Reloading The .357 SIG

Posted on: Thursday January 7, 2021
Reloading The .357 SIG
MD Smith

MD Smith


SWC= Semi-WadCutter, FMC= Full Metal Case, FMJ= Full Metal Jacket, JHP= Jacketed Hollow Point and if GC indicated, means Gas Check at bottom of lead bullet, recommended for the .357 Sig

Loads for .357 Sig:

(Note: These ARE MAXIMUM loads, you should use 10% less to start.)

(See note on Powders below or read all about various Powders.)

Bullet size is .355″ (9mm)(jacketed) in diameter. Use a .356″ for lead bullets. Federal is using true 9mm and not .38 or .357″ diameter. Due to different barrel lengths, type of bullet, seating depth, primer type and other factors, you may not get near the FPS charted. It is just a guide and the reason you should start under these charges and work up.

This is a new cartridige. Here is what the people at Accurate Arms Powder Company say about the round: “Inquiries led us to Federal Cartridge, who, at the time was the sole source of ammo for the .357 Sig. We learned that .357 Sig is basically the .40 S&W cartridge necked down to take 9mm bullets. This cartridge was developed specifically for the law enforcement market. It was intended to duplicate the ballistics of the highly regarded 125 Grain JHP .357 Magnum load as fired in a 4” barrel revolver. This, the .357 Sig basically does.

Reports from the field praise the accuracy of this round. Our No. 9 has proven to be especially well liked in this regard. This surprised us somewhat as the case is full and even compressed when using No. 9 in some loads. Which just proves that you shouldn’t put too much trust into preconcieved notions.

This is without a doubt the most ballistically consistant handgun cartridge we have ever worked with. The standard deviation for every single load developed was less than 10 FPS. The average SD was 5 FPS. This is impressive for any cartridge but especially so for a handgun. The small bottleneck and high working pressure of the round must both contribute to this amazing consistancy, but regardless the results are impressive. If you have any further questions about our propellants please call our customer service department toll free, 1-800-416-3006, 8am-4:30 pm central time.”

These are ALL MAXIMUM LOADS: Start at 10% less and work up! Caution! All Max loads generate between 36,000 and 39,000 PSI.

Bullet size is .355″ (9mm)(jacketed) in diameter.

88 grain Speer JHP (Jacketed Hollow Point)
No. 2 7.9 gr. 1,545 FPS
No. 5 11.1 gr. 1,616
No. 7 13.1 gr. 1,601
No. 9 * 15.0 gr. 1,545

* compressed load

90 grain Sierra JHP (Jacketed Hollow Point)
Bullseye 9.3 gr. 1,660 FPS
Unique 9.2 gr. 1,615
Power Pistol 11.4 gr. 1,715
HP-38 7.3 gr. 1,509
Universal 7.0 gr. 1,511
HS-6 10.8 gr. 1,634
95 grain Sierra FMJ (Full metal jacket)
No. 2 7.6 gr. 1,467 FPS
No. 5 11.0 gr. 1,572
No. 7 13.0 gr. 1,562
No. 9 * 15.0 gr. 1,530*

* compressed load

100 grain Hornady FMJ (Full metal jacket)
No. 2 7.3 gr. 1,414 FPS
No. 5 10.5 gr. 1,496
No. 7 12.2 gr. 1,490
No. 9 * 14.5 gr. 1,516*

* compressed load

115 grain Lead SWC (.356″ dia.)
No. 2 6.2 gr. 1,249 FPS
No. 5 9.0 gr. 1,319
No. 7 11.0 gr. 1,344
No. 9 * 13.5 gr. 1,430*

* compressed load

115 grain XTP or JHP (Speer or Hornady)
Bullseye 8.0 gr. 1,435 FPS
Power Pistol 10.0 gr. 1,510
Universal 6.1 gr. 1,300
HS-6 9.4 gr. 1,412
HS-7 10.6 gr. 1,420
VV N350 8.0 gr. 1,317 (Ala. Ammo Load, Very Nice)
No. 2 6.4 gr. 1,276
No. 5 9.4 gr. 1,354
No. 7 11.3 gr. 1,385
No. 9 * 13.5 gr. 1,434*
WAP** 8.7 gr. 1,400**

