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Posted: 4/21/2011 10:16:31 AM EDT
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My brother had a little mishap with his Doublestar yesterday as you can see in the pics. Not sure if it was a hot load or what. But anyhow here's the damage. I also want to use this thread to brag on Nick and the guys at Doublestar. My brother is sending the gun back to them. They are repairing the gun and paying him back for the shipping costs. There's not alot of companies out there these days that back their products like this. Stand up guys at Doublestar!!
http://i812.photobucket.com/albums/zz50/Wolverinefan44/152.jpg http://i812.photobucket.com/albums/zz50/Wolverinefan44/154.jpg http://i812.photobucket.com/albums/zz50/Wolverinefan44/157.jpg http://i812.photobucket.com/albums/zz50/Wolverinefan44/164.jpg http://i812.photobucket.com/albums/zz50/Wolverinefan44/148.jpg |
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Quoted: Hot load wasn't the problem, I think. Possibly poor headspacing, or a very out of battery discharge. The fact that the lugs look unharmed makes me wonder. Bad headspacing I could understand (although not sure if it would do this), but out of battery discharging is not possible. The firing pin doesn't even reach outside of the bolt prior to the bolt being fully seated on the round. The only way this is possible if if the retaining pin is badly bent, broken, or not present. I'd link Molon's "BS Busters" thread but I can't find it anymore. May have been removed or archived. |
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Quoted: The retaining pin prevents rearward movement of the firing pin, not forwards. The flange on the firing pin interfacing with the bolt carrier prevents OOB firing.Quoted: Hot load wasn't the problem, I think. Possibly poor headspacing, or a very out of battery discharge. The fact that the lugs look unharmed makes me wonder. Bad headspacing I could understand (although not sure if it would do this), but out of battery discharging is not possible. The firing pin doesn't even reach outside of the bolt prior to the bolt being fully seated on the round. The only way this is possible if if the retaining pin is badly bent, broken, or not present. I'd link Molon's "BS Busters" thread but I can't find it anymore. May have been removed or archived. ETA: I have the spelling ability of a drunk monkey. |
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It's a good thing to publicly thank your vendor for good product support. Applause.
BUT... There's a lot more you could/should be saying about this incident than is in your post, unless there is no intent to learn something here that is. 1. Ammo 2. History - eg, 300th round of a 10 mag dump... 3. State - eg, round supposedly in battery, ready to fire, pulled the trigger and kaboom... or kaboom while bolt was closing... 4. etc, etc... It's hard to tell from the pictures, but it doesn't look like the bolt was closed when the kaboom occurred. |
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Quoted:
It's a good thing to publicly thank your vendor for good product support. Applause. BUT... There's a lot more you could/should be saying about this incident than is in your post, unless there is no intent to learn something here that is. 1. Ammo 2. History - eg, 300th round of a 10 round mag dump... 3. State - eg, round supposedly in battery, ready to fire, pulled the trigger and kaboom... or kaboom while bolt was closing... 4. etc, etc... It's hard to tell from the pictures, but it doesn't look like the bolt was closed when the kaboom occurred. Sorry for the lack of info sir. Factory ammo here's a link to the same kind. http://www.afte.org/forum/smf1/index.php?topic=4840.0. Bought it in bulk several years ago. Gun has had approx 600 rounds threw it total. Took it out yesterday. Put in a magazine, pulled back the charging handle let it go, pulled the triiger and boom. As far as the lower goes it looks fine I can't see any visible damage. And as far as the case goes it is it is still wedged into the barrel. You can actually see the headstamp in picture two. Also in picture two is three pieces of metal beside the gun. From left to right is a piece of the bolt carrier, the primer, and a piece of brass from the round. I am not near as knowledgeable as you guys on here. I hope that was a little bit better explanation. |
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Why is there loose gunpowder all over the towel that these pictures were taken on?
Why wasn't this posted by "your brother"? Is he 9 years old? How can you peel the bottom section of the bolt carrier clean off without destroying your entire gas system also? Yes, I see the rear gas ring out of its seat. Why does it look like this mal-treated weapon has never been lubricated in its life? I'd like to see a lot more credibility in this thread. |
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My first thoughts are, extremely hot factory load (experienced this myself last hunting season with Federal ammo) or a blockage in the barrel. Is there a chance that something was either left in the barrel from the last shooting session (broken shell) or maybe something from cleaning the rifle? It seems odd that the bullet looks almost completely seated, yet all the pressure seemed to go backwards and not out the barrel.
