Author Topic: .357 Magnum Load Data  (Read 3380 times)

TXCOONDOG

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.357 Magnum Load Data
« on: August 12, 2016, 07:40:01 AM »
I have a GP100 .357 in 6" and not sure which powders and primer to reach true mag velocities (match Buffalo Bore):

XTP bullets:
125 gr 1675-1700fps
158 gr 1450-1500 fps
180gr 1325-1360fps

I have the following powders but not sure if these will get me there:
Tightgroup
Longshot
Blue Dot
LIL'Gun
AA# 9

The_Shadow

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Re: .357 Magnum Load Data
« Reply #1 on: August 12, 2016, 02:27:41 PM »
If you get the chance look at the Hodgdon data they offer it is good stuff and still includes the pressure values for their published loads. :D

Here is some Alliant 2006 data
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oldman10mm

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Re: .357 Magnum Load Data
« Reply #2 on: August 12, 2016, 02:40:36 PM »
Your listed powders-burn rate applicable for 357M full power loads
-Tightgroup-way too fast to use
-Longshot-slightly too fast
-Blue Dot-of the powders you listed probably the best
-Lil'Gun-too slow
-AA#9-too slow
S&W 1006
S&W 610 6.5"

TXCOONDOG

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Re: .357 Magnum Load Data
« Reply #3 on: August 12, 2016, 04:42:03 PM »
I have to pick up some primers so I'll pick up some 4227.

I was planning on starting with 9 grains of BD and the 158 gr XTP and going from there.

Thanks for the input
« Last Edit: August 12, 2016, 04:54:22 PM by TXCOONDOG »

oldman10mm

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Re: .357 Magnum Load Data
« Reply #4 on: August 12, 2016, 05:17:01 PM »
4227 is a little too slow burn rate to attain the velocities you want,you'd probably have to use highly compressed loads. probably also,with 4227,you'll need a very heavy crimp to assure completely burning all the powder.
« Last Edit: August 12, 2016, 05:23:36 PM by oldman10mm »
S&W 1006
S&W 610 6.5"

The_Shadow

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Re: .357 Magnum Load Data
« Reply #5 on: August 12, 2016, 09:01:43 PM »
You will want a good crimp rolled into the cannelure of the bullet...Because that is why they have a cannelure is to allow the rolled crimp a place to fold into and secure the bullet...  The slower powders need secure crimps to allow for a full ignition.

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Intercooler

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Re: .357 Magnum Load Data
« Reply #6 on: August 13, 2016, 08:21:15 AM »
Did you check out the .357 Magnum sheets?

All the best and worst in every weight. You should find something there to set your hair on fire  ;D

https://docs.google.com/spreadsheets/d/12cjblt0pDB-csBqvoDoCLQH_SLRlUNLHkBVDxge1O2k/edit#gid=4

TXCOONDOG

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Re: .357 Magnum Load Data
« Reply #7 on: August 13, 2016, 03:54:38 PM »
I got to sorting through my brass and found that I only have 50 pieces (300 .38 special) of .357 mag brass so I placed an order with Starline.

Once I receive the new brass, I'll start working on load development and post up my results.

I greatly appreciate the input all.

TXCOONDOG

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Re: .357 Magnum Load Data
« Reply #8 on: August 20, 2016, 08:50:46 AM »
Ruger .357 , GP100, 6" Model 1707

I'm reaching the velocities in the Lyman #49 manual. However, I'm finding unburnt powder on the bench and on top of my chrony so I'm guessing that I need a tighter roll crimp.

Note: I matched my crimp (mine actually looked more consistent) to some Hornady factory loads.

No signs of pressure

Bullet: Hornady 158 gr XTP HP
Case: Starline 1.285"
Primer: WSPM
Powder: Blue Dot 9.0 grains
O.A.L: 1.590"
Velocities: Average 977 fps
Five shot Group size at 25yards: 1.25"
.........................................................................
No signs of pressure

Bullet: Hornady 158 gr XTP HP
Case: Starline 1.285"
Primer: WSPM
Powder: Blue Dot 9.5 grains
O.A.L: 1.590"
Velocities: Average 1057 fps
Five shot group size at 25yards: 1.25"
..........................................................
No signs of pressure

Bullet: Hornady 158 gr XTP HP
Case: Starline 1.285"
Primer: WSPM
Powder: Blue Dot 10 grains
O.A.L: 1.590"
Velocities: N/A
Five shot group size at 25yards: 1.35"
..........................................................................
No signs of pressure

Bullet: Hornady 158 gr XTP HP
Case: Starline 1.285"
Primer: WSPM
Powder: Blue Dot 10.5 grains
O.A.L: 1.590"
Velocities: Average 1185 fps
Five shot group size at 25yards: 4 @ 3/4" & 1 flier 1.50"

 Note: When I started seeing unburnt powder and extreme velocity spread of 110 FPS
« Last Edit: August 20, 2016, 08:52:39 AM by TXCOONDOG »

The_Shadow

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Re: .357 Magnum Load Data
« Reply #9 on: August 20, 2016, 11:24:56 AM »
Yes a good crimp is needed but with Blue Dot you need a saturated loading...
My personal loading would scare some, I suppose...I have shot these at 11.5 grains

