willing to call "case life". I used to do that. I don't any more because maybe I'm getting old and have learned if I want magnum level performance instead of pushing pressures in standard cartridges I should get the magnum.

[The Lord Flashheart]

Case life is exactly that, how long the cases last before they are unsafe to use by dint of loose primer pockets or excessive stretching at the web.

I ask as reading your posts on this very informative thread it seems that loose primer pockets correlate very strongly with excessive pressure from your data as well as mine.

This then raises the question of whether absolute chamber pressure is in fact a measurement we are interested in, in and of itself, or whether we are interested in the effect that pressure has on the brass?

After all, the brass will let go well before the steel does.

[44MAG#1]

Mr Gibson

Let throw another what if in the equation.
Do we know if Speer or Hornady uses multiple factory rifles to test velocity in?
If they grab one out of the rack to use to list velocity from how do we know that it isn't a "slow" barrel as you said we know there is slow ones?
How do we know that the rifle they use hasn't been shot so many times that the throat hasn't advance in it?
Do we just assume that the rifle they use is typical in delivered velocity and not abnormal?
What about Handguns?
If a lab post velocities from a pressure barrel how do us neophytes deduce the velocity to a factory rifle with maybe the same length or even shorter barrel?
What about Handguns? Lyman post velocities for the 44 mag from a 4 inch pressure barrel. What about a 7.5 inch revolver? How do we conjure up the velocity we should be getting in a 7.5 inch to deduce we are over pressure in our handgun?
Remember if pressure data in rifles can be wrong it can be wrong in handgun data.
I'll turn it over to you on this.

[Larry Gibson]

44MAG#1

To answer your questions;

Do we know if Speer or Hornady uses multiple factory rifles to test velocity in? If they grab one out of the rack to use to list velocity from how do we know that it isn't a "slow" barrel as you said we know there is slow ones?

They both list the use of factory rifles to obtain the velocities. Both supposedly adhere to SAAMI guidelines. The maximum velocities each list are commensurate with velocities published by other competent sources. We all take some things for granted; how do we know our chronograph is correct? How do we know our micrometer or caliper is correct. There are ways to compare them with a known standard. I'm sure if either Speer or Hornady had a "slow rifle barrel" that did not give the velocity expected with reference or a known reload they would not use that rifle. Slow rifles as such are relatively rare.

How do we know that the rifle they use hasn't been shot so many times that the throat hasn't advance in it?

I would suspect the technicians at Speer and Hornady to be aware of that potential. As they should be keeping a round count in their pressure test barrels I would suspect they also keep a round count for their rifles. Wouldn't surprise me if measuring throat erosion is done also. My pressure test barrel used in this thread now has 1102 rounds through it. I check throat erosion every 200 rounds.

As noted in this thread at the beginning of such tests a test string of reference ammunition is shot to verify the system and check that measured velocities and pressures were with in a normal +/- variation. Any serious reloader even using a chronograph can and do the same to validate the velocities measured on the chronograph are consistent with past readings. The start screen should be placed the same distance from the bench or muzzle at each set up. A .22LR and a brick of quality 22LR ammo can be used as "reference ammunition". Shoot five 10 shot strings as a base. Then each time you set up the chronograph shoot a ten shot test string. The aver velocity, SD and ES should fall with in or be close to the average of the first series of baseline tests. If you do that you will know all is correct with your other tests.

Do we just assume that the rifle they use is typical in delivered velocity and not abnormal?

Most everyone makes that assumption, especially new or occasional reloaders with only one reloading manual. I got my 1st chronograph in '74. It immediately opened my eyes to the inconsistent velocities published back then. Most factory velocities were from 26" test barrels. The more I chronographed the more reliable I found published velocities recorded in actual factory rifles in manuals such as Speer's and Hornady's to be.

If a lab post velocities from a pressure barrel how do us neophytes deduce the velocity to a factory rifle with maybe the same length or even shorter barrel?

With luck, that's about all to say about such deductions. The cost of a chronograph is small compared to the actual cost of components used up trying to "deduce" such not to mention the cost of a firearm or medical bills if your "deducing" isn't right. Chrony's are not expensive and they are accurate enough. I learned a long time ago that if I had to resort to guessing such then I probably wasn't going to be right. Yes back in the day we all had to guess and cogitate. We no longer have to. Over the years I have chronographed hundreds of loads for other shooters who simply asked. My only requirement was full load data and at least 5 rounds.

