Requesting advice on reloading the 357 Sig cartridge

Greetings! I realize that loading any bottleneck cartridge can be a hassle, especially when it is a pistol cartridge. I will be reloading the 357 Sig for both a Sig P229 and a G32. I am looking for input from reloaders with experience loading the 357 Sig. 


My plan is to deprime, then body size with a gutted 40 S&W carbide die, my cases on my single stage press. Resized cases would then be tumbled. My question then focuses on the following steps: I plan to neck size the cases (carbide 357 Sig die), prime, charge, seat, then roll crimp the cartridges on my Dillon 550. I then plan to do the rotational crimping on my single stage press in order to complete the reloading process. I realize that the process seems long and drawn out, but I am retired and only plan on loading 200-300 cartridges at a time, and this would be faster than loading precision ammo for F class matches! 


Does anyone foresee problems arising from use of the Dillon to load these cartridges? 


As always, thanks in advance for your help! 

Never done it, but was just reading up on this. Sounds like the main issue most have is from how the cartridge head spaces... it’s apparently “kind of” on the mouth and “kind of” on the shoulder. The suggestion I saw was to measure the shoulder setback from a case fired in your gun, and resize to move it a certain amount back. This was supposed to be pretty reliable... for that gun!

Other issue was the amount of neck available to hold the bullet in place is limited. Fix was to use only bullets intended for 357 SIG.

As I said, never done it, but it sounds doable with a certain amount of fuss. I wound up thinking 9x23 was a better idea.

Sounds about right. I tapper crimp my 357SIGs, not roll crimp. I use my RCBS PRO2K to size and de-prime using a carbide 40SW die, followed by the 357SIG die to neck size/re set the shoulder. Then prime and expand the neck. I store these primed cases - currently have 550 in labeled air tight containers ready for loading when needed. I load them using my Dillon 650. Case feeder and RCBS Uniflow PM on station 1, powder check station 2, Hornady bullet feed die station 3, RCBS bullet seater, with different bullet profile stem station 4, Lee factory crimp station 5. I gauge check each cartridge using the EWG Case gauge. Due to the short neck length of the case, you are limited to bullet type. Truncated bullets work better then round nose. So far this works well for me. I have easily produced 400 rounds in an hour without issue, though my normal production run is closer to 200-250. The 357SIG is a fine cartridge and fun to shoot.

I can't comment meaningfully on your proposed method. All my .357 SIG reloading has been done on an RCBS single-stage press with .357 SIG dies. I can however assure you that bullet choice is an issue and you should go with bullets intended for this cartridge specifically. The neck length is a real issue.

As with post #4 I use an RCBS .357 SIG sizing die (with lube) that has the ball type expander like a rifle die. Then I wet tumble which cleans the case and removes the lube. I always check length and trim with any bottle neck case. (i.e. 44-40, 22 TCM, etc) Loading is done on a Lee turret press using the .357 SIG powder thru expander with minimal expansion, then seating in the next station followed by crimping with a Lee collet type factory crimp die in a third station. I found that the neck must be slightly expanded so the bullet doesn’t deform the case neck/shoulder when seating. The collet type crimp is the only way I found that works, at least for me.

Wilson case gauge a must. Hornady Custom dies: 1st size with a carbide 40 S&W. For crimping, the LEE FCD is collet style. Single stage or turret press.

No reason nor need for roll crimp.

Bullets designed for 357 SIG & most with profiles near the XTP's (i.e., most of the various JHPs) work fine. Favorite for range is the BERRYS plated124gr HBFN-TP which can be loaded higher than the typical 1200fps limit for plated bullets.

Cheers!

I'm fairly certain that it's designed to seat on the case mouth and early Federal loadings supposedly had the bullets 'glued' in for retention.

The stated reason for NOT using resized 40 S&W brass for 357 SIG is the fact that the resulting shorter neck area has a negative effect on bullet retention.

A case with a shoulder typically seats on the shoulder. I can see where an incorrectly resized case could cause a potential headspace problem...? Think Wilson case gauge.

Resized 40 S&W brass will individually chamber and fire with the shorter OAL: just not a safe reloading practice as far as possible bullet setback is concerned.

Never heard of "glued" bullets before: is there a reference available?

Cheers!

fordson said:

I use my RCBS PRO2K to size and de-prime using a carbide 40SW die, followed by the 357SIG die to neck size/re set the shoulder.

Click to expand...

I deprime, clean, reprime, then reload or store for later.
My progressive press has 5 stations. I use Lee dies for all 357 Sig operations.
The Lee 357 Sig resizing die is hard enough to not need case lube for shoulder reset only.
Station 1; Body resize with 40S&W carbide sizer die.
Station 2; Size shoulder and neck with 357 Sig full length sizer.
Station 3; Lee powder die to charge, set neck I.D., and very lightly flare case mouth.
Station 4; Seat bullet.
Station 5; Lee collet die for repeatable factory crimp regardless of case length.
ETA: This setup has produced flawless ammo for 7 years now.
Also ETA: I too have successfully used the Berry's plated. I believe that as long as velocities are held to below 1400FPS there will be no problems.

mikerjf said:

Sounds like the main issue most have is from how the cartridge head spaces... it’s apparently “kind of” on the mouth and “kind of” on the shoulder.

Other issue was the amount of neck available to hold the bullet in place is limited. Fix was to use only bullets intended for 357 SIG.

Click to expand...

