Conflicting load data

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buford1

New member
Speer # 10
158 gr bullet
max=17.8=1326 fps
min=15.8=1224

Speer # 13
158 gr bullet
max=14.7=1185 fps
min=13.2=1089 fps

What gives here have been using 16.8 gr of win 296. No signs of high pressure.Min load of book #10 exceeds max load of #13. Whats going on here which book should I go with,or should I average between the two.?
 
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Mike Irwin

Staff
Could reflect a couple of things.

Changes in powder formulation between the editions.

Speer's own findings based on their equipment in their lab using their components on their time.

Fear of lawyers.

What do your other loading manuals say?

You do have other loading manuals with which you compare your loads, correct?
 
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buford1

New member
The speer # 10 used a ruger security six and the speer #13 used a S+W mdl 19. The only other loading book I have is the lyman 47 edition and it doesnt show winchester 296 powder. The strange part is the data between the books is so far off that i checked the data for 44 mag the diff is 2 tenths of a grain. Why is the 44 data close and the 357 so far off?. I was going to buy the hornaday loading manual but it only deals with hornaday ,products. useless to me . I figured 3 loading books would be enough information. I will say this, my lyman book seems to undercut my older speer #10 book with rifle loads .
 
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Blue Duck357

New member
Same deal with 125's

With all the warnings I recieved on not going below the reccomended load with 296, the Speer #10 list 19.6-21.6 gr range for a 125 grain bullet, while the Winchester website list 18.5 as the only charge weight for the same bullet. Your either overloaded on one source or underloaded on the other:confused:

I'd really like to know myself if it's an increase in burn rate over the years, a lawyer thing, or just a general trend to make this fine round meet the needs of the riboflavin framed guns that weigh less than a "petite" steak at Outback.
 
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stans

New member
It could be a change in burning rate, but I tend to doubt it. I think the downloading of cartridges is born out of fear of litigation, especially since there are so many old guns out there that have been shot nearly to death. You might be surprised at the capabilities of a modern, new gun, such as a Ruger GP-100.
 
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Mike Irwin

Staff
Well, as I noted, it could be a lot of different things.

The bullets could have been harder, and given higher pressures, in the 13th edition.

Little changes can make HUGE differences in pressures.

The best thing to do is invest in another loading manual, one that shows 296, such as one of the "One Load" books, which compiles data on a single cartridge from all available sources.

Another good thing to do is to go to the manufacturer's website and download their powder manual. In this case it's www.winchester.com, I believe.

Their reloading manual can be a little hard to find, but search for it, it's there.

All a loading manual does, though, is to tell you what ONE source found using their components at one point in time. Reloading manuals can't cover all eventualities. That's why you see differences in the recommended loads. And yes, it can be startling to see one book show a recommended load that is significantly higher than another one.

That's why you should always start in the low to middle range for the load given, and slowly work your way up towards full power.
 
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cheygriz

New member
That's why I have, and use, Lyman, Speer, Hornady, Sierra, Accurate and Hodgdon.

Whenever starting to work up a new load, I average the starting and max charges from at least four different manuals to extablish a starting load.
 
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popbang

New member
"Many of the handgun loads in this manual were developed using modern piezo-electronic transducer equipment at CCI's Quality Assurance facility. In the past, all handgun loads were developed using copper crushers. There are some differences in crusher results compared to transducer results that you should understnad." Speer Reloading Manual #13 page 445

"However, some loads for the 357 Magnum are definitely lighter."
Speer Reloading Manual #13 page 445

"This difference means many of the 357 Magnum loads are less than shown before, although the slowburning propellents such as 296, H110, and VihtaVuori N110 gave very good velocities." Speer Reloading Manual #13 page 446


Hope this helps. Straight from the horse's mouth.
 
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Gary H

New member
Why don't you ask them and then post the answer here? They are the ones that would know the answer. We just guess.
 
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braindead0

New member
Somewhere, sometime ago.. all the reloading manuals started basing their loads on well below SAAMI max pressure levels for .357. Form what I've heard, the current Accurate Arms manual is the only powder manufacturer to have full power .357 loads (47,000CUP I believe).

Much of this is 'what i've heard', but I have verified with my hornady and speer manuals, compared to the current AA manual... which lists much hotter loads.

I have a feeling (and I could be wrong of course) that somewhere along the line a bunch of really cheap junky .357's were being produced and the powder manufacturers got paranoid.
 
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WESHOOT2

New member
FACT

Lawyers do not develop load data.


Please accept the following as true: "......in MY gun......" and "......but NOT always......"
Clear?
 
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Bogie

New member
W296 and 125 grainers in the .357 magnum:

Start at the minimum load for YOUR bullet, as published in the latest edition of your bullet maker's loading manual. If a 296 load isn't published by your bullet maker, start with the minimum load that you can find.

Use magnum primers.

Crimp the load VERY well. Use uniformly trimmed brass to assist in this (one of the few times I will bother trimming pistol brass.

Work up slowly - a tenth of a grain at a time. Keep an eye out for pressure signs.
 
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Clark

New member
I have overloaded 357 mag 158 gr loads to see what would happen:
AA#9... cases stick
H110 / W296... primer looks melted
LONGSHOT ... cylinder splits and top strap breaks

It takes more to make a magnum small pistol primer look melted than a plain small pistol primer. The magnum primer can also raise pressure like an extra grain of powder.

LIL'GUN is better for 158 gr 357 mag.
 
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