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Old October 4, 2012, 05:41 PM   #1
hardworker
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Reloading Manuals not consistent?

I'm trying to work up a load for 357 using a 158gr speer jacketed hollowpoint. I'm using Alliant 2400. The problem I'm having is the reloading manuals I've read aren't consistent.

I've got a MidwayUSA Load Map for 357 and it states the starting load at 9.7gr and 11.5gr.

A Speer reloading manual gives a starting load of 11.2gr and a max of 12.5gr.

OAL for both of these manuals is 1.570 give or take a hundredth.

But the real inconsistency comes from the Alliant website, the closest load data for my bullet is the Speer GDJHP, which is almost identical everywhere else. This website gives a charge of 14.5 grains.

The 14.5gr concerns me for obvious reasons, being such a higher amount than anything else I've read.

From what I've read on the internet, 2400 doesn't like light loads, so that's where the 9.7 concerns me if the 14.5 gr from the Alliant website is correct. I've read on the internet that 14gr is a standard load for this configuration.

So I guess what I'm asking is which of these sets of numbers does everyone else use?
Is it normal for there to be this much inconsistency between load sources? I'd hate to blow up my Model 19.
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Old October 4, 2012, 05:45 PM   #2
fishbones182
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9.7 is a fine starting point. Load a few in say .3 or .4 grain adjustments watch for accuracy and pressure signs. Once you find a round that is shooting good with no pressure signs then work the load up and and down by a tenth of a grain at a time for the best load for your gun. None of the manuals are spot on thats why its best to have several and reference all of them. Then find a spot your comfortable starting at and have at.
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Old October 4, 2012, 07:59 PM   #3
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Any manual is what that company used on a particular day, in a particular gun (or universal receiver), with a given barrel length, at a given temperature, at a given elevation, with a given phase of the moon, etc......you get the picture. There are a LOT of variables that go into writing a loading table. It's a wonder there aren't MORE variations.

This is a good reason to buy SEVERAL manuals and compare them, and then decide what will work best for you.
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Old October 4, 2012, 08:17 PM   #4
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I was advised to use just one manual until I had enough experience to deal with variables. For the first five years I used just that one, a Lyman #43, and never felt I needed anything else until several new cartridges and new powders came on the market. By that time the differences between manuals was no big issue to me. Today I have over two dozen, bought at an average rate of one every two years, but I still use that old Lyman more often than not.

As you may expect, I also suggest new guys stick to one manual until you get well grounded, otherwise you'll often be confused for no good reason.

Book OAL is what the book makers used to develop the listed data, it's no more a law for the rest of us to follow than their powder charges are.
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Old October 4, 2012, 09:46 PM   #5
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Unless you are very familiar with the cartridge and powder that you are using it is best to start with the starting loads. The load books are not a recipe book, but rather a guide. If you do use multiple manuals and have conflicting data either start with the lowest starting loads, or (and you should do this anyway) look at the details of their data. The bullet diameters, barrel lengths, primers used and so forth. Many times it will become clear in the details of the whats and whys. Then you can extrapolate your start charge.
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Old October 4, 2012, 10:45 PM   #6
testuser
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Yeah, this drove me nuts at first, too.

I agree with everyone, I always use the most conservative data starting out.

Load data changes often, so check the website of the powder makers regularly!

The powder and bullet companies update their data every so often for a very good reason. Power composition has been changed over time, more sensitive pressure testing is available, misprints happen, etc.

Alliant owns Speer, so an up-to-date Speer manual and Alliant data should agree! Speer 13 shows a MAX charge of 14.8 grains for a 158 grain Gold Dot Hollowpoint in .357 magnum, the website shows an identical max charge of 14.8 grains of 2400 for the same bullet.

I don't want to sound harsh, but your manual sounds like it's out-of-date.

