357sig Loading

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HookedOnTheOutdoors

New member
Hi Everyone

I have been reloading rifle and shotgun ammo for a little over 30 years, mostly 308, 30-30 and 12 guage. In the past year I decided to purchase a Glock 23 and now have a Lone Wolf 4" 357 SIG barrel for it. My experience in reloading handgun ammo is limited, only about 1-1/2 years of 357 magnum and 9mm.

The reason I am posting here is that I really like the SIG round and want to get very good with it, beginning with reloading. I've been reading a lot about bullet set back and am a little concerned.

I have big supply of Unique powder and of Hornady XTP 124s and want to use them. I realize this isn't the most popular powder for this round, but considering my inventory and my wife's patience on my new investments running thin, I really should use what I have.

What is the best way to prepare the cases to minimize the chances of a set back?

Are there any tips that you can share to minimize the chances of a set back after the rounds are reloaded? In other words, a reliable way to test them before I load them in my gun?

Thanks for any info you share.
 
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Brian Pfleuger

Moderator Emeritus
Unique is actually a pretty good powder for the Sig, because it is one of several that can have compressed loads, which helps reduce setback issues.

Hornady's max load for the 124gr XTP is 7.9gr Unique, OAL 1.140.

The easiest way to load for the Sig is to get a 10mm carbide sizing die and use that in the first step. This eliminates the need to lube.

Step 2 is the normal 357Sig die, which will not require lube if used after the 10mm die because it is sizing only the neck.

Using a minimum flare in step 3 also helps setback. Many times, you can get away with no crimp at all.

In step 4, when applying the crimp or, more correctly, removing the flare, make sure to use minimum force to bring the case mouth back into spec. Excessive crimp will bulge the neck away from the bullet and REDUCE neck tension, increasing setback issues.
 
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Dave P

New member
Setback was a problem before. But if you use the Lee Factory Crimp die, it won't be again. Very simple. Not case prep required.

Peetza - I just recently added that 10mm carbide die to the process. Works quite well, and the other Lee dies get much less scratched up!
 
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Brian Pfleuger

Moderator Emeritus
I use the FCD on 357sig too but you have to be careful. I messed around with a bunch of different crimp amounts and found there's a very fine line that suddenly and dramatically makes setback worse, if you cross it. It's not all that radical a crimp, either.

I quit using it because when you also use the 10mm die, you now have 5 steps and my Classic turret only has 4 stations. I now rely on a mild crimp applied during seating and compressed powder charges. I don't have any troubles.

A good test is to press a finished round against the edge of our workbench and see how much force it takes to change the length, and how much.
 
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jepp2

New member
I full size using a .40 S&W carbide die. I had it on hand and it works just fine. Then I size using the 357 Sig die without lube.

I get less setback (around 0.001 to 0.002") with my handloads than the factory ammo has. And that is with my die set up to headspace off the shoulder, not the case mouth. So the case neck is very short.

But, I make sure I use the right bullet (critical) and don't expand the neck at all. I seat the bullets with care and don't crimp afterwards. Works for me.

To help you get started, I am including a link to the first of 4 articles on loading the .357 Sig I found extremely helpful. Links to the other articles can be found in the first article.

http://www.realguns.com/Commentary/comar65.htm

Once you get your process defined, I don't find the Sig to any more of a challenge to load for than the 22 Jet, 32-20 or any other cartridge that involves a little more definition than just cycling the press.

Her is what my loaded ammo looks like

 
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HookedOnTheOutdoors

New member
357sig loading

Thank you for all of the info. I reloaded a few this morning. I found that unless I flared the mouth of the case slightly (1-2000th) I ended up crushing the case when I tried to seat the bullet.

I ended up using my 9mm expanding die to do this, being extremely careful not to do anything other than a very slight flare at the mouth of the case. I now have some rounds loaded, and am going to chrono them and see where I am at. I loaded a few with 7.2, 7.6 and 7.9 of Unique.

Another part of my test is going to be small pistol mag primers. Yes, I know its not advised, but that's all I can get my hands on. I plan to chono them also and look for signs of overpressure. I was able to do this with my 9mm loads and as it turned out I didn't need to adjust the amount of powder. I was just looking at the case and primer then. I bough a chrony yesterday and am going to use it for these tests. Hopefully I wont have to change my user name to "one handed Joe" :eek:
 
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Brian Pfleuger

Moderator Emeritus
HookedOnTheOutdoors said:
Another part of my test is going to be small pistol mag primers. Yes, I know its not advised, but that's all I can get my hands on. I plan to chono them also and look for signs of overpressure. I was able to do this with my 9mm loads and as it turned out I didn't need to adjust the amount of powder. I was just looking at the case and primer then. I bough a chrony yesterday and am going to use it for these tests. Hopefully I wont have to change my user name to "one handed Joe"
Click to expand...

I use CCI small rifle primers in 357sig. At least in the case of CCI, they are identical (literally, the same exact product) as small pistol magnum primers. I worked up to the listed max load of 800x under 125gr FMJ and have continued to use it but it is... energetic. ;)

Caution is warranted.
 
