Saturday 8 December 2012

Chronicles of working-up loads for my 357-SIG

357-SIG: A General Purpose Load: Load GP#1 .. 9.0 grs of AA #5 stays within Mfg. recommended Max Load.

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357-SIG: A Paper Target Load: Load PT#1clip_image004

Two useful loads that work for me. Load GP#1 makes use of Re-sized bullets to 0.3558” diameter.  This allows me to stock 38/357 125gr FP bullets and use them to generate loads for: 38 special, 357 Magnum and 357 SIG. A lesson from; “Lean Manufacturing – Flexible Inventory.”

Manufacturers load ranges for 357-SIG; Hodgdon and Accurate Arms .. check their web sites.imageFuture Plans:

1) 357 SIG: Next step is to Re-Size 38 Special, 158gr SWC bullets to 0.3558 and verify velocity. If all is ok this will be PT Load #2

2) 9mm Luger; develop a re-sizing process for 0.357” diameter bullets to 0.355”.

Ideas are to use a two-step process: 0.357” to 0.356”, then 0.356” to 0.355”. A one step resizing from 0.357” to 0.355” will be tried.

Outline of test plan that determined my optimal loading from me using SIG 357 Semi-auto Pistols.

The Basic plan is to use my previous load as a baseline, test number 4. Setting up these experiments is fine when you have total control, but using a public indoor range, forces one to make accommodations and concessions.

The tables chronicle the test sequences and variables of empirical data and results. The relative feelings experienced during the shooting and general satisfaction with said results, are a major factor to consider.

All range shooting is Free-Hand shooting. no pistol rest. So natural variability is built in .. My quest is to find what works for me.

Dual, side by side targets set at three distances for each test. Sig P229S – Five shots at each target. An eight by three matrix requires: 8x3x10 = 240 rounds and 8x2x3 = 48 targets. Prior to a test run seventeen round of Blazer commercial ammo was shot to warm up the pistol (when shot at different times/days) Velocity averages are 10 shots over the chronograph, prior to shooting the targets.

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Tuesday 4 December 2012

357-SIG: Bullet Prep a slightly controversial approach.

There is a veritable plethora of published Information and Data, regarding the “Bullet Diameter” best suited to this bottlenecked pistol cartridge.  Published Opinions vary. So I set about finding what works for my needs.imageHaving loaded a number of 357 SIG rounds using Bullets designated for 38 Special / 357 Magnum (.357” Dia.) with no problems, I’ve decided to experiment and find an optimum load that works for me. My guns chambered in 357 SIG (they are Sig Sauer Semi-Auto pistols) perform best using; of all things, Blazer ammo. (commercial ammo)

NOTE: Aluminum Cases are designated as a onetime use; yes some folks have reloaded them, just NOT ME So a number of empirical experiments ensued. The parameters that varied: Powder Charge, Bullet Diameter and Bullet Weight. The result is a very good load for my guns using; Bass Shell Casings and Resized 357 Bullets, propelled by Accurate Arms #5 powder.

Re-Sizing: Copper Plated Bullets.

Resizing / Swaging Cast Lead Bullets is an everyday occurrence within the reloading community. Not so with Copper Plated Bullets.  Bullet suppliers; X-TREME Bullets and Berry’s Manufacturing, are my choice.

Using: Lee .356 Lube and Size Kit. Fits standard reloading press 7/8 x14 TPI.   Purchased from Brownells; $18.99

clip_image004clip_image006 As seen in the Lee instruction pamphlet, using their sizing die is simplicity personified. 

I use a Redding T-7 press for various reloading tasks (not volume pistol reloading)  purchased from Brownells; $249.99. Cast Iron construction, easy to use compound linkage, seven station turret.Processing 1,000 bullets in four batches of approximately 250 works for me.  Keep a Clean and Organized work area. Set-up an area for overnight drying of the bullets with applied Lube.   For this type of processing I mount the press on my; general purpose, Butcher-block work bench. This provides a stable large open work space.

1,000: 38/357 Caliber, 125gr FP with Cannelure.As-Is diameter: 0.357”  Average Re-Sized Diameter: 0.3558”Batch of approx. 250+ lubed bullets await re-sizing.  Approximately 500 bullets finish off drying, after Lube removal.