.357 Sig Reloading Blues

[Squaregrouper]

I thnk the neck expander ball on a rifle case is lower than the neck size ring. It sizes the OD on the way down (w/ the ball inside the case already), and it sizes the neck ID w/ the ball on the way up.

Ohh SG, You could press them into your lyman case gauge w/ an Arbor press (or a simple vise.)

Atblis has a good idea too - do they chamber when you drop the slide on them? If its close enough, the slide will drive them home to size. Warning, if you try this and don't want to fire it, they might not come out easily. So don't test this part at home

This is a very good idea. I'm going to try it on a few.

 

[atblis]

That's not what I was suggesting. My point was that the case gauge is likely on the tight size, but the rounds might chamber just fine in the gun. IMO, the best way to load 357 Sig is to use the slide and barrel as a gauge and to set the shoulder bump such that the rounds headspace off the shoulder. You can check this by bumping util the the barrel with a case in the chamber will lock into the slide, and you can see a sliver of daylight between the breach face and the case head. Feeler gauges can be used if you want precision. I just do it by sight.

 

[Squaregrouper]

That's not what I was suggesting. My point was that the case gauge is likely on the tight size, but the rounds might chamber just fine in the gun. IMO, the best way to load 357 Sig is to use the slide and barrel as a gauge and to set the shoulder bump such that the rounds headspace off the shoulder. You can check this by bumping util the the barrel with a case in the chamber will lock into the slide, and you can see a sliver of daylight between the breach face and the case head. Feeler gauges can be used if you want precision. I just do it by sight.

The Lyman gauge is far tighter than the factory barrel, which I no longer have. I am now using a 5.5" ported Bar Sto barrel, which isn't much looser than the case gauge. Of the 122 gauge failed cases, about 3/4 also failed the KKM plunk test. If I still had the factory G31 barrel I would just send them.

 

[atblis]

Looking at your pictures, it looks like the case has buckled right below bullet

.

 

[atblis]

This one looks like a grove

 

[Squaregrouper]

This one looks like a grove

View attachment 452149

I am a reasonably experienced reloader, but not an expert by any means. The pictures don't fully represent what I am looking at in person.
In the quoted picture above, visualize brass shot from a loose chamber then FL resized, but the brass was "short seated" by about a millimeter. This was due to the die being loose in the toolhead. This, in turn, prevented proper shoulder bump and the shoulder angle isn't correct on the faulty rounds.
Enlarge the picture in post #38 and you might be able to see what is obvious in person. One fits comfortably in the Lyman gauge; the other is the exact cartridge shown in the failed Lyman gauge picture.

 

[85MikeTPI]

You can’t resize 357sig with a projectile installed, it won’t enter the neck sizing section of the die.

Pull all the incorrect ones and resize with the 357sig die and decapping pin removed

 

[atblis]

I think you got other problems as well. That round on the left side of the akro been looks to have a messed up neck as well.

 

[Squaregrouper]

I just tried the @smdub method of using the Lyman gauge with a vise, and it worked, but I had to coerce the cartridge back out from the bullet side. I then tried on the press and the OAL went from ~1.140 to ~1.120. I tried twice and it happened both times. Those rounds are now in the trash. I am going to proceed with the smdub method for the remaining rounds, using calipers to check every OAL.
.
ETA- the failed tolerances were close enough I am sure they would have chambered in a factory Glock barrel without the smdub steps.

 

[Squaregrouper]

I think you got other problems as well. That round on the left side of the akro been looks to have a messed up neck as well.

The deceptive pictures are why I was hesitant to post them. What MDS is seeing on their computers is different than what I'm seeing in person.
The @smdub method confirmed my suspicions- the shoulder was slightly under bumped.