reloading 357 sig

[the third pig]

It seems to me that this could be reloaded as any other bottle neck cartridge. One tool I have found very helpful with bottle necks is a Wilson headspace gauge. I have asked them to consider making one. Any of you that want to follow suit may help. Also, does anyone know if a neck sizing die is available? If Wilson could provide us a gauge then we could atleast set the shoulder to match our chamber. In addition, if the spent rounds will rechamber then neck sizing is all that would be necessary in addition to triming. It is suggested that bullets be specified for 357 sig. They are longer on the flat portion and have a shorter cannelure. This is supposed to provide better grip and reduce or prevent setback. Any thoughts?

 

[JimKirk]

Use your barrel as the gauge ...simple as that ....

Get a push through 40 S&W die like the Redding G-Rx or Lee Bulgebuster die ... they size the body ... then use the 357 SIG die to size the neck ... you will need to lube the case slightly ...

You are not going to find a neck sizing die unless you fork out some $$ for a custom made one ... no need for one as regular dies work just fine ...

There are many many 357 SIG loaders and the above method works ... there are quite a few of us here on THR ...

Oh ... yea ... you will need to be careful about the bullets you pick ... no need for a cannelure as a crimp is not really needed other than just a kiss(taper crimp) ... I don't even flare either ... get the neck tension you need and the bullet will be OK unless you put it(same bullet) in and out the gun everyday ...

Welcome to the THR ... don't over think 357 SIG reloading... it is just like a bottle neck rifle cartridge ...

 

[Sunray]

A Wilson headspace gauge just separates you from your money. Cartridges do not have headspace. OAL is measured from the pointy bit to the flat bit too. No ogives.
Like JimKirk says use the barrel as the gauge. Ain't nothing better.

 

[gojones]

I am new to 357 sig also and am waiting on my 357 barrel (Sig P226) and Hornady 147 XTP bullets to arrive. I load 40 cal. already and was going to follow the process mentioned above. I have B-86 powder and was planning on using it to work up a load. Just another way to use one pistol for three calibers (.22lr, 357 sig, and 40 cal.). I think I just wanted to take up the challenge to see how hard it is to load for this caliber.

 

[gojones]

Just to add to my post above, I have ordered some 357 Sig pulled Speer brass from RMR. I read about some issues with small primer flash holes which well see. These cases come primed. I did not want to neck down any 40 cal brass given all the discussion on short cases, etc. Maybe try this later after becoming proficient with this caliber. Any advise on using pulled and primed speer brass?

 

[Fine Figure of a Man]

Don't neck down 40 brass. It is too short and will likely result in little neck tension and bullet setback.
I size and de-prime with a 40 die first the the 357 die. I don't lube but some One Shot would be a good idea.
Case filling powders like Blue Dot or AA9 are more insurance against setback.

 

[ReloaderFred]

Just to add to my post above, I have ordered some 357 Sig pulled Speer brass from RMR. I read about some issues with small primer flash holes which well see. These cases come primed. I did not want to neck down any 40 cal brass given all the discussion on short cases, etc. Maybe try this later after becoming proficient with this caliber. Any advise on using pulled and primed speer brass?

Just remove the decapping pin from your sizing die and resize your primed cases. You'll need to do this for proper neck tension. Loading 357 Sig is really no different than loading most other calibers. I've been loading it since right after it was first introduced to the market.

Hope this helps.

Fred

 

[gojones]

Sounds like I am on the right tract. Thanks for the advice drunkenpoacher and
ReloaderFred. I'll forgo contemplating using 40 cal. brass to neck down later and stick with the 357 Sig brass.