When I first developed my 357 Sig load procedures I ran a few 40S&W cases through out of curiosity. Every one gauged the same as a 357 case EXCEPT every neck was a few thousandths too short for a proper collet crimp. Each one passed the plunk test on all 3 of my 357 Sigs.
All of my reloads seem to headspace on the shoulder, regardless of neck length.

lrrifleman said:

Greetings! I realize that loading any bottleneck cartridge can be a hassle, especially when it is a pistol cartridge. I will be reloading the 357 Sig for both a Sig P229 and a G32. I am looking for input from reloaders with experience loading the 357 Sig. 

As always, thanks in advance for your help! 

Click to expand...

I have been shooting and hand loading the 357 SIG cartridge since the mid 90s. Over those years I have loaded 10s of thousands of rounds of 357 SIG on a progressive press.

Why so much ammunition?

Unfortunately some one moved my tripod, but here are 30 rounds of 357 SIG on target in just over 2 seconds

[ame]https://www.youtube.com/watch?v=b6wMRqxaxiI[/ame]

Yes the novelty of full auto fire does wear off, but when I go shooting with my associates this is one of the most requested firearms I am asked to bring along and I also used to shoot various sub-gun matches. It takes lots of ammunition to practice for these

The die stations on my Lee Loadmaster are exactly the same as Tex1001 describes above.
Projectile shape is critical in the 357 SIG. Most projectiles originally designed for the 9MM have an ogive that is still sloping right where we need neck tension in this cartridge. This is why various manufacturers have designated certain designs as being for 357 SIG

As STORMINORMAN mentions, the Hornady XTP has a great profile for the 357 SIG cartridge, so does the less expensive Hornady HAP. You will very quickly pick up which profiles work well with the 357 SIG and which do not

No matter what is published in SAAMI or various gun rags, this cartridge head spaces on the shoulder like almost all bottle neck cartridges. Make that case body just a bit too long and the breach will never close, make the case body too short and it still fires just fine

Personally, I have never loaded the 357 SIG cartridge with plated bullets (except subsonic). Since the MP5 has an 8.3" barrel all of my hand loads exceed 1200 FPS. Some of the loads I use lighter projectiles in actuallt top 1700 FPS from the long barrel. Obviously sub sonic ammunition for use with the suppressor travels below 1086 FPS

Now, this cartridge is well suited to PC coated bullets. Most of the various powder coatings have proven to hold together very well at the higher velocities.

The Lee Factory Collet Crimp die is a blessing for this cartridge. It makes many projectiles that would have been a marginal choice, very viable in this short necked case

The first and only time I shot the .357 SIG was with a couple of NASA engineers. I thought it was a great cartridge, not as loud or snappy as legend claims. All their ammo was reformed .40 brass. They said they didn't have any problems nor did I.

Just an FYI, Rocky Mountain Reloading has their .355 bullets broken down into a category that you can select profiles designed for .357 SIG. Their 124 and 115 truncated cone flat points look very promising.

Since I plan on loading 9 and .357 SIG, I'll likely just order these and use them for both. .357 Sig (.355") | RMR Bullets

To get a proper dimension-ed .357 SIG case from a reformed case, you have to use a 10mm to get a long enough neck.

There seems to be some differing opinions on forming usable cases from 40S&W brass. Maybe we need a poll on this.

I've never attempted reforming 40 S&W into 357 Sig. I just use the Starline brass purchased a while ago. It would be quite a squeeze to neck down 40, so I wonder about neck wall thickness. I sure wouldn't want to find myself trying to ream or turn the necks. Or should I say "necks" since there isn't much of one.

Another curiosity . . . . I snagged some once-fired 357 Sig brass. T the shoulders were stretched out more than I'd expect. I don't know if they were fired in a loose gun or what. They do have the tell-tale Glock primer appearance if that's of any significance. If I go ahead and use them, they'd experience a significant shoulder setback when I size them. I'm not thinking that's a good thing at all.

glider1 said:

There seems to be some differing opinions on forming usable cases from 40S&W brass. Maybe we need a poll on this.

Click to expand...

I'll be the 1st to vote: NO WAY.

Cheers!

P.S. The reason: one bullet pushed back far enough while chambering and... KABOOM!. Not worth the price of once fired 357 SIG brass.

glider1 said:

There seems to be some differing opinions on forming usable cases from 40S&W brass. Maybe we need a poll on this.

Click to expand...

usable? likely, but not to full spec, thus iffy at best.

colt_saa said:

url]https://www.youtube.com/watch?v=b6wMRqxaxiI[/url]
The die stations on my Lee Loadmaster are exactly the same as Tex1001 describes above.

Click to expand...

I thought that I was the only idiot that still used a LEE load master.

Tex1001 said:

I thought that I was the only idiot that still used a LEE load master.

Click to expand...

The Load Master is GREAT, what a step up from the Pro 1000

I have two Load Masters. One gets left setup with large primers and the other small primers

John Lee and his Father Richard before him have been wonderful resources for projects I was building and manufacturing loading equipment that did not exist before our talks.

I mourned Richard Lee's passing a couple of years ago.

Richard Lee's vision of the Lee Loader opened up affordable hand loading to tens of thousands, perhaps hundreds of thousands of folks that originally thought it was a rich man's hobby

So many great innovations.

The Collet Crimp die is something that should in the hands of so many pistol shooters.

I use the RCBS Turret Press for my 5-die 357 SIG reloading... Leaves me an empty station (when set up thusly) for any miscelanious work on another caliber. The Hornady locking die rings keep any adjustments at a bare minimum, but it does take a while to remove those 5 dies. Probably why I still do the majority of my reloading on single stage presses?

Sure wish there was room to thread it for a Hornady Lock-n-Load bushing, though...?

Cheers!