unburnt powder with 2400 in .357


August 22, 2011, 01:41 PM
Most of the load data I've seen states that mag. primers are not required for 2400 loads in magnum revolvers.

But I get what seems to me like a lot of black granules on the shooting bench when I shoot my .357 mag loads with 2400.

Will switching to mag. primers (and backing off and re-working up my loads) give more complete powder burn?

Just as an aside, I've been reading up on 9x23 WIN lately and was surprised to read that guys out there who seem to be in the know are using small rifle primers in that cartridge. Has anyone heard of using rifle primers in other pistol cartridge applications?

I'm not about to experiment with anything that's not well docuemented.... and am hoping it is "safe" to at least ask the question and seek out references.

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August 22, 2011, 03:08 PM
What is your load data?

2400 will not burn clean in reduced load applications, regardless of primers.
At full pressure, it does pretty well.

If you are not loading pretty close to the max pressure with 2400, you need to switch to a faster powder like Unique, etc.

The black grains you are seeing are just powder "skeletons" or the remains of the grains that burned.
I'd speculate if you collected up enough to try burning a pile of them, they are already burned and won't burn any more..


August 22, 2011, 03:14 PM
My general purpose load in 357 is 12.5 grs. of 2400 with a 158 gr. cast bullets,as rcmodel mentioned your going to get some of those powder skeletons left in the pistol bore. I love 2400 it meters well and I use it for both rifle and pistol loads.

August 22, 2011, 04:15 PM
While not as pressure-happy as H110 and 296, 2400 likes to be run near full steam. If you're getting a lot of what looks like unburned powder, up your charge.

August 22, 2011, 04:47 PM
As already mentioned, 2400 isn't as slow burning as H110/296 but it does need to be within listed data range to perform efficiently. I've not seen any 2400 data for the .357 mag. that dictates a mag. primer, so I would probably not switch primer's.
I load with H110/296 exclusively and can attest to the fact that powder charges near or below the minimum listed data doesn't perform efficiently, and will produce powder skeletons. You need more pressure to reduce those if you are in fact loading below or near the botton of the data.
Give us the load your using at this point so we can try to more accurately diagnose the cause of your concern.

August 22, 2011, 04:51 PM
Use 296 - it works best as a near max loading - results are very good with Hornady 140 & 180 XTP's. I use a 6" GP100. 18 & 13 grains respectively.

Master Blaster
August 22, 2011, 08:06 PM
also make sure you have a good roll crimp, poor crimp can cause reduced pressure and incomplete burn.

August 22, 2011, 08:35 PM
here's the load...

158 gr. Zero JSP
13.8 gr. A2400
Win. std. small pistol primer
1.58 COAL
Firm roll crimp
Fed. .357 mag. brass

according to my notes:
1. load is pretty warm, just shy of factory Federal 158s
2. load is more accurate than my attempts at downloading rounds (11 gr. A2400)
3. lot's of unburned powder

I've never heard of powder skeletons before. They were black sphears.

I'm shooting a 20 year old, lightly used and well cared for Taurus 689 with a 6.5" vent rib barrel.

Steve C
August 22, 2011, 08:38 PM
You can drive pressures up using magnum primers with 2400. Not that they can't be used, but the load needs to be worked up and you're likely to see pressure sign before reaching the maximum load in the manuals. Currently Speer specifically recommends standard primers only with 2400 and notes pressure problems with mag primers if you use their data developed with standard primers.

I've seen pressure signs, pierced, cratered and leaking primers when using CCI magnum primers and approaching 14.0 grs of 2400 with 158gr jacketed Speer bullets many years ago (1975).

August 22, 2011, 09:07 PM
Im glad this thread came up.

Im using 11.0 Grains under a 158 Gr Plated FP. At least now I know to expect unburnt powder seeing as I used a SPP rather than a SMPP. Im thinking the roll crimp I gave it should help it tho.

Sorry, Don't mean to hijack your thread.

August 24, 2011, 10:11 AM
oops... meant to start a new thread with this one....

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