 

[DeadEye9]

As was said don't try to resize .40 brass to Sig especially when new to the cartridge. Using the barrel/chamber from your pistol(s) is the only gauge you will need. For bullets, just about any .355" 9mm projectile works well, and I've tried a ton of them. I tend to stick to the XTP in 124gr and 124 FMJ just because I like the results I get with those in both 9mm and .357 Sig and the prices are good. The 147 XTP is probably the accuracy king of my handloads in .357 though so that's a good choice for you. I've shot 90-147gr from many different manufactures tho and with good loading practices they all work just fine. I will say that when I started I used .356" projectiles to Get proper neck tension but after experience I am able to get any smooth shank common .355 bullet to work just fine. For powder, AA #7 and AA #9 are my go to .357 Sig powders with #9 getting the nod majority of the time. It's the best powder I've found for my Sig loads thus far. Mine get launched from a Glock 32 and 33. Good luck!

 

[Chuck R.]

I just use Dillon 357S dies, use factory 357S brass, make sure my cases are well polished, use a bullet with a long bearing surface (HP or RNFP), and load them over moderately slow burning case filling powder.

LongShot has worked well, Blue DOT, N350 also. Speer 125 FMJ (Designed for 357S) but I've also had very good luck with Berry's 124 HPHB bullets all at about 1350 chronographed.

Mine get launched from a SIG 226 and HK P2000 (CCW gun), both are converted .40s.

Good luck,

Chuck

 

[TfflHndn]

I also use the .40 die for sizing/decapping and the .357Sig die for the neck, and I don't flare the mouth. I have found Montana Gold's .357 sig bullet to be the perfect bullet for me and they don't give me problems with neck tension. I favor AA #9 and Blue Dot for powders. Stay safe and have fun!

 

[Fine Figure of a Man]

I also use the .40 die for sizing/decapping and the .357Sig die for the neck, and I don't flare the mouth. I have found Montana Gold's .357 sig bullet to be the perfect bullet for me and they don't give me problems with neck tension. I favor AA #9 and Blue Dot for powders. Stay safe and have fun!

I don't flare the necks but I do chamfer the inside of the neck. Kind of a pain but you only do it once.

 

[gojones]

If I have a chance, I will get AA#9 and try that. I just have 8# of BE-86 and thought it might be a good match for the 147 grn XTP. Thanks again for all the advice. Lot of experience on this board.

 

[JimKirk]

AA#9 is probably the best powder for someone that is just starting to load 357 SIG ...measures easy, fills the case, good velocity, works with several weight bullets... Just a good all around powder....

 

[atblis]

I've seen some crazy low velocity variations with AA9 in 357 SIG... single digit standard deviations.

 

[the third pig]

I've seen some crazy low velocity variations with AA9 in 357 SIG... single digit standard deviations.

what diameter bullet are 357 sig reloads using? I see both .355 and .357 listed. Any help would be appreciated.

 

[gojones]

The Hornady 147grain 9mm bullets that I loaded were 355 diameter. I would guess the 357 diameter are for 38 special or 357 magnum cases.

 

[Chuck R.]

357 SIG is a .355 diameter, just like 9mm.

You can use 9mm bullets as long as you go with a longer bearing surface to allow for proper neck tension in the short neck, and they have to have a shorter nose profile to maintain OAL. I've used several plated 124 RNFP bullets in my 357 Sigs (HK and SIG) without an issue.

 

[JimKirk]

The BE-86 will work good with a 147 grain bullet ...

Alliant data shows 7.4 grains under a Federal 147 grain as a maximum load ....

Start lower and work your way up ....

I have shot the 147 grain XTP ...but not with BE-86...

 

[Patocazador]

I like Longshot for hot loads in my .357 Sig.

 

[cfullgraf]

I reload some 357 Sig but load more 38/45 Clerke, another bottleneck pistol cartridge. Except for the fact carbide dies are not readily available, if at all, they resize and load just like straight walled handgun cases.

You do have to lube the cases for resizing.

I resize and deprime the case in one step. Size and flare the neck in the second step. I then clean the cases to remove the lubricant. After priming and charging the case, seat the bullet and apply a taper crimp in the third step.

Except for the fact that 357 Sig has some bullet idiosyncrasies, I do not find it any more difficult to load than any other cartridge. Jus follow good reloading techniques.

Good comments already posted.