Colt Expanse Kaboom

[ww2farmer]

You do know that a squib is an ammo problem, right?

Yes..................and your point? I think anyone not trying to be a douche bag would comprehend what I was saying, even if I didn't say it exactly the way you wanted to hear it.

[SeriousStudent]

My point would be it's a bad idea to talk smack to an Industry Professional or Moderator on M4C. Stickman is both.

Ponder that while you are on vacation.

[Kdubya]

Can someone link to the thread on arf?

I've been searching for it as well, and can't find it on ARFCOM. I did find it on Calguns and LF. IG was referenced in the thread on LF. That same thread had some pretty good technical commentary from a few members. So maybe IG misspoke; saying ARFCOM but meaning to reference LF?

[vicious_cb]

Anyone know the specs of expanse line upper receivers? Are they 7075T6 Al because ARs are usually pretty good at handling kabooms with most of the force being blown down the magazine well and avoiding shooter injury.

[Todd.K]

When it's bad enough the carrier splits, that will crack open the upper.

[T2C]

After reviewing the photographs again and paying close attention to the damaged brass, I suspect a combination of two things caused this issue: 1) Excessive headspace with the original bolt installed and 2) High pressure ammunition.

When the firing pin does not ignite the primer on a well worn rifle, the first thing I check after a thorough cleaning is headspace.

[Kdubya]

Anyone know the specs of expanse line upper receivers? Are they 7075T6 Al because ARs are usually pretty good at handling kabooms with most of the force being blown down the magazine well and avoiding shooter injury.

It appears the current production is 7075-T6. OP mentioned this was an older version without the FA. So, it's possible the construction was different for that iteration of the Expanse. Still, I'd be surprised if the KB rifle wasn't 7075-T6.

I'm certainly not the SME that is going to provide answers here. However, I like to follow these stories in hopes of avoiding a KB of my own. One common theme with these stories is the pattern of events.

The rifle malfunctions.
The shooter takes action to try to force it back into service.
Kaboom!

Often, those first two steps are repeated a couple of times before the third event in that sequence. It seems like the Rifle is always trying to say, "Stop! Something's not right here. Take a step back and do some investigating." I don't blame the shooters in those situations. Experiencing an occasional malfunction is just a reality for us. And, in those situations, we've conditioned ourselves to do X, Y, and/or Z until the rifle starts firing again. The issue I find is that we always seem to be in a rush to get the rifle back into service. Why? In all these KB stories, I don't recall any that were "life or death" scenarios. Instances where the shooter was facing a hostile situation; needing to return fire. There was one a while back where a guy was in the middle of a competition and caught a squib. He tried to tap and rack a new round like 3-4 times before the KB ended up happening. I get racing against the clock, but at the point of 3-4 failures the shooter already is probably out of the running. It just always seems like the KB victim is in a rush. Not to figure out the issue, but to make the rifle go bang again.

Honestly, I don't know if slowing down and investigating would have altered history in all these KB scenarios. But I can't imagine it would have made them any worse. Personally, I've decided to approach malfunctions with a little more caution. Take a couple extra seconds in the moment to really inventory the situation. Don't hesitate to break the rifle down and inspect everything. As shooters, I almost think we need to change our approach. Training ourselves to do X, Y, or Z to get the firearm running again has its place in shooting. But in a non-combat scenario, it seems like the wrong approach. Getting a rifle firing again doesn't mean the problem's been fixed. Instead shouldn't we train for diagnosing the issue? That the goal is not to fire the next round, but instead to determine why the previous one failed. Am I crazy for taking this approach?

[Iraqgunz]

I could probably dig up at least a dozen pics of similar kabooms from multiple companies that were similar.

Anyone know the specs of expanse line upper receivers? Are they 7075T6 Al because ARs are usually pretty good at handling kabooms with most of the force being blown down the magazine well and avoiding shooter injury.

[Amicus]

This was very interesting. Personally, and without knowing anything beyond this thread, I think T2C has the best notion.

But, that being said, I have a case of this lot. I guess it's not seeing the light of day until someone figures this out.

Any suggestions, or is it just too early?

[Butch]

The rifle malfunctions.
The shooter takes action to try to force it back into service.
Kaboom!

I'm totally on board with this. I too see this relation when watching KB video. Take this guy as an example, He's rushing to get the rifle back in service like his position is about to be overrun. I don't see a problem to error on the side of caution and inspect the rifle more throughly. Now he'll spend the rest of his life bashing Colt.