10mm-Auto

Miscellaneous Firearms => Handguns => Topic started by: TXCOONDOG on December 08 2019 06:46:39 AM MST

Title: .357 Sig
Post by: TXCOONDOG on December 08 2019 06:46:39 AM MST
Interesting that SIG calls it a 357 when everything I read states it uses a .355"  (9mm) bullet.

How accurate is the round ?

Anyone convert there 40 to the Sig .357 ?

Your favorite powders, etc ?

Likes, dislikes and other thoughts ?

Title: Re: .357 Sig
Post by: The_Shadow on December 08 2019 07:02:21 AM MST
Well that's because SIG was trying to duplicate the 357 Magnum velocities with the 357SIG cartridges.  Yes the bullets are 0.355" presa, however I have load some 0.357" bullet for mine with slight increases of pressure.
The rounds are as accurate as the firearm they are fired from.
My use of the 357 Sig cartridges are from the G-29 using a LWD conversion barrel.  Although I like the 9x25Dillon conversion as well.
I use Blue Dot, 800X, Longshot, AA#9, Power Pistol mostly
The thing to understand is they are a bottle neck cartridge and they require almost perfect headspacing (0.000" Flush to no less than 0.002" below flush) with the chamber hood of the barrel. 
Other things to be aware of is neck tension with the bullet.  Poor bullet fit can lead to bullet setback issues during feeding...Best dies have been the Dillon dies with dual carbide sizing sections.
Title: Re: .357 Sig
Post by: TXCOONDOG on December 08 2019 08:58:53 AM MST
I love the 10mm and 357 mag and cast a lot of bullets for both.

I like the fact that the 9x25 Dillion uses the 10mm as the parent case.

I do like odd calibers and mess with forming my own brass, etc for different Wildcat rifles.

Just looking for something different to tinker with in a pistol.
Title: Re: .357 Sig
Post by: Trapper6L on December 08 2019 10:09:36 AM MST
The biggest issue I find with the 357 Sig is finding a bullet that's worth a crap that will work in the thing. Most of the bullets are too long. It requires a short, blunt shaped bullet or you run into issues with it not fitting in the mag. I find it a pain to load for. My brother is the one that has it. His is a Sig by brand and is a 40 SW with the 357 Sig barrel as a set. Accuracy is decent enough at 25 yds. I'm loading Unique powder in his. Brass is not a problem yet as some of the LEOs still use the round around here. Frankly, I get more 357 Sig brass than bro will ever shoot. They bring it in 5 gallon buckets to give you an idea.
Title: Re: .357 Sig
Post by: TXCOONDOG on December 08 2019 10:37:24 AM MST
The Shadow now has my focus on the 9X25 Dillion.

I see Bar-Sto produces a barrel for the Glock 40 MOS. Will I need to fit the barrel ? Also, any other manufactures that I should consider for the 9x25 Dillion.

I didn't find anyone producing a conversion barrel for the 4.5" XDm in 10mm.
Title: Re: .357 Sig
Post by: Trapper6L on December 08 2019 12:56:49 PM MST
If you're looking for a wildcat to play with, try the 38/45acp, also known as the 38 Clerke. It's the 45 acp case necked to 38 caliber. You end up with a 1911 that shoots 357 bullets at about the same velocity as a 357 mag. To do the chambering all you need is the reamer and a 38 Super barrel. Mine is built on a 1911 Gov't model with  a lot of Gold Cup mods. Shoots incredibly accurate but I lose a lot of cases due to splits at the shoulder. A lot of annealing required to form cases. Load data is available online. My understanding is that it's popular in Australia.
Title: Re: .357 Sig
Post by: Graybeard on December 08 2019 02:42:49 PM MST
Quote from: Trapper6L on December 08 2019 12:56:49 PM MST
If you're looking for a wildcat to play with, try the 38/45acp, also known as the 38 Clerke. It's the 45 acp case necked to 38 caliber. You end up with a 1911 that shoots 357 bullets at about the same velocity as a 357 mag. To do the chambering all you need is the reamer and a 38 Super barrel. Mine is built on a 1911 Gov't model with  a lot of Gold Cup mods. Shoots incredibly accurate but I lose a lot of cases due to splits at the shoulder. A lot of annealing required to form cases. Load data is available online. My understanding is that it's popular in Australia.