Lyman 358429 Keith Style SWC 165 grain
Caliber – 357 Magnum
Powder- BLUE DOT 10.5grs
Case – Mixed
Primer – CCI  550
COL – 1.620”   Sized .358”
Velocity – 1280 – feet/per sec  6” Barrel

Speer #9 shows the 158 grain JHP and JSP being used with Blue Dot  Ruger Security Six 6"  1:18.75" twist
11.0 @ 1149 fps
12.0 @ 1264 fps
 
Speer #10 shows the 158 grain JHP and JSP being used with Blue Dot  Ruger Security Six 6"
12.0 @ 1231 fps
13.0 @ 1328 fps

Speer #11 shows the 158 grain JHP and JSP being used with Blue Dot  Ruger Security Six 6"
11.0 @ 1185 fps
13.0 @ 1349 fps

This is the Speer 180Gr Silhouette gas checked I load these with 11.0 grains of Blue Dot here is my results...
357mag RCBS 180gr Gas Check Silhouette COL – 1.660” (loaded i the normal cannelure)
Bullet is 0.8330” long  (will not fit some cylinders loaded in the normal cannelure)
Inside the case is 0.4600”
Outside the case  0.3730”


Velocity 1320 feet/per sec my S&W Mod 19 6" 1:18.75" twist
Intercooler's Ruger 4" GP100 @ 1237, 1234. Average = 1235.5 FPS/ 610 LBS.
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TXCOONDOG

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Re: .357 Magnum Load Data
« Reply #10 on: October 17, 2016, 04:38:52 PM »
I went to a Redding profile die and opened the flash hole .001". All my unburnt powder issues went away which improved the ES and SD (10-12).

After trial and error with various powders, OAL, primers, etc; I settled on the following load for hunting (for now):

Bullet: Hornady 158 gr XTP HP
Case: Starline 1.285"
Primer: WSPM
Powder: 300-MP 20.5 grains
O.A.L: 1.575"
Velocities: Average 1626 fps
Five shot group size at 25yards: 5 @ 3/4"

Note: Started to see some pressure signs.

1.48" group at 50yds.





Cast my first .357 Magnum boolits using clip on wheel weights mixed with 2% tin. The mold is a Lee six cavity .358" 158grain SWC.



Air cooled boolits have a BHN of 13.4 and the water dropped (cooled) have a BHN of 19.3 after 7days.

I powder coated the boolits using Eastwood Ford light blue powder coat baked in a toaster oven at 400 degrees for 20minutes.

Note: All boolits had to be resized to .358" because the powder coating added .003-.005"




Powder coating hammer smash test to see if the coating would flake/peel:




Now time to start working up target loads for my GP100.

 



« Last Edit: October 17, 2016, 04:46:44 PM by TXCOONDOG »

ss30378

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Re: .357 Magnum Load Data
« Reply #11 on: November 28, 2016, 06:49:08 AM »
Wow, went from "normal-ish" 357 watered down loads to a 927 ft lb monster load!  Awesome!  I'm starting to really like 300mp, it seems to get better once you get into the heavy for caliber bullets (180+ in 357, 300+ in 44, 340+ in 454) high resistance bullets it begins to get happy.  More velocity and less pressure than h110 or lil gun.    I learned a heavy crimp is needed to get it to burn completely as well, much more so than h110.

Randominator

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Re: .357 Magnum Load Data
« Reply #12 on: December 03, 2016, 07:05:03 AM »
I was never able to achieve those velocities in a revolver with jacketed bullets without pressure signs.  I have pushed cast bullets to 1450 fps. and they shoot really good.  W296 has been the best powder for me in a 357 with all bullet weights down to 125 grains.

I took this 11 point whitetail last month with a Dan Wesson 357 using a 158 grain Hornady JFP traveling at 1330 fps. from a 8" barrel.



I recovered the bullet in the offside shoulder.  It weighed 140 grains.

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bobonit

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Re: .357 Magnum Load Data
« Reply #13 on: January 01, 2017, 02:34:32 PM »
I went to a Redding profile die and opened the flash hole .001". All my unburnt powder issues went away which improved the ES and SD (10-12).

After trial and error with various powders, OAL, primers, etc; I settled on the following load for hunting (for now):

Bullet: Hornady 158 gr XTP HP
Case: Starline 1.285"
Primer: WSPM
Powder: 300-MP 20.5 grains
O.A.L: 1.575"
Velocities: Average 1626 fps
Five shot group size at 25yards: 5 @ 3/4"

Now time to start working up target loads for my GP100.

I bought some 300-MP a while back and haven't tried it yet.  I will have to load some 158's with it to try in my Dan Wesson.  Thanks for the report.

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Re: .357 Magnum Load Data
« Reply #14 on: February 13, 2017, 07:31:17 AM »
My old go to powder was Winchester 296. But after Obozo got elected and caused the powder shortages I had been forced to use Unique or Blue Dot since I had stocks of both of them. I finally did get an 8 pound jug of the Winchester so I am back to using it.
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