Heck, even my book is out of date (Speer 14 is out, I checked, all of my loads stayed the same), but I'm only using Alliant powders and always comapre Alliants current data on their webpage to Speer 13. If they disagree, then I'm using the more recent data. I also have an up-to-date Hornady manual as well, just to sanity check Alliant's data.

Be sure to use the most current data available from reputable powder companies or bullet manufacturers only. Midway USA is a great company for merchandise, but I wouldn't trust them to stay current on load data. Is there a date on the book you received from Midway?

Old reloading manuals are great to learn the process, but generally a poor source of data. Use them as reference material for the PROCESS only.

Also, charge weight will differ by bullet profile. Make sure you're not comparing a jacketed HP to some other style of bullet.

Getting a chronograph is a good idea, too. With a slow burning powder like 2400 you'll note erratic velocity and probably poor accuracy when loading too light. (You might even seen soot around the case mouh from a poor gas seal if pressure is too low.) I don't lean too heavily on a chronograph, but, to me, it's an important tool.

Last edited by testuser; October 4, 2012 at 10:55 PM.
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Old October 4, 2012, 11:38 PM   #7
Clark
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357 mag max has gone below 38 Special:
"Speer 6" 1964 38 s&w special 160 gr. soft point 11 gr. 2400
"Speer 6" 1964 357 mag 160 gr. soft point 15 gr. 2400
Midway "Load map" 1999 357 mag Speer 160 gr. soft point 10.9 gr. 2400


What went wrong that Midway could get the max loads so far off and make
a useless load book?
They used an "Oehler System 83 and piezoelectric transducers, the latest
in industry standard equipment".

The way I understand this is from John Bercovitz's 1993 post when he was still at JPL:

A friend asked why steel cases aren't more common since they would
allow higher chamber pressures. I thought that as long as I had
written something up for him, I might as well post it here:

Material Properties
CDA 260 cartridge brass: barrel steels:
Young's modulus = 16*10^6 psi Young's modulus = 29*10^6 psi
Yield stress = 63,000 psi min. Yield stress: usually > 100,000 psi

I was going to get back to you and explain further why brass is a better
cartridge case material than steel or aluminum. Sorry I took so long. I
left you with the nebulous comment that brass was "stretchier" and would
spring back more so it was easier to extract from the chamber after firing.
Now I'll attempt to show why this is true given the basic material properties
listed above.

A synopsis would be that the propellant pressure expands the diameter of
the thin wall of the cartridge case until it contacts the interior wall
of the chamber and thereafter it expands the case and the chamber
together. The expansion of the cartridge case, however, is not elastic.
The case is enough smaller in diameter than the chamber that it has to
_yield_ to expand to chamber diameter. After the pressure is relieved by
the departure of the bullet, both the chamber and the cartridge case
contract elastically. It is highly desirable that the cartridge case
contract more than the chamber so that the case may be extracted with a
minimum of effort.

A quick review of the Young's modulus: this is sort of the "spring
constant" of a material; it is the inverse of how much a unit chunk of
material stretches under a unit load. Its units are stress / strain =
psi/(inch/inch). Here's a basic example of its use: If you have a 2
inch by 2 inch square bar of steel which is 10 inches long and you put a
10,000 pound load on it, how much does it stretch? First of all, the
stress on the steel is 10,000/(2*2) = 2500 psi. The strain per inch will
be 2500 psi/29*10^6 = 0.000086 inches/inch. So the stretch of a 10 inch
long bar under this load will be 10 * 0.000086 = 0.00086 inches or a
little less than 1/1000 inch.

Yield stress (aka yield strength) is the load per unit area at which a
material starts to yield or take a permanent set (git bint). It's not
an exact number because materials often start to yield slightly and then
go gradually into full-scale yield. But the transition is fast enough
to give us a useful number.

So how far can you stretch CDA 260 cartridge brass before it takes a
permanent set? That would be yield stress divided by Young's modulus:
63,000 psi/16*10^6 psi/(inch/inch) = .004 inches/inch.