What at about Handguns? Lyman post velocities for the 44 mag from a 4 inch pressure barrel. What about a 7.5 inch revolver? How do we conjure up the velocity we should be getting in a 7.5 inch to deduce we are over pressure in our handgun?

Again....with luck. There are numerous scales of "fps gain/loss" to be used. Most of them are actually quite close. There also is QL. Then there is also this forum.

Remember if pressure data in rifles can be wrong it can be wrong in handgun data.

Of course they could be. However, please don't feel this thread is about condemning Hodgdon's, Hornady's or Speer's manuals. I am not. I am only pointing out one error that I've found and I've not yet found any handgun data that is in error. I use those three manuals plus others that have been published in the recent past. Even then I understand that much of the data is simply republished and not retested as there've been no reported errors. Thus I cross reference.

[44MAG#1]

Since no one has brought up handgun data let me be the the goofy one. We will take Speer data and Lyman data. In 44 Magnum data Speer they list 9 to 11 gr Unique with Speer cases, CCI 300 primers and the RCBS 250 Keith at a 1029 to 1211 in a Ruger Redhawk 7.5 inch
Lyman 44 Magnum data list in their 49th Edition 9.8 Unique to 13.0 gr Unique and the Lyman 429421 from 912fps to 1147fps in a 4 inch pressure barrel using Remington cases CCI 300 primers.
Now 2 grains are a big spread considering the charge weight. I know the cases are different and the bullets are slightly different but a 2 grain spread??
How would you determine the safe charge weight in these two examples? One chronoed from a 7.5 inch revolver and one from a 4 inch pressure barrel.
While the original post was about rifle data let's consider data data and expound on handgun data too just to cover all the bases since bolt rifles have a better safety margin than most revolvers on the average.

[Larry Gibson]

44MAG#1

Since no one has brought up handgun data let me be the goofy one. We will take Speer data and Lyman data.

In 44 Magnum data Speer they list 9 to 11 gr Unique with Speer cases, CCI 300 primers and the RCBS 250 Keith at a 1029 to 1211 in a Ruger Redhawk 7.5 inch.

Lyman 44 Magnum data list in their 49th Edition 9.8 Unique to 13.0 gr Unique and the Lyman 429421 from 912fps to 1147fps in a 4 inch pressure barrel using Remington cases CCI 300 primers.

Now 2 grains are a big spread considering the charge weight. I know the cases are different and the bullets are slightly different but a 2 grain spread??

Two grains is not really a "large spread" considering the two different bullets used. Look again at the Lyman #4 Manual. Bullets 429421 at 245 gr, 429640 at 250 gr and 429244 at 255 gr have max loads of Unique of 13, 10.5 and 12.1 gr.......a 2.5 gr spread. Thus I don't see any problem with the Speer max Unique load of 11 gr with the 250 gr RCBS bullet. All four are different bullets. Using different bullets does make a difference.

How would you determine the safe charge weight in these two examples? One chronoed from a 7.5 inch revolver and one from a 4 inch pressure barrel.

I would consider the data for each one of them as correct and "safe" for the particular bullet they used. From the differences in max loads between the various weights I do not advise using data for another bullet and just going to the max load. With most cast bullet rifle loads we can substitute other "similar" cast bullets because the pressures generated by cast bullet loads are well below the maximum pressures for most rifle cartridges. It is different with handgun cartridges, especially the magnum cartridges, because they are most often loaded to their specified maximum pressures with most cast and jacketed bullets.

While the original post was about rifle data let's consider data and expound on handgun data too just to cover all the bases since bolt rifles have a better safety margin than most revolvers on the average.

This thread was not about rifle data in reloading manuals in general, it was/is about two specific data entries in the Hodgdon #27 and Speer's #14 reloading manuals of an obvious error in listed data with one powder (H4350) using 175 - 180 gr jacketed bullets in the 30-06 cartridge. This thread is not questioning any other data in those manuals.

To expound I would refer you to your Speer #14 manual. Read Chapter 5, Velocity, Energy and Pressure, for what I consider one of the best discussions regarding all three.

[Larry Gibson]

44Mag#1

Sorry had to close that last post out before I was finished.

Back to your question; assuming you have a Ruger 44 Mag with 7 1/2" barrel and a custom mould that casts a 250 gr SWC. That specific mould is not listed in any of the manuals and doesn't have specific data for it. What to do for a load with Unique?

