Max Loading for .357 Mag with 2400

[pasound]

Years ago, I basically only shot magnum cannons (the early 80's - younger and dumber). I used 12.1gr of 2400 with a 158gr SWC in my 357 for targets, and 15.3 with a 240gr SWC in 44 for the same. All shot in Rugers. Fireball/cannon rounds were every 50 out of 200 target rounds, usually 2+ grains more powder each. Glad they were Rugers. Basketball sized fireballs are amazing to see.

My Smiths were 38's. No power rounds in them.

 

[Alk8944]

Per Phil Sharpe the original factory load was 15.3/2400. I have seen up to 16.1 gr. but the 15.3 has given me 1520 FPS in the three 8 3/8" Model 27s I have owned, which is the published velocity of original Winchester factory loads with the Sharpe designed 158 gr. LSWC bullet. The bullet I generally use is Lyman 358156 LSWCGC with Saeco Green lube. No leading and they all shot like a rifle. I can see no reason to exceed 15.3 grains for any use.

 

[rwsmith]

Historically......

I had not loaded .357 Mags for a long time until a few years ago. I only had 158 grain lead bullets on hand, in checking the manuals there was quite a difference between max loads for that bullet, all the way from 12.5 to 15.5. That is quite a spread, so I started at 12.5 and worked my way to 14.0 grains of 2400. I stopped there as it had enough fire, and all the cases fell out of the chambers. Nice to see that others have found 14.0 grains to be about right.

...I've BEEN up to 15.5, but started having opening/extraction problems and pretty much did what you did. My everyday load is 12.5 and my practical max is 14.5 gr. I have a 686 that has had the 'M' work done on it, but I don't want to take a chance on bending the crane or messing up the gun in any way. Besides, I don't enjoy shooting the hottest loads quite as much as I used to.

 

[Forrest r]

You want real answers, get a Garmin. $600. Until then, everybody is just guessing.

The reloading manuals will get you close, but that’s about it.

A ya ok,

I have a chronograph & that's what it gave me (1200fps) for a 50-shot string.

Could my chronograph be wrong???? Absolutely!!!

But I did compare it with a friends when I 1st bought it. Tested 10/15? different loads over both chronographs. Never saw any issues.

 

[Yendor357]

Forrest, I was answering the original poster’s question. If you have a chrono and use it, you’ve gotten it figured out.
Now if we could just get you to use one question mark and one exclamation point, you will have achieved true enlightenment.

I’ll bet a lot of reloaders without a chronograph would be surprised with the initial results, and would be making powder charge adjustments.

 

[mtgianni]

Max loads are best achieved with MP 300 powder and a 180 LBT WFN bullet.

 

[gwpercle]

357 Magnum , Ruger Blackhawk , 6 1/2" bbl.
158 grain Jacketed HP SWC
pet hunting load ... 14.0 grs 2400
This load is slightly below maximum gives me the best accuracy and is right at 1200 fps velocity .
Hope this helps ... Load Safe,
Gary

 

[loc n load]

MAX load for me with 158's is 15. of 2400.
I have shot this is in my K, L & N frame Smith's.
My everyday load, is 13.5 of 2400 with the same bullet weight.

 

[Nevada Ed]

Back in the day, when I had Speer SJHP bullets and wanted just a little more fps
out of my loads.........

I would put a heavy crimp on this bullet or a even Heavier crimp on my all lead bullets
to increase the fps a little bit, but it also increased chamber pressures.
so be very careful, if you try this.

Sometimes it will work, some times the accuray on the target goes down hill.

Speed it not always your friend.

 

[M29since14]

I’ve used 13.0 grs. 2400 with any ~160-170 gr. lead bullet and standard primers for a long time and have always been pleased with accuracy. I consider that a “full charge” .357, but not a “maximum” load. Since I use in it K-frames, in addition to L- and N-frames, I’d rather have something a little easier on the guns, and I prefer one load I can use in all of them.

I’m down to about two pounds remaining of my last batch of 2400. My thought is what to use next? That’s a problem I haven’t considered in about forty years now. In addition to working well, 2400 was always available and reasonably economical.

 

[cowboy4evr]

Not trying to hijack the thread , just thought I would mention as a replacement for 2400 try Accurate #9 or Accurate 4100 / Ramshot Enforcer . Those last 2 are the same .
#9 is a touch faster burn rate than 2400 , 4100 / Enforcer is just a bit slower . I've used both a fair amount and pleased with both . YMMV , Regards Paul

 

[rwsmith]

My .357...

...is a 686 with a 6" barrel and Hogue grips.

 

[alwslate]

I’ve used 13.0 grs. 2400 with any ~160-170 gr. lead bullet and standard primers for a long time and have always been pleased with accuracy. I consider that a “full charge” .357, but not a “maximum” load. Since I use in it K-frames, in addition to L- and N-frames, I’d rather have something a little easier on the guns, and I prefer one load I can use in all of them.

I’m down to about two pounds remaining of my last batch of 2400. My thought is what to use next? That’s a problem I haven’t considered in about forty years now. In addition to working well, 2400 was always available and reasonably economical.

I prefer a velocity of 1,200 fps with a 158 gr cast SWC out of a 4" N frame these days to maximum loads. 7.8 grs of Hodgdon Longshot with a Winchester SR or SPM primer and a good roll crimp on the bullet chronographs at exactly 1,200 fps out of my 4" 27-2 and is more pleasant to shoot compared to larger charges of 2400.

 

[cowboy4evr]

I watched a video , a guy using 2400 , 158 gr bullet from a gp100 , 4" barrel . His 13.0gr load averaged 1235 fps. The 13.5 gr load averaged 1265 fps , the 14.0 gr load averaged 1285 fps . The extreme spread on all three loads was usually between 40-50 fps .
I realized no two chronographs agree , No 2 guns will agree and then of course we have temps , ambient pressure changes . His best accuracy and tightest group was with the 14.0 gr load . YMMV , Regards Paul

 

[AJ]

I was taught to not exceed chamber pressure. Velocity was really just something that was nice to know. Not exceed the max chamber pressure while finding the most accurate load was the object. Am I wrong?

 

[pbcaster45]

I'm down to my last 10 oz. of Hercules 2400 - this is the most I ever loaded in my 6-inch Colt Python.

Bullet: Lyman #358156 158 gr. SWC-GC (.358)
Powder: Alliant 2400 14.6 grs.
Primer: Winchester Small Pistol
Case: Winchester Nickel
Comments: Average velocity 1357 fps

 

[ruggyh]

You want real answers, get a Garmin. $600. Until then, everybody is just guessing.

The reloading manuals will get you close, but that’s about it.

Sorry not.
A chronograph only gives you velocity.

Max load is about pressure- if you want to know the peak pressure you need to pressure test, not something the typical hand loader does.

A good reason to have a loading manual with pressure data included. This will give you a reasonable idea of what you can expect.

A reminder

Pressure data is about the cartridge not the gun.

Velocity can vary between guns to a number of tolerance issues- lands, grooves, BC gap, throat, and barrel length..

Apologies to AJ for getting a little of track.

 

[6GUNSONLY]

I shoot mostly cast 158-173 grain SWC and go from 13 or 13.5 with the heavies to 14 with 158s. But also shooting a lot of AA9 these days.

 

[daverich4]

13.5 of 2400 or AA#9 under a Hornady 158 gr. XTP works well for me. I personally prefer AA#9 as the performance is basically the same without all the drama.

 

[oldman10mm]

M28, Rem 125SJHP, 2400. A frame capture from when I was video recording muzzle blasts.