http://www.ar15.com/forums/topic.html?b=3&f=118&t=534856&page=1
With the few kb’s and suspect ammo threads that have been going around I thought I’d add to the pile.
It doesn’t seem clear as to what the actual cause was yet, but its worth keeping eye on.
It most likely wasn’t an ammo issue, but a build quality issue.
C4
possible barrel obstruction? It blew the gas rings and the bottom of the BCG where all the gas impinges. Wheres the cam pin at
Does Double Star even use 5.56 chambers, or do they use .223 like other lower tier rifles? Not the cause, but probably didn’t help with the overpressure.
I like how the guys says that doublestar is great because they are going to fix it and send a new one. Maybe I would look else were for a new gun, but then again it was the guys fault the gun blew up not the gun ( mostly likely).
Agree with possible barrel obstruction, reloading issue, projectile compressed back into the case…Pressure way to high.
The cam pin is still in the bolt. You can see the bottom of it in the photos. Some of the photo angles/lighting make it appear as if the pin is missing.
I’m going with quality of the upper. And who the hell is double star never even heard of the damn company.
They have been around for awhile They also make a 1911.
[b]DoubleStar[/b]
[b]DoubleStar search on m4carbine.net[/b]
No, I don’t own any of their rifles or pistols.
Ever notice that you always here about catastrophic phailures, ‘‘kabooms’’ and other crap on TOS, but you almost ever hear about a dude’s Colt LE6940 blow up here.
Makes you wonder.
Yes, most strange. 
Oliver Stone told me there is a conspiracy to cover up all the Colt, BCM, Daniels, and Noveske failures, so we can preserve our illusions of quality. I’m sure he’s right. After all, he says that even though he hates guns, if he owned one, it would be just as good as a Colt.
:rolleyes:
Colts can blow up too but most of the time it’s ammo related. I believe it was Pat Rogers that had a LE6940 blow up either last year or the year before in class. IIRC Colt replaced it and I can’t remember what caused it.
I have a Doublestar M4gery that that I bought used for good price during the hysteria. It has a couple to a few thousand rounds through it with out issue. But then, I put a BCM BCG in it and shelved the original.
Regardless of upper brand, that was a lot of pressure, to cause that. Its either from a barrel obstruction, pistol powder in the case, or possibly the bullet shoved ALL the way back into the case, and loose past the neck, upon chambering. Look at the pressure that caused the sides of the upper to bulge and break, the extractor looks peeled back as seen in most over pressure failures, and it looks like the bolt, on its way back, was forced downward, with the blast that sought the easiest way out (through the magwell), and the downward forced bolt broke out the bottom of the carrier. This is not simply a case of a faulty carrier. It looks like you can see part of the mangled, case, with no base, still in the chamber.
While I don’t own a single thing made by doublestar, and never will, Colts blow up too. I saw pictures of a 6920 that was in use in a training class, using XM193, that looked very similar to this doublestar, only it had way more damage. The left side of the upper was completely blown out the side, and the bolt was almost unrecognizeable. Any gun will blow when you have an over pressure situation like that.
Glad no one got hurt. Rifles can be replaced.
I’d like someone who thinks it is the rifle to explain how/what part of the rifle failed and caused the KB.
The chamber pressure was too high and here is the simple evidence:
Pic #2 shows the case with typical high pressure failure where the brass flowed under the extractor.
Pics #2 and #3 show brass colored vapor deposits on the side of the bolt. Brass does not turn into a liquid at normal chamber pressures.
A bore obstruction would have to be close to the chamber to cause that much pressure.
Same thing happens when a Glock Kabizzles… :eek:
Gee a gun blows up when the chamber pressure is over 70k!!! OMG!! 
did this thing fire out of battery? If it was high pressure wouldnt there be more damage to the barrel extension and bolt face/lugs?
No, the design of the AR does not allow the firing pin to contact the primer until the bolt is locked. OBD would not produce as much damage because the pressure is not as high.
The lugs do not fail in an AR KB. You have to think about this as a liquid escaping and flowing out the easiest path, not an explosion where the shock wave causes the damage.
What was the issue with that ammo, do you remember?
BTW I decided against a Doublestar when Larry Vickers used it for his mud/sand/water torture tests on his TV show. He wouldn’t treat his Daniel Defense M4 like that, but instead let the Doublestar take the beating!