357 Sig revisited

ligonierbill

New member
I started loading this round a couple years ago after reading yet another caliber debate, specifically, "Does it really match .357 mag/125 from a 4" revolver?" In my case, it was a Glock 23 with an aftermarket barrel vs. a 4" GP-100. At the time, the result was, "Not quite." The Sig trailed the revolver by about 100 fps with both commercial and mine. Still, I like the round and this week picked up a Sig P226 in, of course, 357 Sig.

I want to do some more workups and see what I can get out of it. Maybe I'll try some 147s this time. So, what are you folks working with? I've used mostly AA#9 and a little Power Pistol.

And please, no caliber wars. With the exception of .25 ACP, I load and shoot "all of the above".
 
I don't load this round, but for what it's worth, with a 124 grain XTP, QuickLOAD thinks both Power Pistol and Accurate No.7 will give you about 50 fps more from a 4" barrel than No.9 will.
 
I load 357 SIG and it is indeed an equal to the FACTORY 125 357 MAG.

Of course us re-loaders aren't stuck with factory. I'd say it's similar to how 308 win reloads are faster than 30-06 factory loads but the 30-06 can be hand loaded faster yet of course.

I have had great success with the 125g Speer TMJ that is made just for 357 SIG, as well as the 124g Rainier Plated HP. I use and prefer the Hodgdon LONGSHOT powder as it fills the case and performs well for me.

800x is also a great powder in the 357 SIG if you can deal with the metering issues. 1400 fps is easily reached with either powder in the 125g and 1300 fps with 147g Speer Gold Dots and TMJ were nice shooters and very accurate.

The 147 will be about 50 fps slower with LONGSHOT but is far easier to meter and works better for me on my Dillon 550b.

I picked up 2000 once fired brass for about $120 ( mostly speer, some folks have issues with a smaller than normal primer hole although I didnt. )

Happy shooting.
 
I picked up a G33 >10 years ago and I still like it a lot. Even tried for a CZ 75 conversion from 40 with a Firedragon barrel, they quit offering them during the 10 day waiting period we have in CA. Dangit!

In 2008 I had to buy everything for handloading pistol calibers again as my state passed a law banning mailorder ammo sales. Went from handloading high power match ammo for accuracy to loading 9mm for freedom. No beuno!

At any rate, Power Pistol won the competition for what to buy (Unique is so 1980's for me) and my cheap chrony says I get 1310 fp for 125 gr GDHP. Since I get 1360 with my DoubleTap carry ammo for the same bullet, I figure they're braver than I am or using a blend. It's loud and shouty like Power Pistol should be, but I dunno what it is.

I picked up a factory G27 barrel and a 9mm conversion barrel from LWD. Wow, is the G26 a great shooting little pistol! And wow, do I NOT dig 40 S&W, so slow back on target compared to 357 SIG.

I recently bought a G22 because I couldn't find a G31 (CA = not much choice) and of course bought an LWD 357 SIG and 9mm barrel. Again, what a great, nice shooting pistol the G17 is! As much as I like my Argie High Power clone (sans disconnect), I can see how the Glocks took over the world. I've been shooting/carrying a G21 since 1993, I thought "soft" was an artifact of low pressure 45 ACP. Nope.

I'll have to chrono my G31 simile, I'd sure like to get near 1500 with some copper bullets I assembled for the ranch. No way I can get the performance of my 4" or 6" 357 Mags with H110 behind them, but 11 rds of 357 SIG is NOT to be trifled with!
 
357sig data

DISCLAIMER! Do not use this load data, it is for a reference only. Some loads were used in a pistol that has been modified to accept loads loaded to 1.280" long. Any attempt to reduce cartridge overall length may result in damage to the gun, shooter, or others nearby!!!

With that out of the way, longshot, blue dot, 800x and power pistol will give good numbers. Underwood uses longshot in their loads as verified in pulldowns and comparable workups.

My gun is a longslide g20 running a 6" barrel with the throat opened up so I can load rounds 357mag diameter bullets (up to .359) to full 10mm length. So most of my loads will be impossible to run in a stock gun but it can give you an idea of what is possible.

From the 6" barrel loaded long oal:

Speer once fired brass with cci550 primers
125gr zero jhp .357 dia @ 1.240", 12.0g blue dot = 1602fps avg
158gr berrys plated hp .357 dia @ 1.250" 9.5gr blue dot = 1371fps avg
180gr MBC cast "pugnose" @ 1.250" 9.0 blue dot = 1278fps avg

125gr xtreme plated .358 dia @ 1.260", 11.0g longshot = 1736fps avg

No loads above gave out of the norm case head expansion, primers were flat on the 125g longshot load. The 180 grain MBC "pugnose" was the powder coated version.

Standard OAL loads in a 4.5" kkm barrel g23:

Also loaded with xtp's for the 357mag.

New Starline brass, CCI SP primers
125gr XTP, 10.5gr 800x @ 1.140": 1,618 AVG
140gr XTP, 9.5gr 800x @ 1.140": 1,456 AVG
158gr XTP, 9.0gr 800x @ 1.140": 1,388 AVG

Point of reference:
Underwood 125gr load uses 10.0g of longshot so start well shy of that should you choose to replicate.

Realguns has some good power pistol data as well.

Hope that give's you some idea of what can be possible with the sig. As always start low and work up.
 
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