Max load for 2400 with a 158 gr. LSWC in the 357???

[Hammerdown77]

Today, I was shooting my new to me 686-1 for the third time since its purchase, and I was shooting a load with 15.0 grains of 2400 under a 158 gr. LSWC. Earlier in the week I shot about 25 of these without incident. Accuracy was decent, recoil was stout but manageable (I'm used to .44 mag).

Today, however, I had the cylinder lock up tight on me. From what I could see, it looked like the primer had flowed out around the firing pin strike enough to where it kept the cylinder from turning. With a little force, I got the cylinder open. I disassembled a few of the remaining rounds and weighed 15 grains.

My Lee reloading manual shows a max load of 15.3 grains. I've seen this in older Alliant data as well. However, their current data contains nothing for the 158 gr lead bullet. Their load data from 2005 shows only data for the 158 gr. JSP bullet, and lists a max of 14.0 grains.

Am I over the limit with this 15.0 grain load? I was seeing a decent amount of primer flow on the ejected casings, but case extraction was not sticky. I have not run these over the chronograph yet.

Locking up the gun was a bit worrisome. Never had that happen before.

 

[alwslate]

Your load is not excessive. This has long been a problem with the 357
mag. It is usually caused by a slightly oversize firing pin hole in
combination with a soft primer. Try a different brand of primer, make
sure your primers are fully seated and consider switching to a small
rifle primer. CCI SP primers have been the worst offenders for me in
this regard.

 

[BruceM]

Has the 686-1 had the recall modification done to it? Primers extrusion into the hammer nose bushing was the reason for the recall.

Bruce

 

[Skip Sackett]

Every gun is an individual. My question is this: If you had primer flow to start with, why did you continue? Good safety would have mandated that once a problem was noted, shooting those rounds in that firearm should have ceased!

I am with the too soft of primer, too large of flash hole crowd on this one. There is NO way you are going to damage that 686 with a full load of 2400, no way. Fill a case with Bullseye, might be a different story!

I use Winchester or Wolf primers for heavy handgun loads. Federals are reserved for target loads.

FWIW

 

[27 Man]

The same thing happened to me with my 6" 686 no dash with the extendable front sight. The gun has the "M" marking in the crane so it apparently was sent in at some point in the past. I also was shooting 15.0 grains of 2400 with a Lyman 358156/GC cast bullet. My primer was the CCI 550. Never had this problem before with any of my 27s or 28s with this load.Guess I will switch over to WW primers for this load. Thanks for the information.

 

[Hammerdown77]

This is great info, guys! I'm new to reloading the 357, so I was unaware of the primer flow issue inherent to the caliber; although, I did know about the recall on the 586/686 for this type of problem.

Yes, my 686-1 has the "M" stamp, so it's had the recall work done.

I was in fact using CCI small pistol primers. Sounds like I should try a different brand for that load.

I'm almost out of 2400 anyway. I've been trying AA #9 and got pretty good results with 12.2 grains, so I'll probably just stick with that for my heavier stuff.

 

[Paul5388]

The 15.0 gr of 2400 with a CCI 550 is probably an overload, since that's normally the load used with a standard primer. I've used CCI 400s for 30+ years, but I only shoot single action with my M28-2 and M66 in order to get maximum hammer strike on the primers.

 

[Peter M. Eick]

Interesting.

I only shoot out of N frames, and I believe the 686 is an L frame.

I pretty much only shoot lasercast 158's and according to their manual, 15.3 grns is max with a cci550 primer. I routinely shoot 15 grns of 2400 out of my N frames with no issues. 14.5 grns is my "plinker" load and a full 15.3 is my go to load.

Maybe your gun just can't handle a full load. It could be that or an L frame vs. N frame difference.

 

[Hammerdown77]

I am using CCI 500 primers with this load, not 550.

 

[Peter M. Eick]

Odd, Normally I would have said a magnum primer would generate more pressure than a conventional one. Interesting that in your gun behaves this way.

I am not sure what to say other you may need to back it down.

I can say that with conventional primers and 158 grn leads I have gone above 16 grns but would not do it again. I was trying to see how much 2400 it would take to get a 158 to go 1550 FPS out of my 8 3/8" pre-27. My gun would take it just fine and extraction was easy but I worried I was pushing my luck with a nice 1950's S&W.

