SIG 220 10MM Catastrophic Failure

[DM1906]

The pics are the same piece, same incident. The bulged area is the case web area that flowed into the ramp. That is what it looks like when brass flows in a fully supported chamber. If it was a lesser supported chamber, it would have certainly blown out, completely. That load was a ladder workup for a new lot of brass, less than 10 gr. of BD under a 180 gr. bullet.

[DM1906]

The overcharge comes to mind...things like powder bridging can cause an overage or even under charge.  Then there is a possibility of wrong powder being used...like Tightgroup instead of Longshot. 

Normally I would agree. However, the elongated case head and enlarged primer pocket with the blowout indicates inferior brass. Had it not blown out, the case head deformation would have been more exaggerated, such as my pics. My ladder loads were hand weighed, so no chance of powder drop issues, and no doubt it was BD. The same load had 2 KB!s and 3 normal (5 identical loads in the ladder). These were the first step in the workup, 9.6 gr, IIRC.

[4949shooter]

I didn't see the OP specify which load caused this. Or did I miss it?

[DM1906]

I didn't see the OP specify which load caused this. Or did I miss it?

From the original thread at Sigtalk:

"They Were not reloads it was a fresh box of ammo I was trying out. DT hunter 180GR.

The ammo mfg have been the only ones that have actually responded and have said they will write the check (no money yet).


DT has been helpful and responsive."

[4949shooter]

Thanks DM.

[DM1906]

Just a SWAG, but probably this from the description and images: http://10mm-firearms.com/factory-10mm-ammo-pull-downs/double-tap-180gr-nosler-jhp-pull-down/

[4949shooter]

680 foot pounds of energy (advertised).

[The_Shadow]

There was a batch of Double Tap Brass that was bad (poor quality alloy) a while back.  Some was purchased as unloaded cases.
But I still lean toward overcharge being from wrong powder (someone messed up and grabbed the wrong jug). 
There was an incident with Tightgroup powder on GlockTalk that stretched the brass exactly as shown.  Primer was blown out, case head and pocket stretch vertically up and mostly down as the case was supported on the sides by the actual breech face cut. 

Yes mechanized machines can and do make errors such as powder bridging and they usually have a powder check die.  But stuff happens.  This was not the first time Dt had an issue with ammo out of spec and blowing out.

[DM1906]

680 foot pounds of energy (advertised).

680 [magazine accelerating toward your] foot, pounds of energy (not advertised).

[4949shooter]

680 foot pounds of energy (advertised).

680 [magazine accelerating toward your] foot, pounds of energy (not advertised).

Not a good thing! 

[G20Rich]

Doubletap? When a the brass blows like that do you get swelling that can be measured?

Simply, yes. That looks like a brass failure, similar to some I had a few years ago. And, just the same, it was (non-Starline) Double Tap brass. The case dimensions should be near chamber dimensions. DT has been quick to correct (replace with "Double Tap" brass) the failed 10mm brass I've had, but vague with details, only saying the brass was supplied by "other than Starline". Double Tap brass supplied by Starline is "Double Tap" headstamp, while the others, such as "McNett" and "DT" are "other". They wouldn't say who.

If I had to guess who the "other brass" is made by I would go with Armscorp brass, in my experience it is total garbage.

Rich

[DM1906]

Doubletap? When a the brass blows like that do you get swelling that can be measured?

Simply, yes. That looks like a brass failure, similar to some I had a few years ago. And, just the same, it was (non-Starline) Double Tap brass. The case dimensions should be near chamber dimensions. DT has been quick to correct (replace with "Double Tap" brass) the failed 10mm brass I've had, but vague with details, only saying the brass was supplied by "other than Starline". Double Tap brass supplied by Starline is "Double Tap" headstamp, while the others, such as "McNett" and "DT" are "other". They wouldn't say who.

If I had to guess who the "other brass" is made by I would go with Armscorp brass, in my experience it is total garbage.

Rich

Perhaps. However, there are a bunch of cartridge case mfg's, local and abroad, that may have supplied them. Many of them with questionable quality issues, not unlike DT's own quality issues over the last several years. It's to the point now, that I'm close to prohibiting DT ammo on my range. Some purchased as recent as 2 months has had issues. A few squibs (mostly revolver rounds), and radically varied cartridge dimensional issues within the same box, and across the same lot. Countless feeding and ejection issues, as well. This level of quality (un)control is unacceptable, greatly increasing the risk factor. No recent KB!s, but it has been the most inconsistent ammo, by far, of any supplier.

[Dieselman]

If I had to guess who the "other brass" is made by I would go with Armscorp brass, in my experience it is total garbage.

Rich

Could you share with me your experience with Armscorp brass that has caused you to label it as garbage? I ask because I purchased about 500 pieces of new Armscorp component brass when I first got into reloading 10mm last year. It was the only 10mm brass I could find for sale. All my loads have been with with this brass.  While I haven't noted any sort of problem yet, it would be nice to know what to look for based on others experiences. If there is a safety issue with this brass, I would like to be aware of it.

Thanks
Dieselman

[Wolfie]

I have fired at least 1500 Armscor 10mm rounds and saved the brass, all looked just as good as the other stuff I shoot.

[tommac919]

I  also reuse Armscor brass....  They have have shown no problem with my range loads ( BD @ 10.2gr and 180 plated ).  Have reloaded some of them 3x already.