Your brother is extremely lucky, any one of those chunks of brass or aluminum could of found their way in some flesh, or God forbid, an eye. |
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Quoted:
Why is there loose gunpowder all over the towel that these pictures were taken on? Why wasn't this posted by "your brother"? Is he 9 years old? How can you peel the bottom section of the bolt carrier clean off without destroying your entire gas system also? Yes, I see the rear gas ring out of its seat. Why does it look like this mal-treated weapon has never been lubricated in its life? I'd like to see a lot more credibility in this thread. That is an excellent post. And that is the driest gun ive ever seen, i u run it like that i wonder what kind of cleaning schedule it has. Any way improper cleaning could cause this? |
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Sorry for the strident commentary in my previous posts. You can't imagine how scary this kind of thing is to a mfg. Thanks for filling in some gaps left in the story.
The bottom of the bolt carrier is designed to peel off as a pressure relief in the event of catastrophic overpressure like probably happened here. I've heard of a similar case that didn't blow up the gas tube also. The simplest 2 explanations for this one are: 1. Obstruction in the barrel (out past the gas port), which could, for example, be excessive corrosion based on the lack of lube 2. Defective ammo (such as a magnum charged primer or spherical powder instead of rod or fraudulent supplier...; note that lots of people use PRVI Partisan ammo without problems) |
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I've never heard of a AR blowing up and having it blamed on it being too "dry". Malf's yes, kabooms, no. It doesn't even look all that dirty.
I wouldn't think a chrome bore would corrode enough to kaboom the receiver, it would have to have corn growing in it or something. What I am wondering is if there was some kind of obstruction just part the chamber, this was the first shot after all, maybe something got lodged in it without the owner noticing or the bullet was pushed back into the case and increased the pressure. |
| It wasn't posted by my brother because hes working today so I went ahead and posted it for him. As for the gunpowder on the towel I knocked some over in accident and just went ahead and took the pictures anyway. And yes it's dry because I had wiped it all down. It was NOT this dry when fired trust me. It's far from mistreated or abused. Also there was nothing in the barrel I'm positive. And the bullet did leave the barrel. |
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Quoted:
It wasn't posted by my brother because hes working today so I went ahead and posted it for him. As for the gunpowder on the towel I knocked some over in accident and just went ahead and took the pictures anyway. And yes it's dry because I had wiped it all down. It was NOT this dry when fired trust me. It's far from mistreated or abused. Also there was nothing in the barrel I'm positive. And the bullet did leave the barrel. If that gun was well lubed,it would have taken more than a simple wipe down to get it that dry.Just sayin.... |
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That is a nasty KB, sorry about your luck and glad no one was hurt!
The bolt lugs look surprisingly good (to me) for having KB'd in battery. Most pics I see usually have some lug failure evident. Who knows. Not sure why some of the comments seem accusatory towards the OP.... he was upfront stating that doublestar was giving him great CS, so he's not trashing anyone...  If he says the bore was clear, I guess I'm gonna believe him. Either way, no skin off my nose. 
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Quoted:
That is a nasty KB, sorry about your luck and glad no one was hurt! The bolt lugs look surprisingly good (to me) for having KB'd in battery. Most pics I see usually have some lug failure evident. Who knows. Not sure why some of the comments seem accusatory towards the OP.... he was upfront stating that doublestar was giving him great CS, so he's not trashing anyone... If he says the bore was clear, I guess I'm gonna believe him. Either way, no skin off my nose. Almost makes me wonder if the primer was still completely in the case as it was going into battery. Edit- Squib is the most common cause of a KB. |
| Saw pretty much the same thing happen to one of our range m16s, it was caused by crap in the barrel, someone had droped it in the muddy gravel and it turned into a concrete plug!! no one was hurt but the guy on the line that it happened to got to go home and change his pants!! i would bet all the money in my wallet that the same thing happened here!! i have pics of it somewhere i will try and find them! |
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Doesnt look inconsistant with the other blown up AR's Ive seen. Its almost always the ammo.