 

[DGNY]

Thanks for your post. I recall the high loads of 2400 recommended years back [and some now] and have not personally had success with more than around 14.5 gr with a 158 lead bullet, despite the manuals and 'what Elmer did'. This is in a range of Ruger Blackhawk [OM and NM] and S&W K,L and N. And no knock on any prior posters here...

I wonder if greater case thickness among brands and a long bullet base-to-crimp groove dimension will combine to reduce effective case capacity and enhance such primer flow? Also maybe a bit of endshake allowing primer extrusion and flow upon reseating.

Best,

Dyson

 

[Bill22250]

Switch Primers

really no big deal, change primers, reduce your load and work back up.

 

[K&Nframe]

All guns are different. This is the reason we work up loads instead of going right to max loads. It sounds to me like the load is too "hot" for your gun. What works in one 686 may not work in another. Back off to 14.5 or so and work it back up .1grn at a time until the problem reappears then back it off .1grn.

Kevin

 

[ArchAngelCD]

While you can use a magnum primer with 2400 it's really not needed. As for that 15.0gr charge, while I don't think it's overpressure especially with a standard primer I've found I get better accuracy when using a charge of 14.5gr under a 158gr LSWC bullet. You might want to give that charge weight a try and see if your accuracy improves. (since you said accuracy was only decent)

 

[TSQUARED]

Every gun is an individual. My question is this: If you had primer flow to start with, why did you continue? Good safety would have mandated that once a problem was noted, shooting those rounds in that firearm should have ceased!

I am with the too soft of primer, too large of flash hole crowd on this one. There is NO way you are going to damage that 686 with a full load of 2400, no way. Fill a case with Bullseye, might be a different story!

I use Winchester or Wolf primers for heavy handgun loads. Federals are reserved for target loads.

FWIW

I agree. When you see a problem you do not continue using the same ammo. With most powders one is always advised to work up a load starting well below maxium and cease when one sees an issue developing.

 

[Hammerdown77]

I'll try the 14.5 grain load of 2400 with what little powder I have left. I am liking the 12.2 grains of AA9, actually. I also have a pound of AA5 I might try, although it is so fine it leaks through my Lee Auto Disk.

8.0 grains of Power Pistol also appears to be an excellent load out of this gun. I use Power Pistol for everything, so that will probably be my go-to load.

 

[Rule3]

How many of your powder "throws" have you weighed? What kind of scale?

With the Lee Disk, I have found at times a .5 to almost 1.0 gr variance with 2400. If you have yours set to what you believe is 15.0 grs you may actually be over that.

Just a thought to check out.

 

[Hammerdown77]

I have never had that much variation in throws with 2400. Granted, the actually charge thrown is not anywhere close to what Lee's chart claims, but that's why I weight the charges. I'll see +/- 0.1 grain. I'm using a Dillon beam scale. I weight 5 throws in a row last time and it was within that tenth of a grain variation.

 

[Rule3]

I have never had that much variation in throws with 2400. Granted, the actually charge thrown is not anywhere close to what Lee's chart claims, but that's why I weight the charges. I'll see +/- 0.1 grain. I'm using a Dillon beam scale. I weight 5 throws in a row last time and it was within that tenth of a grain variation.

OK, if your throws are that tight, then I want a new Pro Disk
No, the chart is only a estimate based on when they tested and what lot of powder they have.(actually mine was screwed up, I sent it back to Lee.) Seems the swivel adapter had worn a groove in the slot where the arm goes and I was getting variable throws. On the larger disks it would not completely go over the drop hole. Be sure to put a drop of lube in that spot.

I have the same balance and just wanted to be sure you checked, as you are at the high end depending on what data (manual) you look at.

 

[Hammerdown77]

I had the same issue with the swivel adapter wearing. I didn't notice it affecting the consistency for anything but the larger cavities. I'd have the same problem, the larger cavities would not go all the way over the drop hole and would leave a "shelf" where powder could remain. Got a new swivel adapter from Midway. I'll have to remember to put some Tetra or something on it, thanks for the tip.