Have you thought about forming.40 Super brass for this?
Title: Re: .357 Sig
Post by: slayer61 on December 10 2019 07:47:35 AM MST
Quote from: TXCOONDOG on December 08 2019 10:37:24 AM MST
The Shadow now has my focus on the 9X25 Dillion.

I see Bar-Sto produces a barrel for the Glock 40 MOS. Will I need to fit the barrel ? Also, any other manufactures that I should consider for the 9x25 Dillion.

I didn't find anyone producing a conversion barrel for the 4.5" XDm in 10mm.

I got the Bar-Sto barrel for my G20 last year. I don't believe any one else is still making them. The barrel will require some slight fitting. It will come with instructions on the job. Bar-Sto also offers the option of fitting it for you, if you like.

The 9X25 is a great deal of fun to shoot. Enjoy.

Edit to add: I got to thinking about the 9X25 & forgot this was a 357 Sig post.

I also reload 357 Sig & have used several powders with good results. Unique, CFE and BE-86 most recently.
Title: Re: .357 Sig
Post by: sqlbullet on December 10 2019 08:15:14 AM MST
Watch e-bay and you may find some 9X25 barrels for sale.  I lucked into a ported 6" barrel for my G20 and a factory length barrel for my G29 on eBay at the same prices the Lone Wolff used to have them.  They were both new in box unfired from all I could tell.

I like the idea of the 357 sig.  I am a fan of velocity and SD, and bottle-neck calibers tend to increase velocity and SD at the sacrifice of the raw projectile diameter.  I have a P229 with both a 40 and 357 barrel, and put a 357 Sig barrel for my G27 on the santa list this year.

Projectile options are limited to work with the gun.  This is an area where the 38 Super exceeds the 357 Sig, but 38 Super barrel options are even more limited than 357 Sig unless you have a 1911.
Title: Re: .357 Sig
Post by: Trapper6L on December 11 2019 10:00:36 PM MST
QuoteHave you thought about forming.40 Super brass for this?

No, mostly because I wasn't even aware of a 40 Super. Guess I'll have to see about looking at the sizing differences and what will be required to make it work. Almost looks like the 38/45 is the same thing just eyeballing the case with pics of the 40 Super. Shoulder placement looks to be REAL close if not exactly the same. Looks like all I would need is to neck it down which would save a butload of work and cost as 45 cases, even annealed, don't like to make the transition. I lose about 20% as I recall in forming the brass. Been awhile since I fooled with it. Thanks for the heads up.

QuoteThis is an area where the 38 Super exceeds the 357 Sig
I have the 38 Super in a Colt Special Combat that is sweet. It's a luxury to load for compared to the 357 Sig. The Colt shoots almost any bullet you can put in it too. Weighing the differences, the 357 Sig is a boat anchor.
Title: Re: .357 Sig
Post by: TXCOONDOG on December 12 2019 04:25:38 PM MST
Reached out to KKM and Dan put me on a waiting list for a 7.25" threaded barrel chamber in 9X25 Dillion.

Anywhere from 60-90 days and they call to see if you are still interested, if so, 2-3 weeks produce them.

Thanks to all.
Title: Re: .357 Sig
Post by: The_Shadow on December 12 2019 04:51:26 PM MST
TXCOONDOG, I reached out to them about making one of their barrels for the G-20 / G-40 6.02" chambered for 357Sig, but they said no back then.  I may need to reach out again!
Title: Re: .357 Sig
Post by: TXCOONDOG on December 13 2019 07:13:38 AM MST
Quote from: The_Shadow on December 12 2019 04:51:26 PM MST
TXCOONDOG, I reached out to them about making one of their barrels for the G-20 / G-40 6.02" chambered for 357Sig, but they said no back then.  I may need to reach out again!

