The Down Range Forum
Member Section => Tactical Rifle & Carbine => Topic started by: 2HOW on January 27, 2010, 09:45:29 AM
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http://thegunzone.com/m1akb.html
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This has been circulating around for quite some time now. I believe it was attributed to a surplus run of Indian ammo. I know this article says it was German ammo, but I think IIRC it was later determined to be Indian. There were a lot of other issues with this ammunition, but this was the worst. Bill T.
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In following the links in the article and reading Fulton Armory's analysis of the rifle, including microscopic examination of the rifle components, they determined the failure was caused by faulty manufacturing of the barrel, in particular, improper cooling during the process.
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so was it the surplus ammo or the barrel?
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so was it the surplus ammo or the barrel?
According to the links I followed, the report from Fulton Armor stated it was the barrel.
Here is the link to the entire Fulton report http://thegunzone.com/m1akb/762r.html
And here are the pertinent statements:
The problem with this barrel2 is that the ferrite grains are quite large and interconnected through the pearlite grains. Because ferrite has so little carbon in it, it has roughly the strength of iron. It is the weaker constituent of the steel. Because the grains are large, interconnected and many sit on the surface of the bore, they are prime sites for cracks to form.
This steel was most likely held at too high a temperature for too long. This allowed the austenite grains to grow too large and resulted in the large ferrite grains.
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It must have been brittle like cast iron. It sounds like it wasn't very far out of spec either. That's what's really scary.
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It must have been brittle like cast iron. It sounds like it wasn't very far out of spec either. That's what's really scary.
Yes...I tried a bit to find in the links where the barrel originated, but it was stated that the barrel was totally unmarked and that the owner was the only one that would know and that he had made his statement earlier. It then said that this info was as lost as the burial site of Jimmy Hoffa.
I tried a bit to track the story, but didn't find anything further.
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It's possible. There was another M-1A blowup that was due to improperly loaded Indian ammo. Sako had a rifle let go a few years back due to a batch of bad barrel steel, so it can happen.
http://www.hs.fi/english/article/1101978285825
http://www.thegunzone.com/rifles-kb.html
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From the way things are looking, its starting to look like the ammo.
I'm sure the sup par barrel( which is of unknown make) played some roll in this.
I'm wondering if by chance the ammo is some of that "spiked" ammo, you know the stuff they use leave/ dump in vietnam, so when they VC would use it, thier guns would blow up.
I've seen lots of rifles that have blown up when some one loads a "pistol powder" in a rifle. they look nothing like this, They tent to take a chunk out of the side of the rifle.
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From the way things are looking, its starting to look like the ammo.
I'm sure the sup par barrel( which is of unknown make) played some roll in this.
I'm wondering if by chance the ammo is some of that "spiked" ammo, you know the stuff they use leave/ dump in vietnam, so when they VC would use it, thier guns would blow up.
I've seen lots of rifles that have blown up when some one loads a "pistol powder" in a rifle. they look nothing like this, They tent to take a chunk out of the side of the rifle.
Check out the link to the Fulton Armory examination. Their microscopic inspection of the barrel showed many cracks in the barrel. The barrel was old and used with about 3500 round through it, but their inspection indicates that the failure was caused by the many old cracks that some of which just gave way with this round.
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It also said the cracks were old. 3500 rounds is nothing, for a semi auto rilfe.
It was also clear that they do not know if the bad ammo cuased the failure or if it would have failed other wise.
Also look at the pics of the primer, when guns blow up there is less persure in the chamber, not more( obstucted barrel is a diffrent story) ITs clear that there was a over persure in the chamber.
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Again, an excerpt from the Fulton report
An examination of the primer face did not show any signs of excessive flattening or deformation. There were no indications of excessive pressure in the case that would have contributed to the cause of failure.