.357 Sig

[TXCOONDOG]

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_Shadow]

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.

[TXCOONDOG]

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.

[Trapper6L]

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.

[TXCOONDOG]

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.

[Trapper6L]

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.

[Graybeard]

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?

[slayer61]

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.

[sqlbullet]

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.

[Trapper6L]

Have 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.

This 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.

[TXCOONDOG]

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.

[The_Shadow]

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!

[TXCOONDOG]

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 ? 

[The_Shadow]

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...

[ss30378]

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.