Did anyone ever offer a 6" conversion barrel for the .357 Sig ? 
Title: Re: .357 Sig
Post by: The_Shadow on December 13 2019 08:04:16 AM MST
At one time I think LWD di offer a 6.02" version for the G-20 chambered for 357 Sig.  I am still looking for one of these to add to my barrel collection.
I think that they offered a 9" 9x25 at one time as well...
Title: Re: .357 Sig
Post by: ss30378 on December 23 2019 11:19:54 AM MST
This is right up my alley, I've had all these...  I just recently got my 7.25" 9x25 Barrel from kkm as well.

So in total I now have a 357 sig in both the 6" g24 glock and 5" 1911 platforms, a kkm 7.25" 9x25 Dillon barreled g40, and a 38/45 improved similar to the 38 casull in a 6" custom g40 I opened the breechface on to run the 45 diameter case.  I used to have 6" g20/40 LW 357 sig and 9x25 barrels I still have data from as well.

Besides the 90xtp and 65g lehigh 9mm bullets, I run .357/.358 diameter bullets up to 180g in them.

Performance wise they are in that order 357<9x25<38 casull.

Top numbers

90g xtp
sig: 2150fps in 6"
dillon: 2303fps in 7.25"
38 casull: 2418fps in 6"

125xtp (.357 dia)
Sig:1750fps in 5"
Dillon: 1912fps in 7.25"
38 Casull: 2014fps in 6"

158xtp (.357 dia)
Sig: 1600fps in 5"
Dillon: 1642fps in 6"
38 casull: 1745fps in 6"

180 cast wfn (.358 dia)
Sig: 1460fps in 5"
Dillon: not tested yet
38 casull: 1616fps


The sig in a 10mm sized gun loading to 10mm length gives up little to the Dillon with bullets over 125g.  As you see above I've stoked my 5" 1911 with 158s to 1600fps while in my old 6" 9x25 barrel I ran a 1642fps max load for the same bullet in a 1" longer barrel.  The 7.25" barrel will probably run a bit faster but its a much bigger gun. 

With light bullets the long barrels make a notable difference.  125s in the 5" 1911 top out at around 1750fps, in the 7.25" 9x25 Im over 1900fps.  The 38 casull has broke 2000fps with a 125xtp in its 6" barrel.

Most of my top numbers have come from slow powders like aa9, 2400, and 300mp.



Title: Re: .357 Sig
Post by: 4given on December 24 2019 03:12:45 PM MST
I have a Glock 31 (.357 Sig) and love it! An accurate pistol and cartridge IMHO.

I find it easy to reload and find bullets for.  I use  Hornady .355 / 9mm 124 Grain XTP over Power Pistol for serious loads and X-treme plated .355 / 9mm 124 Grain over AA#5 for range fodder.

I have had no problem with head spacing.  While they are supposed to head space on the case mouth, I suspect they usually head space on the shoulder. I lightly lube them with spray lube then just run them through a Lee steel sizing die and that's it.   I then tumble them with SS pins, soap hot water and lemishine. Once dry I load them up and crimp them with a Lee factory crimp die to prevent bullet set back.  Easy peasy.

Title: Re: .357 Sig
Post by: Overkill338 on February 05 2020 12:44:16 PM MST
Quote from: TXCOONDOG on December 08 2019 06:46:39 AM MST
Interesting that SIG calls it a 357 when everything I read states it uses a .355"  (9mm) bullet.

How accurate is the round ?

Anyone convert there 40 to the Sig .357 ?

Your favorite powders, etc ?

Likes, dislikes and other thoughts ?
The .300 Magnums all use .308" bullets. The .240 Weatherby uses .243" bullets. The .378 Weatherby uses .375" bullets. The .404 Jeffery uses .423" bullets. The .460 Weatherby uses .458 bullets. The .380 auto uses .355" bullets. .38 Special uses .357 bullets.