* compressed load
** From GUNS Magazine, not Winchester

124 grain XTP or JHP (Speer or Hornady)
Bullseye 7.0 gr. 1,320 FPS (SpeerTMJ)
Power Pistol 9.5 gr. 1,435 (Speer TMJ)
Universal 5.8 gr. 1,235
HS-6 9.0 gr. 1,339 (start with 8.0 gr.)
HS-7 10.2 gr. 1,353
H110 *** 14.0 gr. 1,385 MAX (start with 11.5)
No. 2 6.0 gr. 1,212
No. 5 9.2 gr. 1,325
No. 7 11.0 gr. 1,320 (Start with 9.5 gr.)
No. 9 * 13.0 gr. 1,387*
WAP** 8.1 gr. 1,300** (start with 7.0)
WAP*** 9.5 gr. 1,400 MAX (start with 7.0)

* compressed load
** From GUNS Magazine, not Winchester
*** Guns & Ammo Magazine (Sept. 96)

147 grain Hornady XTP
Bullseye 5.8 gr. 1,145 FPS
Unique * 5.8 gr. 1,110*
Power Pistol 7.8 gr. 1,245
Universal 4.9 gr. 1,062
HS-6 7.6 gr. 1,173
HS-7 8.4 gr. 1,173
H110*** 13.0 gr. 1,250 (MAX (Start at 11.0 gr.))
No. 2 5.3 gr. 1,061
No. 5 7.9 gr. 1,159
No. 7 9.2 gr. 1,160
No. 9 * 10.5 gr. 1,158*
WAP** 6.8 gr. 1,100**

* compressed load
** From GUNS Magazine, not Winchester
*** Guns & Ammo Magazine (Sept. 96)

These are ALL MAXIMUM LOADS: Start at 10% less and work up!

** Winchester loads from GUNS Magazine, June 1996 issue

Discussion: Bullseye is a fast burning powder and perhaps better suited to the small cases like the 9mm. It burns completely and fast. Unique is a very consistent burning powder and it is almost a tossup with the heavier bullets. Power Pistol is quite a bit slower and favored with Alliant for this magnum load of the .357 Sig.

Accurate Powder supplied extensive data for the round and also prefer the slower burning powders, even down to the No. 9. No.9 are compressed loads in most cases. It showed some of the highest speeds while maintaining some of the lowest pressures. Looking at the data, I would agree, and suggest No. 7 as an alternate, but you certainly can use No. 5 or the fastest No. 2 if you wish.

Universal, HS6, and HS7 are from Hodgdon and similar to Bullseye and Unique. HS7 is slowest of the group and takes quite a bit more powder as does No.9 and Power Pistol.

A bullet with a copper gas check or copper plating is best for INDOOR ranges to keep lead vapors out of the air.

*
Power Pistol, Bullseye, Unique and 2400 are products of Alliant (formerly Hercules) Powders.
Clays, Universal, HP38, HS6 and H4895 are products of Hodgdon Powders.
IMR 3031 and IMR 4895 are products of IMR (formerly DuPont) Powder Company.
No. 2, No. 5, No. 7, No. 9, #2230, and #2460 are products of Accurate Arms Company
WAP (Winchester Action Pistol), WMR, WSF, WSL, 760, 748, 231 and 540 are products of Winchester, Components Div.

References: Accurate Arms Co. 1996 Reloading booklet – – Alliant Powder Co. Reloaders’ Guide (1995) – – Hodgdon’s Basic Reloaders Manual (1996) – – Speer Reloading Manual, #12 – – Winchester Reloading Components Manual, 14th edition – – Lyman Piston & Revolver Reloading Handbook, 2nd edition. – – VihtaVuori Oy Company, reloading booklet (1995) – – Numerous magazine articles on reloading special calibers and personal loads where noted.