Catastrophic failure in my SA15.7 - A happy ending from Colt Canada

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Benito said:
This is a very odd failure indeed. Overpressure ammo usually messes up bolts, carriers and the upper in places other that the rear lug. Also, the shooter usually feels/hears somthing noticeably unusual when firing ammo that is high pressure enough to mess up their gun.
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Did you not read the OPs posts?
 
I have question, let's say CC does NOT want to cover this accident. Would MFS have the reputation of covering a blown up AR? I've seen quite a few AR explosions online and it's always "talked to the manufacturer of the rifle". Seldom do I see people contact the maker of the ammunition.
 
EDX2308 said:
I have question, let's say CC does NOT want to cover this accident. Would MFS have the reputation of covering a blown up AR? I've seen quite a few AR explosions online and it's always "talked to the manufacturer of the rifle". Seldom do I see people contact the maker of the ammunition.
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No case failure..... Nothing exploded here, the rear lug sheared off the upper. Strangest failure I have seen on an AR15 ever.
 
COLT CANADA said:
We are happy the shooter was unhurt.

The user reported an unusually loud bang and hard recoil. The case was difficult to extract. The case was steel not brass and did not burst as a standard brass case would have. The barrel and the bolt remained intact and there was no evidence to suggest a barrel obstruction.

The resulting high pressure caused a very energetic opening. The bumper on the rear of the buffer was mushroomed and deformed and the key recoiled hard enough to contact the lower receiver at the top of the extension hole.

All the evidence points to an overcharged cartridge. Similar damage was recreated in the lab supporting this. The upper receiver forging was examined by a metallurgist and there were no flaws or defects. There is no anodizing in the cracked metal to indicate it was cracked prior to delivery. We are satisfied that there was absolutely nothing wrong with this rifle at the time the incident occurred.

The fact that the user was uninjured despite continuing to fire after an abnormal ammunition incident would seem to show that the materials were more than up to the task. The manual does say that if you hear an abnormal sound you should stop firing.

Without having the actual case or having the evidence preserved properly, and with the tendency toward forum members making all the worst assumptions despite lacking any qualifications, we are not able to release a report laying cause on any particular ammunition manufacturer.

We chose to replace the components as a customer satisfaction gesture, despite a complete lack of liability on our part, and not because the rifle was made from pot metal and we were trying to hide a defect. It seems it will be much harder in the future to help out folks since we will also have to defend what we thought was going above and beyond for a customer to the experts on the internet.

Other folks might come to a different conclusion given the above incident. Perhaps they might note that Colt Canada is a world class manufacturer with an excellent reputation for quality and safety and that this is consistent with that. Perhaps they might notice that the consumer was able to contact the manufacture directly, someone was able to listen to their concerns. The equipment was able to be returned directly to the factory without an export license and the manufacturer went to the trouble of setting aside other work to conduct a thorough investigation of an relatively minor incident that in all likely hood had nothing to do with our manufacturing processes.

Some folks love to point out that the Diemaco rifles are expensive. Some folks might think that you get what you pay for.
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How about rewording this to, "some forum members".
 
Familygunnutz said:
I'm just gonna put this out there, this is an american colt, I don't see any rear pin damage, do you? if US colt's rear can take that much force and stay intact.....what do you think?
6920boltcarriersplitf-tfb-tm.jpg

6920boltfacesplit_2-tfb-tm.jpg

6920upperblownapart.jpg
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Totally different failure, different cause. In other words, irrelevant.
 
I think it is just bad luck and a bad round from MFS, very rare it's like winning the power ball lottery only you are not winning. Perhaps the MFS bad round is due to the rush on manufacturing a few years back and the C8 just happened to have a weak spot in the rear or crack in the metal and all that energy culminated there. No big deal.

Perhaps it's the SA BCG ....just kidding.
 
COLT CANADA said:
We are happy the shooter was unhurt.

The user reported an unusually loud bang and hard recoil. The case was difficult to extract. The case was steel not brass and did not burst as a standard brass case would have. The barrel and the bolt remained intact and there was no evidence to suggest a barrel obstruction.

The resulting high pressure caused a very energetic opening. The bumper on the rear of the buffer was mushroomed and deformed and the key recoiled hard enough to contact the lower receiver at the top of the extension hole.

All the evidence points to an overcharged cartridge. Similar damage was recreated in the lab supporting this. The upper receiver forging was examined by a metallurgist and there were no flaws or defects. There is no anodizing in the cracked metal to indicate it was cracked prior to delivery. We are satisfied that there was absolutely nothing wrong with this rifle at the time the incident occurred.The fact that the user was uninjured despite continuing to fire after an abnormal ammunition incident would seem to show that the materials were more than up to the task. The manual does say that if you hear an abnormal sound you should stop firing.