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HookedOnTheOutdoors

New member
357 sig reloading

Ok, I managed to screw up my first session with my new chrony (lost track of which rounds were used on which string.)

Anyways, using the exact data out of the Hornady 9th edition manual, I seem to be running about 100fps faster than what the book says i should.

The differences I can see are:

The book uses a 3.82" barrel, I have a 4.02 barrel.

My C.O.l is 1.35. the book states 1.40.

Will any of these explain the difference?

I was being as precise as possible measuring my powder.:confused:
 
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HookedOnTheOutdoors

New member
357 SIG reloading

Probably 2-3 feet. Should I be standing a specific distance? If so, how far? I really didnt see much in the directions about that. Rifles needed to be about 10 feet because of muzzle blast, but it said that pistol could be closer.

Has anyone else used small pistol magnum primers instead of small pistol primers?

I can only see about 50 fps difference and no signs of overpressure.

Is there some other reason I shouldnt do this?

I tried the following with 7.2, 7.6 and 7.9 grains of Unique with a Hornady 124 gr XTP:

Winchester Small Pistol (WSP) (this is what the book calls for)

Winchester Small Pistol Magnum (WSPM)

CCI Small Pistol Magnum #550

Federal Small Pistol Magnum

Like I said I screwed up my data and going to have to run the test again, but no signs of over pressure and some of the rounds were breaking 1400fps.
 
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Brian Pfleuger

Moderator Emeritus
At 3 feet, I'm surprised the muzzle blast didn't tip the chrony over. :D

10-15 feet is good.

See my post above about magnum primers.
 
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HookedOnTheOutdoors

New member
357 sig reloading

Well, it was mounted on a pretty sturdy tripod ;)

I need to reload some more shells now. I figure on doing another test this week, probably Wednesday evening.

I didn't notice your comments on the mag primers before. I may try to get some small rifle primers locally and try them also.

Is there a way to find out how many feet the test barrel was from the chrony when Hornady developed their recipe? Or is 10' just a common distance everyone uses?

Thanks for all of the replies.
 
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Brian Pfleuger

Moderator Emeritus
Is there a way to find out how many feet the test barrel was from the chrony when Hornady developed their recipe? Or is 10' just a common distance everyone uses?
Click to expand...

Actually, if there's any "standard" it's probably 15 feet. I'm pretty sure that what Hornady used to use but nowadays they use radar or high-speed cameras. I saw their tech talking about it in a video awhile back.

The thing that matters is consistent, accurate readings. The speed lost from the muzzle to 15 or even 30 feet is going to be smaller than the random variations anyway.

Last weekend when I tested my 800x loads with the small rifle primers, I started at about 5 feet just to see if I could get a reading... it's easier not to shoot you chrony at 5 feet too... the first shot rocked the whole setup, almost tipped it over. "Hm. Too close says I.":D
 
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HookedOnTheOutdoors

New member
357 sig reloading

Are these indetions in the primers normal for a SIG?

They were loaded with a Winchester small pistol primer. the top 2 had 7.6 gr of Unique. The bottom 2 had 7.9

WSP loads.jpg
 
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HookedOnTheOutdoors

New member
357 sig reloading

Awesome. Out of the 28 that I shot all but maybe 3 or 4 looked like that. The rest looked as though the primer bulged out some. Kinda looked like a dome. The firing pin actually pierced the cup on one of them.

I brought home a lighted magnifier today and mounted on my bench. It really helps with detail. Eyes aren't what they once were :)
 
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RB98SS

New member
All great info in regards to loading this cartridge. The only thing I'd add is many people use AA#9 for 357sig as it fills the case to the point where it would be impossible to suffer setback. It's a good performer too.

Sorry if someone already mentioned it....
 
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HookedOnTheOutdoors

New member
357 sig reloading

I didn't notice the domed ones until I had already punched them out of the cases. I believe they were all Winchester Small Pistol Magnums and that there would have been 3 with 7.6 gr and 1 with 7.9. I only loaded one max load with each brand of mag primer. I wasn't sure how it was going to go.

One of the things that I have learned during this project is that your data is only as good as the way its prepared, tested, and recorded. From now on I am keeping each recipe bagged separately until I am satisfied that I have gotten all the info I can from them.

My guess is that those Winchester rounds were overpressure? Its interesting because I think they turned in the lower velocity average between them and the CCI / Federal mag primers.

I've seen the AA#9 suggestions several times. My problem is that I ended up with 11 LBS of Unique thanks to Natchez Shooters Supply refusing to cancel a 1 day old order. Anyways, between the expense of the Glock 23, the drop in barrel, a few hundred dollars of powder and a chrony I have managed to where my wife's understanding down to a point that I really don't want to test it further. The Unique will work, I just have to be careful how I go about it I guess. That's why I'm on here. There seems to be a lot of experienced members that are willing to lend a hand.

I will post more accurate data after my new round of tests.
 
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