reloading the 357 SIG

[Boolseye]

I'm starting this thread as a catch-all for the basics on this cartridge.
I learned everything I needed here at the forum, but there is a shortage of info.

The primary challenge in reloading for .357 SIG is getting through the neck tension issues and finding good boolits. The bottleneck only has about 3/16" that grip on the boolit, so a boolit with enough of a top driving band, and a short enough nose for the mags is a necessity. Examples of boolits that I have used thus far: Lee 356-120 TC (standard groove), Lee 358-158 RF, Accurate 35-147S. Many folks rely on a full case of slow powder to act as a stop for the boolit, and to ensure that set-back doesn't happen. I prefer to also give each round a good crimp.

Boolits that have been known to work are:
Lee 358-125 RF
Lee TL356-95RF
Lee 358-105 SWC
NOE 357-135RF (Ranch Dog)
Accurate 35-125S (357 SIG nose length)
Accurate 35-147S (" ")

Jax:
Hornady XTP HP 124 and 147

Traditional long-nose 9mm boolits such as NOE's 358-135 RF/128 HP) will likely not function well.
too little upper driving band, too long a nose.

Lets hear from ya 357sig shooters!

[lightload]

Lee makes a factory crimp (collet)die for .357 Sig. Others have pointed out that a 40 S&W carbide die works for sizing the case section below the neck.

[awhite]

Any suggestions for 125 bullet loads? I have Unique, Bullseye and Power Pistol. I'm loading for an H&K VP 40 with a .357 Sig barrel which slugs at .357.
Thank you.

[dansedgli]

Accurate 168z and mihec 135 grain work well too.

[Moonie]

I'm using the Lee 125 FP, size with 40 S&W then 357Sig crimping with the collet FCD. Working perfectly with around 7gr of Unique or around 9gr of AA#7.

[Beef15]

Any suggestions for 125 bullet loads? I have Unique, Bullseye and Power Pistol. I'm loading for an H&K VP 40 with a .357 Sig barrel which slugs at .357.
Thank you.

I would use the Power Pistol. I had good results with the Lee 120TC and that powder, don't remember the charge.

What will likely be a challenge for you is expanding the neck for and/or seating a fat enough cast bullet without collapsing the shoulder, I have for the time abandoned cast in my 357Sig due to losing 1/10 or more. Perhaps someone can offer a solution?

[Boolseye]

I have not had any shoulder collapse issues-as I recall I just used a Lyman m-die and gave the mouth a flare. I drop my powder charge then seat as normal with a strong crimp, done as a separate stage. I may have used the Lee universal expander to flare, I can't recall. Expansion of that little neck is important or you will shave lead and possibly crush a shoulder. Just going from memory, it's been a while.

[dragon813gt]

What will likely be a challenge for you is expanding the neck for and/or seating a fat enough cast bullet without collapsing the shoulder, I have for the time abandoned cast in my 357Sig due to losing 1/10 or more. Perhaps someone can offer a solution?
Use a proper expander. I've never experienced any shoulder collapse issues. As stated neck tension is usually the biggest issue. W/ the Lee short bottle neck collet style FCD that's no longer an issue either.

[Boolseye]

Update: The NOE 358-150 ELKO design works well in this cartridge. It's a great choice for a heavy. I believe I went with 6.5 gr. 800x and got about 1000fps.
This load was very low and could be kicked up if the shooter needed more power.

[dkf]

How are you getting the Elco to seat at 1.140" COAL with any neck tension.

[bstone5]

The Accurate 35-120G also woks well in the 357 SIG. I size to 357 after powder coating then a home made gas check is installed. Have shot many in a 375 SIG. Use the Lee crimp die for a small crimp so as not to damage the powder coat material on the cast bullet.
Use the same bullet in 38 Special with 3 grains of Trail Boss for the ladies and grand children to shoot in revolvers.

[Boolseye]

How are you getting the Elco to seat at 1.140" COAL with any neck tension.
I don't recall the exact OAL, I think I did 1.145". It worked great in my M&P.
Neck tension was fine too. I do use a strong taper crimp on .357 SIG, using the Lee fcd.