Powder for 357 Magnum

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crazyjake

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Researching powders for 357. Loading for Chiappa Rhino 40DS. Using extreme 158gr SWC. Have narrowed it down to 3 powders: 2400, AA No7 and Blue Dot. All load data I've found has been based on 6,8 or 10 inch barrels. What differences could I expect in velocity and pressure in the shorter barrel. Thanks for any help in advance.
 
Welcome to TFL.

I'm curious why/how you've narrowed it down to the three propellants mentioned? Of those three, AA#7 is the obvious choice to me. 2400 is a bit slow for the barrel length (4"? . . . correct me if I'm wrong); and Blue Dot is - well - Blue Dot.

If I was the one in this situation, I'd go with Power Pistol. It's the correct burn rate for the application, in my opinion, at least. AA#7 and Blue Dot are okay too; but they'd be a bit . . . thrusty. And 2400 would be very flashy with lots of thrust recoil - it's really better suited for longer barrels.

Generally - and there's a lot of variables - you'll give up about 50 to 75 f/s in velocity from a 6" to a 4" bbl. And about another 70 from 4" to 3". Going the other direction, anything more than a 6" barrel yields diminishing returns. The barrel/cylinder gap delivers and increasing velocity penalty as the barrel lengthens.

I have 357 mag 686's in 3", 4", and 8-3/8" bbl lengths. The 8" bbl rarely delivers more than 100 f/s than the 4". And actually delivers less velocity in many lighter 38 Special loads.
 
I would also do some more looking. I use a fair amount of 2400 but it is flashy even in longer barrels and performs better in mid range to hot loads, in my experience. A lighter load of 2400 produced the only sqib I have ever loaded. I tightened the crimp and fixed the problem.
 
Of the powders listed I would use Aa7. ..I have have used 700x with good success in short barrel 357....won't provide max velocity, but burns well and consistently....
 
Looking through the Sierra, Nosler, Lee and Pet Loads books was looking at accuracy, velocity and pressures. Wanting to keep case volume near 80-90%. Some of the other powders mentioned in the manuals are hard to get ahold of yet. Hadn't looked at flash yet. Barrel location on the Chiappa (bottom of cylinder) has reduced muzzle flip and recoil. Have the Blue Dot but don't use it much anymore.
 
I have loaded and shot 2400 in short barreled 357. Expect a flame of no less than 2 feet.

Don't get me wrong, because I like 2400 in several calibers.

Try your AA #7 and forget the Blue Dot.

AA #9 is also good if you run across some.
 
Today I'm mostly using AA #9 in my 357, with the Xtreme 158 SWC, but have also used AA #7 with good results.
My pet loads are #9 @ 11.7 gr shooting for accuracy in my GP100, and #7 @ 10.6 gr , which is a hot load, with fair results.
Remember that the Xtreme 158 SWC are not the 'heavy plate' variety like their 158 HP's, and are better shot at moderately lower velocity for the 357 magnum.

After years of trying so many powders, AA works the best, and meters the best for me. But then I only shoot for steel and paper targets.
 
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My 4" GP-100 does best shooting 158s over AA#9, but H110 and 300-MP do well also. With 125s, 300-MP is the only powder that matches commercial 125 defense loads in mine.
 
It has been years since I loaded #7, and don't remember any adverse results.

For myself, I choose the 2400 of the choices listed. I do this because I load my 357 magnums for both lever rifle and revolver, and I find that it performs very well in the 20" rifle. It performs as well as I can shoot it in the revolver.

But then I like what I call versatile powders... those which can be used in a number of applications. I can use 2400 in 32-40, and it loves the stuff, in 357 magnum, 44 magnum, and in 30-30 cast bullet loads.

I think that Chiappa looks super cool. I considered it for awhile when I chose instead the S&W L-Comp.
 
I normally run H110, but I've also had good luck with cast and blue dot in longer barrels. A lot of folks will steer you away from Blue Dot, but it's worked well for me.
 
No love for 4227, huh?

As for AA#7, my Hornady #4 Manual says that AA#9 will get you faster, but I have never tried it...

I have tried 4227 and H110, and like both in .357 for mag loads...
 
Velocity: Blue Dot and AA#7 will be a bit faster than 2400 with B.D. & #7 pretty close to each other.

Behavior: Blue Dot gets 'Spikey' in the pressure curve; when you hit max you hit it hard and fast. #7 & 2400 are much more forgiving. In my experience #7 downloads the best of the three.

In a shorter barrel, Blue Dot and 2400 will give a spectacular light show especially in low light. Some of the most brilliant fireballs I have created at an indoor range was with Blue Dot in my SP101.

For me it is #7 all the way.
 
that's funny that you recommend power pistol over blue dot, I have a jug of power pistol, went through data, and wound up buying blue dot instead, because I came to the conclusion that blue dot would make a better low level load than PP. Maybe I was mistaken. In any case, I now have plenty of blue to work with for a long time, and plenty of PP to work with as well.

If I was trying to wring every last bit of power out of it, well, it's going to be a whole new story.
 
Behavior: Blue Dot gets 'Spikey' in the pressure curve; when you hit max you hit it hard and fast.
Click to expand...

I've blown the heads clean off of cases by going a little too high with Blue Dot. :o It might be fine with jacketed bullets and staying below max. I was shooting cast bullets and never found a good load -- that may have been me rather than the powder. I finally gave up on BD and decided to burn up the last few ounces in .45 Colts, and the first load I tried was wonderful in that cartridge.

AA#7 is like Blue Dot without the drama.
 
Seriously, I think any of the powders you have will work. Which one works best for your projectiles in your gun is something you'll have to find out for yourself. As for the difference in pressure and velocity from a shorter barrel, With a revolver you have throats and a cylinder gap to consider also. The little bit of velocity lost going to a 4 inch from a 6 inch barrel(BBTI shows about 80fps with a 158gr pill) will be very similar and is unavoidable regardless of which powder you use. Focus on accuracy more so than velocity.
 
What I learn every time I buy a new powder is that every one of them can be problematic in some cartridges, and without fail, I get the one that looks real good on paper but doesn't work well at all. Got trap 100 a long time ago for .38 wadcutters, looked good on paper, but the gun looked like it had been stuck in a coal bin afterwards.
 
I've not used 2400 or AA7, but have used Blue Dot extensively. I haven't experienced the "spikiness" I've read about on the internet, but it performs a little better and much cleaner than Unique with 158gr SWCs full power loads. I'm shooting from a 6" GP100. It does give a nice white flash. If you have some, give it a try, and see if you like it. It's not what I would suggest to go out and buy just for .357, but if you have it, it works pretty good.

Alliant posts warning about using it with 125gr bullets for reasons yet unknown.

From the powders I have used, if you were going for something versatile for a wide range of 357/38 loads I'd suggest Unique. If you are looking at something specifically for full power performance, you have to go to 110/296, MP-300 or 4227 to really get there.
 
regardng blue dot, I found a new one from accurate callled true blue. Didn't read up a lot, but it seemed to be a blue dot equivalent, maybe. Anyone used it?
 
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