How far can you stretch cheap steel? Try A36 structural steel:
36,000 psi/29*10^6 psi/(inch/inch) = .001 inches/inch.
How about good steel of modest cost such as C1118?
77,000 psi/29*10^6 psi/(inch/inch) = .003 inches/inch.
(Note that C1118 doesn't have anywhere near the formability of CDA 260.
Brass cases are made by the cheap forming process called "drawing"
while C1118 is a machinable steel, suitable for the more expensive machining
processes such as turning and milling.)

What about something that's expensive such as CDA 172 beryllium copper?
175,000 psi/19*10^6 psi/(inch/inch) = .009 inches/inch.
(This isn't serious because CDA 172 is pretty brittle when it's _this_
hard.)

Titanium Ti-6AL-4V
150,000 psi/16.5*10^6 psi/(inch/inch) = .009 inches/inch
(This is an excellent material though expensive and hard to work with.)

Really expensive aluminum, 7075-T6
73,000 psi/10.4*10^6 psi/(inch/inch) = .007 inches/inch
Cheap aluminum, 3003 H18
29,000 psi/10*10^6 psi/(inch/inch) = .003 inches/inch
(Aluminum isn't a really good material because it isn't strong and cheap
at the same time, it hasn't much fatigue strength, and it won't go over
its yield stress very often without breaking. So you can't reload it.
It makes a "one-shot" case at best. Also, 7075 is a machinable rather
than a formable aluminum, primarily.)

Magnesium, AZ80A-T5
50,000/6.5*10^6 = .0077
(Impact strength and ductility are low. Corrodes easily.)

+Here's the important part: Even if you stretch something until it
+yields, it still springs back some distance. In fact, the springback
+amount is the same as if you had just barely taken the thing up to its
+yield stress. This is because when you stretch it, you establish a new
length for it, and since you are holding it at the yield stress (at
least until you release the load) it will spring back the distance
associated with that yield stress. So the figures given above such as
.004 inches/inch are the figures that tell us how much a case springs
back after firing.

Changing subjects for a moment: How much does the steel chamber expand
and contract during a firing? Naturally this amount is partially
determined by the chamber wall's thickness. The outside diameter of a
rifle chamber is about 2 1/2 times the maximum inside diameter,
typically. The inside diameter is around .48 inches at its largest.
Actual chamber pressures of high pressure rounds will run 60,000 psi or
even 70,000 psi range if you're not careful.

One of the best reference books on the subject is "Formulas for Stress
and Strain" by Roark and Young, published by MacGraw-Hill. Everyone
just calls it "Roark's". In the 5th edition, example numbers 1a & 1b,
page 504, I find the following:

For an uncapped vessel:
Delta b = (q*b/E)*{[(a^2+b^2)/(a^2-b^2)] + Nu}

For a capped vessel:
Delta b = (q*b/E)*{[a^2(1+Nu)+b^2(1-2Nu)]/(a^2-b^2)}

Where:
a = the external radius of the vessel = 0.6 inch
b = the internal radius of the vessel = .24 inch
q = internal pressure of fluid in vessel = 70,000 psi
E = Young's modulus = 29 * 10^6 psi for barrel steel
Nu = Poisson's ratio = 0.3 for steel (and most other materials)

A rifle's chamber is capped at one end and open at the other but really
it's not too open at the other end because the case is usually bottle-
necked. You'd have to go back to basics instead of using cookbook
formulae if you wanted the exact picture, but if we compute the results
of both formulas, the truth must lie between them but closer to the
capped vessel.

For an uncapped vessel:
D b = (70000*.24/29*10^6)*{[(.6^2+.24^2)/(.6^2-.24^2)] + .3} = .00097

For a capped vessel:
D b = (70000*.24/29*10^6)*{[.6^2(1.3)+.24^2(.4)]/(.6^2-.24^2)} = .00094

There's not a whole heck of a lot of difference between the two results
so let's just say that the chamber's expansion is .001 inch radial or
.002 inch diametral.

