Help diagnosing failed case

[MGW]

This seemed like the best place to post this. If not mods let me know please.

Here's the case in question.









This is one of our hand loads. Dad does the majority of the set up, testing, and loading. Press is a Dillon 550. His experience is very high and powder weights are checked and rechecked before, during, and after a loading session.

It looks like a simple failed case. I'm willing to buy that if that what it is. The pistol it was fired out of was a Sig P320 FS. This pistol has fired less than 400 rounds since a trip to Sig. It was sent back because of poor accuracy.

According to Sig they recrowned the barrel, checked all specs, test fired, and tested for accuracy at 15 yards. They also adjusted the trigger bar. They returned a test target that showed good accuracy at 15 yards.

The reason I'm posting this up is because this is the third failed case in approximately 500 rounds with this pistol. One happened before it went back to Sig. It was some older reman ammo. I can't verify what the manufacture was.

The second failed case happened after it was returned by Sig in the first 50 rounds of test firing. It was the same brand of ammo from a different lot. All of that ammo was disposed. I didn't get an opportunity to pull any of it part and check powder. This time the extractor was blown out of the pistol. It also cracked a large grip frame right above the cutout where the serial number shows on the firing mechanism. Dad was able to located the extractor and reinstall it. He inspected the pistol and didn't find any other damage to the pistol.

The third cased failed Saturday when I was shooting a match with the pistol. When the round went off it felt like a squib. I got a face full of unburnt powder and a lot of smoke. After clearing the pistol I inspected the barrel to verify clear and checked the rest of the pistol. It just happens to be the last round of the stage when it failed. I was allowed to test fire the pistol. It worked fine the rest of the day. I out maybe two hundred rounds through it after that.

I've been shooting a long time. I've never had a failed case. Three in the same pistol just seems like to much of a coincidence. I can see any sign of over pressure around the primer. The pistol seems to be fine. Sig said the pistol is fine. All three case had a blow out near the base. This is the only case that also had a crack near the neck. The other two rounds were brass not nickel.

Should I be worried or is this just and string of bad luck?

[Lon]

What exactly are you asking? Obviously it failed, but what's the history of the case? New, reload, brand?

Looks like a 9mm major load that got shot out of a Glock factory barrel. Pressure blew the bottom of the case toward the rear (which is unsupported in a glock) out the bottom.

[MGW]

What exactly are you asking? Obviously it failed, but what's the history of the case? New, reload, brand?

Looks like a 9mm major load that got shot out of a Glock factory barrel. Pressure blew the bottom of the case toward the rear (which is unsupported in a glock) out the bottom.

I hit post on accident. Explanation is included now.

[Lon]

To me it seems to be an ammo issue and not a pistol issue. I'd buy 1k of good new factory ammo and shoot it. If there's no problems I would not worry about it. I've seen quite a few cases give out over the years. Most of them have been from shady ammo companies or brass that's been reloaded a bunch of times.

Even experienced loaders make mistakes. Seen it way too many times over the years.

[HCM]

To me it seems to be an ammo issue and not a pistol issue. I'd buy 1k of good new factory ammo and shoot it. If there's no problems I would not worry about it. I've seen quite a few cases give out over the years. Most of them have been from shady ammo companies or brass that's been reloaded a bunch of times.

Even experienced loaders make mistakes. Seen it way too many times over the years.

This ^^^^

[Wayne Dobbs]

The cracked mouth is usually indicative of work hardened, worn out brass. How many times has it been loaded....or does anybody even know?

The failed case head and web is an over-pressure load and/or an under-supported case head. I'd lean toward the over pressure situation. What is the load, specifically? Is it a book load or a POOMA one (POOMA = Pulled Out of My Ass)?

Finally, as previously suggested, get quality factory ammo and shoot it for a 1000 rounds. I'll bet you have no troubles, which will then isolate your issues to this reloaded ammo.

[MGW]

The cracked mouth is usually indicative of work hardened, worn out brass. How many times has it been loaded....or does anybody even know?

The failed case head and web is an over-pressure load and/or an under-supported case head. I'd lean toward the over pressure situation. What is the load, specifically? Is it a book load or a POOMA one (POOMA = Pulled Out of My Ass)?

Finally, as previously suggested, get quality factory ammo and shoot it for a 1000 rounds. I'll bet you have no troubles, which will then isolate your issues to this reloaded ammo.

Don't know the number of times on the case pictured. It's Sig brass and I would have to make an assumption on number of times loaded. More than once obviously.

If I remember correctly this round was 124 X-treme round nose over 4.3 of 231. That's near the top of the load in newer manuals.

It just seemed strange to have that many failures with a new pistol in a short amount of time. We'll shoot factory new rounds for awhile and see what happens.

Thanks for the input all.

[deputyG23]

The cracked mouth is usually indicative of work hardened, worn out brass. How many times has it been loaded....or does anybody even know?

The failed case head and web is an over-pressure load and/or an under-supported case head. I'd lean toward the over pressure situation. What is the load, specifically? Is it a book load or a POOMA one (POOMA = Pulled Out of My Ass)?

Finally, as previously suggested, get quality factory ammo and shoot it for a 1000 rounds. I'll bet you have no troubles, which will then isolate your issues to this reloaded ammo.

Ditto to the above. In most cases, reloaded ammo adds too many variables to determine issues regarding a particular firearm.
My son and I were shooting some old 9mm commercial reloads from my work's early 9mm days when admin insisted on buying this stuff for quals. Sure enough, he had a case blow out. He yelled and dropped the G19 in the dirt. No injury to him or the gun.
I had a case blow out on me last week in my P228 when I was trying to figure out FTF issues with it. Felt the burning powder on my hand and cleared the pistol. The case had split lengthwise down the center.
The earlier advice regarding buying a case of quality factory ammo for diagnosing potential gun issues is spot on.

[Wayne Dobbs]

Don't know the number of times on the case pictured. It's Sig brass and I would have to make an assumption on number of times loaded. More than once obviously.

If I remember correctly this round was 124 X-treme round nose over 4.3 of 231. That's near the top of the load in newer manuals.

It just seemed strange to have that many failures with a new pistol in a short amount of time. We'll shoot factory new rounds for awhile and see what happens.

Thanks for the input all.

There's nothing wrong with that load at all, assuming that is what the load contained. Now, if a bullet pushed back in the case during functioning into the chamber, that would dramatically raise pressures and possibly cause this incident. The bottom line is, we don't know what we don't know on this one. Another reason to stay with factory ammo as much as possible.

[LSP972]

Is it a book load or a POOMA one (POOMA = Pulled Out of My Ass)?

I am SO stealing that one.

BTW, you owe me... the latent print girls, two rooms away, came in here to see what I was LMAO about; and then lipped up because they didn't get it.

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