My point? Its stupid to try to make something out of the .357 SIG using .355" bullets.
Title: Re: .357 Sig
Post by: JJJackson on February 28 2020 01:02:40 PM MST
Quote from: TXCOONDOG on December 08 2019 06:46:39 AM MST
...How accurate is the round ?

Anyone convert there 40 to the Sig .357 ?

Your favorite powders, etc ?

Likes, dislikes and other thoughts ?
The .357 Sig is a very accurate, hard hitting & flat-shooting round ... along with the 10mm & 7.62x25, it's right at the top of my favorite caliber heap.

All my 357s are actual .357s, save for an HK VP40 & Steyer L40-A1 which were purchased for the sole purpose of converting them to .357 Sig ... which I did, thanks to Rim Country Manufacturing & their excellent barrels. All it takes to turn a .40 S&W into a .357 Sig is a barrel & possibly, depending on how you & your pistol perform, a different front sight.

My favorite powders are AA#9 & 800X, the latter which, though it meters like a bag of Doritos, is one of the best kept .357 Sig secrets ... it affords amazing results @ diminished pressure levels. I go the two-step, lube-free route when it comes to sizing - i.e., I first run cases through a Redding 10mm carbide sizing die & then through a conventional Redding .357 Sig sizing die. Having experimented with a number of different bullets, I now load exclusively with Montana Gold FMJ & JHP 125gr .357 &/or RMR (9mm/.357 Sig) JHP 124gr Multi Purpose bullets ... both are excellent performers & have the perfect ogive for .357 brass. Yea, I quit pulling my hair out @ the bench once I started using those bullets!

Title: Re: .357 Sig
Post by: cwlongshot on March 11 2020 06:50:26 PM MDT
Late to this party. I was also late to the lil 357 SIG. but I tried to make up for it with a barrel for every 40 I had and two new pistols in 357 Sig!! ;)

I bought a G24 so I could buy a 6" KKM 357 Sig barrel!!

Crazy velocities have been achieved and almost across the board accuracy increases over same gun in 40.

CW
Title: Re: .357 Sig
Post by: Rooster41 on March 13 2020 12:34:42 PM MDT
I was a big fan of the 357 Sig back in the day, hence the screen name. I got away from it a long time ago. Ammo was too expensive for me (at the time) and I wasn't into reloading yet. I have not reloaded any 357 Sig. A few years ago a buddy of my dads moved out of state and had a bunch of ammo he couldn't take with. I ended up with 400 rounds of 357 Sig. I recently found a Glock 32 factory barrel for $50. Good thing I have a Glock 23 to put it in. I forgot how much I liked the 357 Sig. Nice and accurate. I haven't decided if I will load for it yet or if I will buy a box or two of ammo every now and then. Hell, I may even sell the barrel when I shoot up these 400 rounds. I don't know yet.
Title: Re: .357 Sig
Post by: cphills on March 28 2020 03:14:37 PM MDT
I have a LWD 357 sig bbl for my G20. So far, limited experience hand loading this caliber but had no trouble with XTPs. I'll be rotating this project into focus on dialing in the recipe over the next couple of months.
Title: Re: .357 Sig
Post by: The_Shadow on March 31 2020 05:02:07 PM MDT
cphills, what length 357SIG LWD barrels did you get???  I have wanted to add a 6.02" for my G-20 and have begged LWD to make them again...I did manage to obtain a factory length recently.
Title: Re: .357 Sig
Post by: cphills on September 28 2020 11:57:26 AM MDT
Hi Shadow, Sorry for my very slow reply. My LW G20 357 bbl is factory length.
Title: Re: .357 Sig
Post by: gnappi on February 03 2021 08:42:04 PM MST
I have .357 sigs in a number of platforms since the cartridge first came out... 1911, Sig, and Beretta. Reloading is easier than some make it out to be, and I've shot 158 JHP's (resized in my Star sizer) also. Feed has been exceptional with the exception of 125 grain LRN's they jam in my Sigs, not my 1911 or Beretta.

The reason I never got a 9x25 Dillon is I can get more .40 brass than 10mm to re-form. Even with the short neck I've had no issues with setback if crimped.