The cartridge case's outside diameter is equal to about .48 inch after
the cartridge has been fired. So its springback, if made from CDA 260,
is .004 inches/inch (from above) * .48 inch = .002 inches diametral
which of course is just the amount the chamber contracted so we've just
barely got an extractable case when chamber pressures hit 70,000 psi in
this barrel. This is why the ease with which a case can be extracted
from a chamber is such a good clue as to when you are reaching maximum
allowable pressures. By the same token, you can see that if a chamber's
walls are particularly thin, it will be hard to extract cases (regardless
of whether or not these thin chamber walls are within their stress limits).
A really good illustration of this can be found when comparing the S&W
model 19 to the S&W model 27. Both guns are 357 magnum caliber and both
can take full-pressure loads without bursting. The model 27 has thick
chamber walls and the model 19 has thin chamber walls. Cartridge cases
which contained full-pressure loads are easily extracted from a model 27
but they have to be pounded out of a model 19. So manufacturers don't
manufacture full-pressure loads for the 357 magnums anymore. 8-(

We can see from the above calculations that a steel case wouldn't be a
good idea for a gun operating at 70,000 psi with the given 2.5:1 OD/ID
chamber wall ratio if reasonable extraction force is a criterion. Lower
pressures and/or thicker chamber walls could allow the use of steel cases.
jb


What does it all mean?
1) The 357 mag max load started out at the threshold of sticky cases, and then backed off a safety margin of powder charge to avoid sickly loads.

2) Then they measured the pressure and registered that.

3) Then they made thin wall 357 mags that got sticky cases with less pressure. So they changed the pressure registration. Loads were reduced.

4) Then they came up with a new way of measuring pressure, and that inspired them to make loads reduced even further.
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Old October 5, 2012, 05:34 AM   #8
hardworker
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The book is the first volume copyrighted in 1999, so it is definitely not new. I did not know that Alliant owned Speer, so that makes me feel better about the data on Alliant's website for these bullets. I plan on making some this weekend. Seems like the consensus here is to start at 9.7 and work up a few tenths at a time.
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Old October 5, 2012, 06:17 AM   #9
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Actually Alliant doesn't own Speer,ATK owns both including several more sporting goods companies. Reloading manuals data is based on components used as well as testing methods at the time the data was created so there is going to be variations between manuals.


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Old October 5, 2012, 10:51 AM   #10
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I call the powder mfg for their load recommendations EVERY time I buy powder...and cross check it with different manuals. Powder mfgs DO change formulations and loading valuies so using a 1999 manual could lead you to dangerous results. Consider data from 1999 as obsolete and a potential safety hazard.

bc
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Old October 5, 2012, 01:29 PM   #11
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I always use the bullet manufactures data, unless there is none.

Alliant is the one exception…

They list Speer bullets so I will use their data, for Speer bullets.

If it does not agree with the bullet manufacture’s data I use the lower number or call.

Really like calling cause they are both good groups and always answer my questions.
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Old October 5, 2012, 02:05 PM   #12
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I own loading manuals going back 15 years from numerous manufacturers, there are many differences just like you describe.

I have thoroughly tested, good safe recipes that are well above the stated max in other manuals, the biggest differences are cartridge case, primer, barrel length, and firearm used.

I would NOT put these in just any rifle and shoot them, some of these loads are for MY rifle alone.
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Old October 5, 2012, 02:41 PM   #13
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Reloading Manual Consistentcy

one problem i have with the constant change of data due to 'modifications to powders' is that i still have old powder. nowhere i have been able to find do the powder manufacturers state that these changes are applicable to lot number such and such and higher. my powder is still what the old manual said it was, and it shoots safely and reliably.
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Old October 5, 2012, 02:46 PM   #14
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After all my load developement and testing rifles that shoot my loads I've come to the conclusion that manuals are merely a guideline that has been tested proffessionally. Having said that none of my loads actually emulate any I've found in manuals. They are close, but there are difference that I accumulated on my own like powder weights, different primer, different cases, etc.

