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

[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!

[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!

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...........

[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.