Conflicting 357 magnum data?

[crimsoncomet]

Hey guys,
Just entering into the revolver world lately. I have moslty loaded for gas guns and semi auto pistols in the past. I picked up a S&W 686 the other day along with powder, magnum primers and plenty of bullets (big sale). I have rcbs dies that have been sitting in a drawer for the past year and a half and i also picked up a lee factory crimp die (dont know if it is necessary).

I dont want to beat this nice gun up or getting flame cutting with heavy loads with really slow burning ball powders, so I try to stay away from really heavy charges of powder.

Sorry for the rambling. Now to the question. I loaded up some 158 grain sierra JHC's with 2400 powder and SP primers. The firing pin marks on the primer seem very deep. One looks like it is on the brink of cratering. Here is my load.

158 sierra JHCs w/ 12.5g of 2400 w/ SP primers- primer had deep firing pin marks.
158 Speer JSP with 14.0 of 2400 w/ SP primers- these primers looked normal.

The only thing i can think of, is that the 12.5g load is to light for standard primers. Would this make that much difference.

Speer states the the starting weight with this bullet 13.8g maxed out at 14.8 with SP primers. Lyman states 11.3 maxed out at 14.9 with magnum primers. Nosler states 11.3 to 12.3 with magnums.

Why is this data so conflicting with the start charges and the use of magnum vs. standard primers? It seems that 12.5 is on the low side. But is it just on the low side with standard primers and not magnum primers? Speer only uses magnum primers for certain powders, while lyman uses them for every powder. Is this why Speer's starting weights are higher?

Thanks in advance.

 

[Hondo 60]

Well I think the start of your issue is that Alliant doesn't recommend 2400 for your gun.

Under .357 magnum they have data for 5,7,9 & 4100. No data for 2400.
Perhaps you might consider using a different powder.

I know, I know, that doesn't answer your question. I'm sure someone much more knowledge than I will post & really answer the question.

Good luck!

 

[m33p0n3]

Well I think the start of your issue is that Alliant doesn't recommend 2400 for your gun.

Alliant data I have from their website shows a max load of 14.8 grains of 2400 for a 158 gr Speer GDHP.

 

[Bula]

I shoot alot of 2400 from my .357's. 2400 is my absolute favorite mag level powder in .357, .44 mag and .45 colt. In .357 I load 125 gr, 158gr, 162 and 173 Keiths. I have never used magnum primers-ever. Using standard primers, neither of your loads is above pressure limits. Read less into your primer dimple and worry more about sticky extraction. Also, verify your brass doesn't have loose primer pockets (ie. primer seating WAY to easily). Flame cutting isn't really an issue with the 158's, I shoot very few 110-125g jacketed pushed hard. Verify OAL as well. I used to shoot jacketed pushed hard, but soon realized that paper didn't need 1400 fps. I mainly shoot cast now, for a really amazing load, try a cast Lyman 358429, over 13.5g of 2400 and any non-mag small pistol primer. My 6" 686 really loves that one.

 

[USSR]

...for a really amazing load, try a cast Lyman 358429, over 13.5g of 2400 and any non-mag small pistol primer. My 6" 686 really loves that one.

+1.

Don

 

[Skip_a_roo]

Hondo is on the Accurate Powder website. Wrong "A" brother!

2400 is not going to give you flame cutting, at least at the normal 357Mag levels. There is a friend on another forum that has only used H110/W296 once, it was the ONLY time flame cutting ever appeared and he has used a BUNCH of 2400.

The primer problem MAY be because the case isn't going back to the back of the frame and seating during firing. I can assure you that your other load is!


Now, I like to use magnum primers for 2400 in the bigger magnum cases. 44Mag, and some of my 45 Colt Ruger Only loads. It just makes the numbers better across the chronograph. The SD and ES really fall when I use them. YMMV.

As for the M686's ability to handle heavy loads, FORGETABOUTIT! Unless you use a double charge of an uber fast powder, you aren't going to hurt it!

If you want a middle of the road load for the 357Mag, I would, and do, use SR4756. There are lots of loads from the days gone by that work really well in the heavy "L" frames.

I don't like light bullets in the 357Mag either. I stay at or over the 158gr for a limit. Most of my cast bullet loads develop over 1280fps from the 6" barrel M586 that I have now.

FWIW

 

[crimsoncomet]

Thanks guys.
@bula- I may try some cast bullets. Thanks for the info and the heads up. Do you get alot of muzzle flash. It seemed pretty bad.

@Skip_a_roo- That could def be the primer issue. Extraction was easy. How much H110 did he go through before he saw cutting? I heard these new 686's were tuff guns. I love it so far. I shot some 180 XTPs over 11.5 of AA #9, and that was one accurate nice shooting load. I havent chronoed it yet. I probably will next weekend. I dont plan on shooting anything under 158g. Everything i have is 158 or heavier.

 

[Skip_a_roo]

Thanks guys.
@bula- I may try some cast bullets. Thanks for the info and the heads up. Do you get alot of muzzle flash. It seemed pretty bad.

@Skip_a_roo- That could def be the primer issue. Extraction was easy. How much H110 did he go through before he saw cutting? I heard these new 686's were tuff guns. I love it so far. I shot some 180 XTPs over 11.5 of AA #9, and that was one accurate nice shooting load. I havent chronoed it yet. I probably will next weekend. I dont plan on shooting anything under 158g. Everything i have is 158 or heavier.

6 rounds! That was all! To be fair though, he was using a light bullet. 125gr I think.

 

[tactikel]

Hondo perhaps you have been at the fishfry at Casper's and have been overserved at the bar. 2400 is the finest powder for the .357 IMHO.

 

[Steve C]

14.0grs of 2400 lit by a CCI 500 standard pistol primer pushes a 158gr JHP out the muzzle of my 4" Smith 66 at 1,243 fps which is right at what one would expect from a factory load. A 12.5gr would likely be around 1,100 fps +/- a few.

Flame cutting is a result of the amount of burning gasses that are produced. The greater the charge weight the faster you will see flame cutting. Heavy loads with 2400 or H110 using lighter bullets like the 125gr will show flame cutting the quickest.. If you shoot many full magnums then you will get some flame cutting eventually. If you want to avoid it altogether just load with a faster powders like Unique and be satisfied with lower velocities closer to 1,000 fps.

 

[Hondo 60]

Skip_a_roo said: Hondo is on the Accurate Powder website. Wrong "A" brother!

Oops! OK- I screwed up! Skip is correct I was looking at Accurate powders. 2400 is an Alliant powder.

 

[Skip_a_roo]

You ain't the only one that has ever messed up!

Oops! OK- I screwed up! Skip is correct I was looking at Accurate powders. 2400 is an Alliant powder.

When I mess up, it is usually much more severe than just having the wrong powder site!