That's what all the damn fun is about!!
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Old October 5, 2012, 03:14 PM   #15
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Clark,
That was the most interesting post I've read in a while.
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Old October 5, 2012, 06:20 PM   #16
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Great point about them being a guideline, I'll make sure to remember that as well. My Lyman #49 came in the mail today and it's different than my Lee manual. Like many have stated I'll start low and work my way up slowly.
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Old October 5, 2012, 10:27 PM   #17
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I agree that manuals are guidelines, with one exception: if you exceed maximum published loads, avoid my range, please.
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Old October 13, 2012, 01:22 PM   #18
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Am I Safe?

I am trying to get back into reloading after a lengthly period of inactivity (15 or so years). I have a Speer #10 and #14 manual and a Sierra 3rd Edition and 5th Edition. I was getting ready to load a bunch of 158 gr. JHP .357 and 240 gr JHP .44 mag rounds when I realized that my old pet load data was off the scale for the new manuals. My old .357 load was 15.5 grains of 2400 and a CCI 550 primer. Now the new Sierra manual says no magnum primer and 15 gr. max and the Speer manual says 14.8 gr. max and no magnum primers. I am getting similar info for the .44 mag loads. Is it safe to use mag primers or my old pet loads? I have 600 rounds of primers for the .44 that will be pretty much useless with this new load data and I have already primed 200 rounds of .357 with mag primers and have another 300 primers I just bought. Now what? Is it safe to load my old pet loads or should I scrap it all and start over from scratch?
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Old October 13, 2012, 06:57 PM   #19
wncchester
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"... your manual sounds like it's out-of-date. "

No manual is 'in-date' for any rifle except the one used to develop the listed data. That's why it's important for us to follow the one instruction that actually matters, "Start low and work up ....." etc.
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Old October 14, 2012, 10:00 AM   #20
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book learnin'

I use my (unbelievably extensive) collected data as a guide only, mostly looking for a place to start.

Then I work UP....
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Old October 14, 2012, 01:15 PM   #21
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Quote:
"... your manual sounds like it's out-of-date. "

No manual is 'in-date' for any rifle except the one used to develop the listed data. That's why it's important for us to follow the one instruction that actually matters, "Start low and work up ....." etc.
It's possible. For example, Alliant now says NOT to use Blue Dot for .41 Magnum and certain loads in.357 magnum. I sure lots of older manuals out there have those loads listed.

I also had an older Sierra manual with .44 magnum loads that were probably 25% over the powder manufacturers current data...and this was not "Ruger Only" info, either. Even if you started 10% under you would produce an overcharge. That manual is now in the landfill.

The point is, for new reloaders, it's best for them to start with the newest manual they can find and fresh components.
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Old October 14, 2012, 02:08 PM   #22
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When I first started reloading, I ran into this as well.
Sierra's manual in particular is very conservative- I forget the caliber, but Sierra's MAX load for the MK bullet I was using was less than the MIN load listed by Hodgdon (Varget) for the exact same bullet.

I use the data provided by the powder manufacturer whenever possible...
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Old October 14, 2012, 02:48 PM   #23
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I don't understand why one would want to use old information or components.

To save a nickel?

Pennies spent on information are almost always wisely spent.
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Old October 14, 2012, 03:41 PM   #24
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Quote:
I don't understand why one would want to use old information or components.

To save a nickel?

Pennies spent on information are almost always wisely spent.
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Agree with that. A gun blowing up in your face is no joke.
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Old October 14, 2012, 06:48 PM   #25
wncchester
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No manual is 'in-date' for any rifle except the one used to develop the listed data. That's why it's important for us to follow the one instruction that actually matters, "Start low and work up ....." etc.

It's possible. For example, Alliant now says NOT to use Blue Dot for .41 Magnum and certain loads in.357 magnum. "

And what part of "RIFLE" does that apply to?
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