That ammo? It was produced in a country that was fighting a civil war from 1991 until 1995. In the last 16-years they may have rebuilt their industry to the point that their manufacturing standards are acceptable. But you stated you bought the ammo years ago. The guy who loaded that ammo may have been murdering his neighbors because they were the wrong religion just a few years prior. Not really the guy i trust to manufacture my ammunition. But we all pay our money and take our chances. Companies as reputable as black hills, federal and winchester have blown up their fair share of aguns with out of spec ammo as well. |
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Quoted:
Sorry for the strident commentary in my previous posts. You can't imagine how scary this kind of thing is to a mfg. Thanks for filling in some gaps left in the story. The bottom of the bolt carrier is designed to peel off as a pressure relief in the event of catastrophic overpressure like probably happened here. I've heard of a similar case that didn't blow up the gas tube also. The simplest 2 explanations for this one are: 1. Obstruction in the barrel (out past the gas port), which could, for example, be excessive corrosion based on the lack of lube 2. Defective ammo (such as a magnum charged primer or spherical powder instead of rod or fraudulent supplier...; note that lots of people use PRVI Partisan ammo without problems) Seriously? |
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Quoted:
Why is there loose gunpowder all over the towel that these pictures were taken on? Why wasn't this posted by "your brother"? Is he 9 years old? How can you peel the bottom section of the bolt carrier clean off without destroying your entire gas system also? Yes, I see the rear gas ring out of its seat. Why does it look like this mal-treated weapon has never been lubricated in its life? I'd like to see a lot more credibility in this thread. Quoted:
Sorry for the strident commentary in my previous posts. You can't imagine how scary this kind of thing is to a mfg. Thanks for filling in some gaps left in the story. The bottom of the bolt carrier is designed to peel off as a pressure relief in the event of catastrophic overpressure like probably happened here. I've heard of a similar case that didn't blow up the gas tube also. The simplest 2 explanations for this one are: 1. Obstruction in the barrel (out past the gas port), which could, for example, be excessive corrosion based on the lack of lube 2. Defective ammo (such as a magnum charged primer or spherical powder instead of rod or fraudulent supplier...; note that lots of people use PRVI Partisan ammo without problems) Not tracking on this. Looks like you were skeptical and then came back and provided an answer to your own question after maybe conferring with someone else? Either way I've never heard of this particular "safety" feature; can you point me in a direction for design history/data to support this assertion? I'm very interested to read up on it. Thanks. |
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I've built some frankenguns before and have never had this happen. From different barrels/bolts/uppers/lower. From at least 6 different companys between guns.
When I do have a KB I will post pics for sure. As far as im concerned 95% of the time I think it is ammo related. Just MYOP! |
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I agree with most on here that it is most likely either the result of a barrel obstruction or bad ammo. Two factors lead me to believe that an obstruction is more likely:
1. It was the first round fired. 2. With any powder that works well in .223/5.56 it is pretty hard to generate the pressures necessary to cause catastrophic failure like this. Yes, it is very easy to exceed SAAMI limits but those limits are way below what is required to blow a rifle up. Those SAAMI limits incorporate very large factors of safety (probably on the order of 2x or greater). In order to do this with an improper powder charge, you pretty much have to load the wrong powder. The round that caused this was part of a large batch of manufactured ammunition. Hard to imagine how a manufacturer would wind up putting the wrong powder in one of a very large lot of rounds. edit: I am also guessing that if the case head separated the primer would not have been blown out –– but that is just a guess. Anyway, here is my reasoning: if the case head separated, it would have acted as a pressure relief valve in front of the primer and the resulting gases would have been forced back into the bolt from around the outside of the case head. Therefore, the primer would not have been ejected. Just a guess though. |
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Quoted:
