357 SIG

[Cecil S.]

Gentleman , I have purchased a Glock 33 in 357sig. I could not resist the bottleneck cartridge to reload. I have done my homework on this but wish to reach out to the experts for advice. Anyone reload for this?

 

[joshb]

I'll be watching this one. I was going to by one but heard of a whole bunch of "reloading nightmares" with it. I'd like to hear some updated info.

 

[biggen0_8]

I set my dies up to bump the shoulder about .003". I use 800X which I know flows like wet oatmeal, but I trickle every charge and use a compressed load, which helps eliminate bullet setback problems. Hope that's of some help.

 

[Cecil S.]

I'll be watching this one. I was going to by one but heard of a whole bunch of "reloading nightmares" with it. I'd like to hear some updated info.

joshb , I had the same concerns but after reading as much info as I could find I thought this was a challenge that I wanted to try.

 

[Cecil S.]

biggen0_8 , How did you measure the Datum? I was playing with my Forester Datum Dial. Not much to work with!

 

[jepp2]

Most important to pick the correct bullet. If you don't, the taper will reduce neck tension. As mentioned, I set up to headspace off the shoulder. Accurate No. 9 is a popular powder and provides bullet support. I use Montana Gold 357 Sig bullets. http://montanagoldbullet.com/index.php/357sig-125gr-jhp-194.html

I find the Redding 357 Sig Competition bullet seating die to be a big help.

I found this series helpful:
https://www.realguns.com/Commentary/comar25.htm
https://www.realguns.com/archives/001.htm
https://www.realguns.com/Commentary/comar65.htm
https://www.realguns.com/Commentary/comar66.htm
https://www.realguns.com/Commentary/comar66.htm
And when you are done, they will look just like this:

 

[Cecil S.]

Montana Gold makes rounds just for 357 sig so these will help set tension and clip to chamber issues.

 

[Cecil S.]

jepp2 , Nice. Yes Montana Gold is the way to go. Do you run your once fired through a 40SW die before the 357sig die? I am starting with Unique but will use AA9 once I get the hang of it.

 

[biggen0_8]

biggen0_8 , How did you measure the Datum? I was playing with my Forester Datum Dial. Not much to work with!

I believe I've been using a resized 40 S@W case as a bump gage. I don't remember for sure if that is the right or not, been several months since I reloaded any. I use a 124gr. XTP bullet.

 

[Ringostar]

Yes, use a 40 s&w carbide die to size the body first. Then your 357 sig die for the neck. I don't have to lube cases with this method. Most have been doing it this way for years. I also have the Lee collet crimp die.

 

[Dans40X]

OP,New Gun,
IF your combat tupperware(glock) has an un-supported chamber....tread lightly!

The 357 SIG case IS NOT a necked 40 Short & Weak case, as the 357 SIG case headspaces on the case MOUTH like any other straight walled rimless pistol case.

Sizing/headspacing off the shoulder will introduce issues for your striker fired tupperware.

I cast/size/lube .358" 125gr at 18Bhn radius flat nose projectiles to .356" diameter in my 357 SIG/38 Super(P226/P228/P229/P220 in conventional non polygonal German rifling & have been for the last 25+ years w/o issues.

 

[Sniper338]

Ive loaded it for years and years for my glock. I use 40sw cases mainly. clean em up, then run them through the carbide 357 sig sizer and decapper. A power punch decapper is cheap and a great decapper to install in your die. can get them from midway, fixes the hard to deprime glovk fired brass issue.

Get bullets for 357sig, regular 9mm dont work exactly right. It aint hard. Dont let people fool you with jibberish. Just set your dies up, make sure the brass cycles right, then load one, make sure it cycles right... once its all set up right your golden

 

[McFred]

I've been loading it since 2004. The SAAMI sheet says it headspaces on the case mouth, but likely as not it's either headspacing on the shoulder or in the case of a Glock-like pistol it's just as likely to headspace on the extractor groove if chamber dimensions are a bit too generous (I wager $10 you can shoot 357sig through a Glock 22 .40s&w though I'm not recommending it). Your specific pistol may be different than everyone else's; it's on you to do the due diligence. I just set my RCBS die to headspace on the shoulder and bump the shoulder back ~.003"

As mentioned, don't use 9mm parabellum projectiles. Truncated cone type bullets like the Hornady XTP or HAPs work well. Sierra recently released a SIG-specific V-Crown projectile that works well. I'm still running through a pile of FMJ 125gr PMC projectiles whose profile look surprising similar to the Montana projectiles linked above. I've used jacketed projectiles up to 158gr designed for .357 Magnum without incident too. I have also used 158gr .358" cast RNFPBB projectiles for light plinkers. With heavy projectiles, the short OAL pushes a lot of the bullet heal into the case, reducing effective capacity raising pressures though, so tread lightly.

With the short case neck, neck tension is more critical, but if you have a consistent lot of brass, properly prepared, then you can quantify any setback by measuring the length of a dummy cartridge and racking it to battery again and again while measuring to see if the OAL changes. With projectile hitting the feed ramp I have noticed some setback, but it has never been excessive and it has been predictable in my case.

Feel free to hotrod the case, but make sure the case head is fully supported, Bubba might have tried to increase feeding reliability with a die grinder to the ramp if you're buying 2nd hand. To that end you can use .40 S&W brass, but it will not hold the same pressures as the SIG headstamped brass and the already short case necks will be even shorter risking bullet setback and again raising pressures.

I have used AA7 and AA9 as well as Unique, I've found that AA9 is dirtier than the faster powders, but it just may be the lot I have. Unique is very clean with low muzzle flash.

Lastly, I've never needed a crimp. If you do crimp, don't over do it or again you may compromise the neck tension. Be observant, test and work up your loads and you should be fine. It's no different than loading anything else in my opinion; certainly not a 'nightmare.'