I would look at the Speer manual because it has loads for a 250 gr cast bullet out of a Ruger with a 7 1/2" barrel. I would use a standard primer such as the CCI 300 (what Speer used) in one lot of 44 magnum cases. I would start with Speer's start load of 9 gr Unique and chronograph 10 - 12 rounds. If the average velocity (testing in 65 - 75 degrees) was within +/- 20 fps I would feel comfortable that the load was in the same pressure range as Speer's test.

[note; that exact load using the RCBS 44-250-KT in Winchester cases out of my 6 1/2" Ruger runs just under the Speer 1056 fps. It pressure tests in my Contender test barrel at 21,100 psi].

With the 7 1/2" barreled Ruger I would then work up in .3 gr increments not to exceed Lyman's 13 gr max charge until 1259 +/- 10 fps was reached unless hard ejection became a problem. Given a 9 gr start load that gives 1056 +/- fps I suspect 1259 fps will be reached well before 13 gr is reached.

If you don't have a chronograph then I will refer you back to Digital Dan's only opinion in post #108.

[44MAG#1]

Thanks Mr. Gibson.
As I have been a user of slower powders in the 44 Mag and most of the magnum revolvers and have been reloading for 47 years I can always learn something.
I have read the chapter 5 in the Speer manual #14 just after I got it when they first came out. Nothing new in it.

[Larry Gibson]

Nope, nothing new......just a lot that most reloaders don't know, especially those who just get load data off the internet........

[Digital Dan]

Larry, you have probably experienced more epiphanies in the world of reloading that most of us wankers have collectively and I do appreciate your sharing the experience and knowledge. I ventured off the beaten path a couple years back with the creation of a wildcat not unlike the .30 Badger or .30 Reece, only difference being intended use and objectives.

I used a .357 case with a neck just a hair shy of .5" in length, the bullet is cast and presents as a bore rider of ~185 grains weight. My intention was strictly for use with a suppressor with velocity restricted to subsonic. Fella wants a cold splash of reality in this world he needs to start out with something like this without any referenced starting point. To put it politely, it is a learning experience. The objectives were mine alone, the use is task specific and while I've no doubt it will stretch much further in the performance envelope, the operating parameters serve a purpose and I have had the discipline to remain within those guardrails. I work on behalf of a state agency in a program for eradication/control of feral swine on state lands that have residential properties on two sides and industrial activity on a third. About 1,200 acres all told. Their constraints are many, but quiet is one of their mantras. I did this for several years using CB short and they work well enough, but admit I did have to shoot one cranky old boar twice out of 80+ pigs.

Not to belabor the rationale, the thing I've encountered with my cartridge in testing loads with many powders/primers/bullet alloys/C.O.A.L. is pretty much the the realization of just how sensitive the little beast is to very minor changes. It gives rise to the thought that likely most cartridges are equally sensitive, it is just that lacking close attention and some equipment for evaluation such as a chronograph, the average Joe is groping in the dark. His only realistic path is to rely on published data and be diligent in the pursuit.

Things that have surprised me with this affair?

-Same load specs, change in BHN of two whole digits can change velocity 50 fps or slightly more.
-Same specs, clean case versus dirty case? 50 fps average velocity change...
-Same components, 6% reduction of charge weight with powder X in a clean case and +2 on BHN on the bullet = velocity with previous comparable alternatives.
-.001" difference in bullet diameter size? 150% difference in group size at 50 yards.
-2 BHN numbers? 1"+ groups versus .25" groups for 5 shots @ 50 and this is repeatable.

There is more, but I think it illustrates the subtle influences at play and how marked the results can be. As I said early, very educational. It gives pause to the thought of attempting to achieve mag velocities with a smaller standard case.

Dan

[B R Shooter]

Don't go talking about a wildcat, there is no data for it to tell you how to load it.

[Digital Dan]

Wasn't making a point about 'cats, just the influences of very minor (?) alteration of the load/s. Cartridge style is largely irrelevant I think, and that means work-a-day cases like the .30-06 likely exhibit the same characteristics.

[buckshotshoey]

Wasn't making a point about 'cats, just the influences of very minor (?) alteration of the load/s. Cartridge style is largely irrelevant I think, and that means work-a-day cases like the .30-06 likely exhibit the same characteristics.

I think he was trying to be a smart A.

[Larry Gibson]

He certainly is correct about minor alterations of the load having influences on the load. His example especially with the small capacity case of his 'cat. I found that out a long time ago in '74 when I got my 1st Oehler chronograph with the 22 Hornet, 221 Rem and the 30 Carbine. With such small capacity cases, even in the 223 Rem, it is best to work powder charges up in .2 - .3 gr increments. The same in cartridges up through 30-30 capacity. In .308W or larger up through the "short" magnums .5 gr is a safe increment. Also changing bullets or primers can cause a major change as we have demonstrated with the tests in this thread.