Without having the actual case or having the evidence preserved properly, and with the tendency toward forum members making all the worst assumptions despite lacking any qualifications, we are not able to release a report laying cause on any particular ammunition manufacturer. We chose to replace the components as a customer satisfaction gesture, despite a complete lack of liability on our part, and not because the rifle was made from pot metal and we were trying to hide a defect. It seems it will be much harder in the future to help out folks since we will also have to defend what we thought was going above and beyond for a customer to the experts on the internet.

Other folks might come to a different conclusion given the above incident. Perhaps they might note that Colt Canada is a world class manufacturer with an excellent reputation for quality and safety and that this is consistent with that. Perhaps they might notice that the consumer was able to contact the manufacture directly, someone was able to listen to their concerns. The equipment was able to be returned directly to the factory without an export license and the manufacturer went to the trouble of setting aside other work to conduct a thorough investigation of an relatively minor incident that in all likely hood had nothing to do with our manufacturing processes.

Some folks love to point out that the Diemaco rifles are expensive. Some folks might think that you get what you pay for.
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andrew3081 said:
Without any proof, CC can not just say bad MFS ammo caused this failure.
No one is interested in the real reason why this failure happened?
It could be ammo or it could be the rifle.
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Please note that Colt Canada said nothing whatsoever about any particular brand of ammunition. In addition, Colt Canada pointed out that in the absence of the the cases and ammunition, a definitive report cannot be made available.
 
OK,

Have a look at the .gif below.

Look at the pink "block" of the gas carrier key. Consider if the bolt was pushed to the rear with enough force to actually damage (bulge/balloon) the rear of the buffer that the bolt would have been pushed further to the rear than it is designed to...aso you see here in this picture.

Note. The charging handle should NOT be reciporcating with the bolt as it moves.

But, if the bolt carrier was driven back past where it should go, where is that pink piece (gas carrier key) going to go and what is it going to do? It's going to maybe get pushed back in a way that may cause an upward push by the gas carrier/key on the charging handle, pushing the upper receiver UP as the bolt exceeds it's normal rearward travel.

What's that UPward push going to do? Probably cause a failure exactly as we've seen in the OP's photo, and rip the rear takedown pin out.

I could be wrong, and I don't have an AR in front of me to look at the exact mechanics in person (I will tomorrow believe me!) but this *SEEMS* like a possible cause/effect relationship that could have caused the damage.

Well done to Colt Canada for standing behind your product and fixing a problem that wasn't even yours!

NS


71033.GIF
 
As much as this is not a normal blowout for an AR15, colt have 100,s of not 1000,s of documented blowout like this. Over 50 + years. So I'm sure its happen before.
As for not picking on the ammo, it happens with all the other major brands of ammo as well
 
Dont laugh but some ex spec forces look like that now... Doesn't mean they were not more badass than any of us could ever wish to be at one point in their life
 
NavyShooter said:
OK,

Have a look at the .gif below.

Look at the pink "block" of the gas carrier key. Consider if the bolt was pushed to the rear with enough force to actually damage (bulge/balloon) the rear of the buffer that the bolt would have been pushed further to the rear than it is designed to...aso you see here in this picture.

Note. The charging handle should NOT be reciporcating with the bolt as it moves.

But, if the bolt carrier was driven back past where it should go, where is that pink piece (gas carrier key) going to go and what is it going to do? It's going to maybe get pushed back in a way that may cause an upward push by the gas carrier/key on the charging handle, pushing the upper receiver UP as the bolt exceeds it's normal rearward travel.

What's that UPward push going to do? Probably cause a failure exactly as we've seen in the OP's photo, and rip the rear takedown pin out.

I could be wrong, and I don't have an AR in front of me to look at the exact mechanics in person (I will tomorrow believe me!) but this *SEEMS* like a possible cause/effect relationship that could have caused the damage.

Well done to Colt Canada for standing behind your product and fixing a problem that wasn't even yours!

NS


71033.GIF
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Not sure about this, seems like if the if the pink piece were to exceed the normal range there would be a massive dent above the buffer tube (which doesn't seem to be the case in op pic)

Also the animation is correct, the first frame has the hammer down, so the animation is showing a manual cycle.
 
tiriaq said:
Please note that Colt Canada said nothing whatsoever about any particular brand of ammunition. In addition, Colt Canada pointed out that in the absence of the the cases and ammunition, a definitive report cannot be made available.
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I should have said Colt Canada indirectly said the bad MFS ammo caused the failure. CC have pointed out the cause of failure is 100% ammo related which is hard to proof without the empty ammo shell cases that were shot from the rifle. If CC blamed the ammo for the failure and the OP stated he was shooting MFS ammo when the failure happen, then CC indirectly pointed out that MFS caused the failure.
 
Someone pull an MFS and check out if you can overcharge it or how much it can be. I seem to recall that the cases are darn full anyway. How many grains are in there anyway? If we're going to look at the ammo, let's see if it can and how much it can be overcharged. I too find it hard to conceive that much larger rounds don't sheer the rear normally but this does. You can put a .338 Lapua upper on any AR lower so....
 
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