AR kaboom

[MOT]

So I blew up my AR today.
Rifle is a Windham weaponry mid length.
I’ve put about 2-3000 rounds through it without complication.
After about the sixth shot today it kabooms.
Ammo is some green tip 62gr steel core.
I think the lower is ok but the upper is jacked.
Will try to post pictures.
Thoughts..?
I appreciate the experience you all bring.

 

[Longinvs]

Who's the ammo manufacturer?

 

[Sunshine_Shooter]

Do you own a .300 BLK?

 

[Yondering]

A 300 Blk round in a 5.56 chamber will do that. Don't know if that's what happened to yours but a number of people have done that over the last few years.

It would need a pretty severe overload to do that with normal 5.56 ammo though.

 

[MOT]

Sorry tried to get a picture of the box.
Federal American eagle xm855bk150
5.56

 

[MOT]

And no I don’t own a 300 blk

 

[David Mayeur]

1. Did you keep the case that blew it?
2. Was there a squib?

 

[MOT]

The round hit the target. The barrel shows no bulges that I can find. The case is still in the chamber. I haven’t been able to get the bolt and carrier out. Taking it to the smith today.

 

[Longinvs]

So I saw this a few weeks back with some IMI green tip. It was in one of the magpul branded midlength M&Ps. Gun turned into a grenade, customer still had the case head and it was certainly a 5.56. Same thing, wrecked the upper and the lower, the barrel itself was fine but the extension was damaged. He had been shooting so it likely wasn't a reassembly issue and it was not a squib. Smith told him to talk to IMI or they would sell him another rifle at cost. Is there a possibility that Federal over charged a round? I'm not familiar with industrial scale ammo production so I don't know what can get caught or how.

 

[MOT]

Took the gun to the smith. After some creative hack sawing we were able to get the bolt and carrier out. Both were cracked lengthwise and the barrel extension was also cracked.
Turns out it was in fact a squib. I guess it must’ve been the previous round that got launched into the target. I had no malfunction previous to it blowing up which is why I didn’t suspect a squib.

 

[Sunshine_Shooter]

If the squib stopped after it passed the gas port, it would cycle the gun fine, if not more forcefully than normal. I don't know if you'd be able to feel it or not (it's yet to happen to me).

I'd definitely call Federal and have them replace your gun. They've probably got insurance for this sort of thing.

 

[Yondering]

Is there a possibility that Federal over charged a round? I'm not familiar with industrial scale ammo production so I don't know what can get caught or how.

"over charged" maybe, but not enough to cause that sort of damage unless they used the wrong powder for that particular round. (not likely) A milspec 5.56 load is a different thing than a lot of pistol cartridges that have the potential for a double charge because of lots of case capacity relative to the small powder charge. That situation isn't possible with something like M855 loads.

 

[Gypsy EDC]

"over charged" maybe, but not enough to cause that sort of damage unless they used the wrong powder for that particular round. (not likely) A milspec 5.56 load is a different thing than a lot of pistol cartridges that have the potential for a double charge because of lots of case capacity relative to the small powder charge. That situation isn't possible with something like M855 loads.

More likely an undercharged round followed by a normal charge. I've only experienced squibs in my own reloads when trying to make stuff very quiet, or when I was building a subsonic 300 blackout load prior to there being load data out there.