New reloaders and those without chronographs are well suited to stay within published data from major manuals who actually test their data. Yes, I have pointed out one anomaly here in this thread but that's the only one I've found so far in the last 9 years since I began pressure testing. The data in the Hodgdon, Hornady, Speer, Lyman and Sierra manuals is pretty reliable.

[nagantguy]

Mr. Gibson thanks again for this post from your actual field research with the equipment most of us don't have ; as per out PMs I have backed off my loading of H4350 down to our agreed upon safe window ; the primer pockets on the brass and every aspect of the brass itself that has had 2 firings at what you determined to be potentially an over pressure charge is fine,but these were new cases. Funny thing in the new loading window I found two sweet loads that were not sweet loads during initial testing. The other thing I noted my chronographed velocity at the old near max charge weight was right on the heels of listed max, the new "max" as we discussed in PMs is a full 1.2 grains less and velocity is only slightly lower;70 -72 fps slower... now this is only with chronograph data on 10 of the old near max loads and 5 of the new near max with new Remington and Winchester cases H4350 powder Hornady 178-EDL-x in a ruger Mark 2 in 30-06 with cci benchrest 2 primers.
The new sweet spot that was not sweet the first time through produced a sub one inch 5 shot group exactly 2.8 inches high of poa at a known 102 yards.

[greenjoytj]

I find that AMAZINGLY interesting. My mentors have always told me than none of the traditional pressure signs could be relied on to keep me safe. The reason is that by the time they appear it is already way too hot. They taught me that these signs appear at about - - - - > 70,000 psi.

The most accurate statement of pressure sign reading for any home reloader.
Reading primers for pressure is as accurate as reading tea leaves. By the time the physical pressure signs appear your already way over the SAAMI limit.
This reminds me of the story I read long ago in a gun magazine about the development of the wildcat 7mm STW. Handloads looks ok, but when lab pressure tested they were found to be to hot. And this was from an experienced handloader.

I read the the labs the collect data for loading manuals use the minimum spec pressure guns to get the pressure numbers, but the published velocity data is collected from real world off the shelf firearms.
So the MV would be more in line with what the home reloader would see.

[44MAG#1]

Not all velocity data is collected from production guns. If one looks at several reloading data book one will see that.

[Ford SD]

3 Days ago Finally got around to loading Gordons Reloading Tool on my computer ...... think free Quick load software

Gordons Reloading Tool "GRT" is a software for handloaders and ammunition designers. It simulates combustion characteristics, pressures and bullet speeds through ballistic parameters and formulas.

when I started loading 300 aac Blackout One of my First outings , maybe the 2nd, I experienced expanded primer pockets,
Primers were on the flat side, but not to the extreme. just where you could push new primers in app 80% of the way in with your thumb. Not good

So I then, searched harder for data and did not use any data that was at the high end.
tried to use the lowest start published date as my starting loading charge
or used start data -5% as my start

I am sorry to say the maker of GTR has died so if you want/ need the software download it now ( you can make donations to keep GRT up on the www
Not sure if the other people working with GRT will/ do any updates in the future

I have spent the last 3 days entering loads that have worked and have not worked for me in the past ..... Like the above 300 BO load that had enlarged primer pockets

Some things I have found, you can save your work under different file names / folders ets

Comparing my Velocity data to GTR has been very close some times as close as 25-50fps
and in some instance finding out why i had the results I did have.
Like bad case sealing and dirty cases on start loads

to print them you have to do a Screen shot (control+Print screen)/ open and paste in a paint program and then you can print it
if anyone has a way to print from GRT let me know

What I have been doing is printing my data sheets on one side of the paper and data entered from GRT on the other side

No data for red dot or sr4759 and others

If you know how to add powders in to GRT, I would like to know

you can add your own Cast bullets .... added some NOE bullets to the my user database
you can change case volume H2O for example
you can change barrel length / weight etc

you need to change cast bullet data ie .311 Dia to .308 or you get a warning .... easy fix

[Ford SD]

GRT
has cast bullets under Lyman, lee so look around under different names ...... and find what you are looking for
using expert mode BTY

[olafhardt]

I spent a significant amount of time doing instrument caliibration and designing measurement systems. When I got into reloading, I was somewhat aghast at chamber pressure measurement techniques. I think the best you get is a halfway guess. It is my opinion that pressure measuring in shooting .