2. With any powder that works well in .223/5.56 it is pretty hard to generate the pressures necessary to cause catastrophic failure like this. We have seen a bunch of rifles blown up by bad ammo recently. Hell three police carbines with Winchester Ranger and Federal XM193 recently. You can fit more than enough powder in a .223 case to blow a rifle up. Hell a standard .223 charge with a bad cartridge case will do it. Case head failure will kill your mag, mag catch, bolt, extractor, bolt carrier and peel your upper like a bannana. If your lucky it wont bow the mag well too bad and you'll be able to salvage the lower. I see nothing to indicate brl obstruction. |
| I'm no expert, but it doesn't look like the bolt was locked. There doesn't appear to have been any extraction damage to the cartridge or bolt. This make me think that there may have been something on the face of the bolt that detonated the primer as the bolt seated the catridge without the cartridge ever seating against the bolt face or under the extractor and without the bolt turning into lock. Without the case head being fully protected, there could be violent primer venting like in the photo, especially if it was peirced. |
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Quoted:
Quoted:
2. With any powder that works well in .223/5.56 it is pretty hard to generate the pressures necessary to cause catastrophic failure like this. We have seen a bunch of rifles blown up by bad ammo recently. Hell three police carbines with Winchester Ranger and Federal XM193 recently. You can fit more than enough powder in a .223 case to blow a rifle up. Hell a standard .223 charge with a bad cartridge case will do it. Case head failure will kill your mag, mag catch, bolt, extractor, bolt carrier and peel your upper like a bannana. If your lucky it wont bow the mag well too bad and you'll be able to salvage the lower. I see nothing to indicate brl obstruction. This! An obstruction would have bulged the barrel at a minimum. |
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Quoted: Sorry for the strident commentary in my previous posts. You can't imagine how scary this kind of thing is to a mfg. Thanks for filling in some gaps left in the story. The bottom of the bolt carrier is designed to peel off as a pressure relief in the event of catastrophic overpressure like probably happened here. I've heard of a similar case that didn't blow up the gas tube also. The simplest 2 explanations for this one are: 1. Obstruction in the barrel (out past the gas port), which could, for example, be excessive corrosion based on the lack of lube 2. Defective ammo (such as a magnum charged primer or spherical powder instead of rod or fraudulent supplier...; note that lots of people use PRVI Partisan ammo without problems) Or defective brass. The unsupported area of the case needs to be solid brass. the cartridge sticks out of the chamber about 0.155". Some brass may have thin webs. Using a magnum primer will not cause a case head failure with proper charge. It can cause the primer pocket to be enlarged which is itself a problem. Case head failures in proper brass is a sign of pressures over 70.000 PSI. Since the peak pressure happens right after the bullet starts moving and drops off rapidly, bursting the gas tube is nearly impossible. |
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Quoted: .. How can you peel the bottom section of the bolt carrier clean off without destroying your entire gas system also? Yes, I see the rear gas ring out of its seat. Why does it look like this mal-treated weapon has never been lubricated in its life? .. This is a case head failure. The carrier isn't designed for 50,000+ PSI running down the bolt's firing pin hole, it is designed for 15,000 PSI choked by the barrel's gas port and cooled by the gas tube. I've seen gas tubes glowing red hot that didn't fail, meaning the gas tube pressure is less than 5,000 PSI if the gas tube is made of typical superalloy (Hastelloy, Inconel 625 etc). Rifle isn't rusty. Rifle was working for 600+ rounds. Nearly every case head failure results in a cracked bolt. |
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Quoted:
Why is there loose gunpowder all over the towel that these pictures were taken on? Why wasn't this posted by "your brother"? Is he 9 years old? How can you peel the bottom section of the bolt carrier clean off without destroying your entire gas system also? Yes, I see the rear gas ring out of its seat. Why does it look like this mal-treated weapon has never been lubricated in its life? I'd like to see a lot more credibility in this thread. Harsh, especially coming from an "Industry Partner". Sounds a lot like just the type of person I would never do business with. Secondly, if you don't know what you're talking about, please do not pollute these threads with mis-information just to feel like you do. We're dealing with things that go boom, bad information can kill. Guessing wildly is not an informed diagnosis. |
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Quoted:
2. Defective ammo (such as a magnum charged primer or spherical powder instead of rod or fraudulent supplier...; note that lots of people use PRVI Partisan ammo without problems) Could you elaborate on the above? CCI #41 primers are commonly and safely used in .223 ammo, as are spherical powders. |
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