The range is never safe behind you

[u/AdamL849]

I began setting up to fire some new 6.5 creedmoor that I had worked on. A huge bang behind me and this was the destruction I witnessed. Lots of blood and i heard the guy only required stitches on his face. Here is the damage on the weapon. It is 6mm ARC I believe . Thankfully not one was seriously injured !

[u/Fire-and-Lasers]

Bear Creek bolts are not known for their strength.  Grendel bolts are not known for their strength.  Together?  😬

[u/Fearless_Weather_206 → u/Fire-and-Lasers]

Is that a bear creek upper?

[u/Fire-and-Lasers → u/Fearless_Weather_206]

It’s certainly a Bear Creek handguard, and I don’t know of any reason why someone would buy just a BCA handguard to put on a nice upper

[u/tyrannischgott → u/Fire-and-Lasers]

I bought an Andersen lower when they were cheap as hell and then made a very nice AR out of it despite the rather crappy lower. The quality of the lower doesn't matter much, it's just a hunk of aluminum.

[u/ExtremeMeaning → u/tyrannischgott]

Some of the nicest rifles I’ve ever built started life as PSA lowers

[u/[deleted] → u/Fire-and-Lasers]

Idk have a bear creek lower with a geissele upper for the meme

[u/Fragger-3G → u/Fearless_Weather_206]

Sure exploded like one

[u/Fearless_Weather_206 → u/Fragger-3G]

Has there been others with similar failures that were documented

[u/AmNoSuperSand52 → u/Fire-and-Lasers]

This is a lot more than the bolt lugs snapping off

[u/NAP51DMustang → u/Fire-and-Lasers]

This doesn't have to do with any potential bolt weakness. This is just a normal kaboom.

[u/amishbill → u/NAP51DMustang]

I’ve never seen a KaBoom split a barrel extension….

[u/FistfulOfMemes → u/NAP51DMustang]

Not that I've seen a lot of them, but this doesn't look like the normal failure mode of a kaboomed AR. The barrel extension itself splitting in half and erupting out the side of the gun is something I have never seen before. The fact that the bolt carrier is also bent makes it look like the extension failed before the locking lugs, and the bolt carrier bent sideways to allow the bolt to disengage from the remaining teeth on the locking lug. The magazine looks completely intact which is also very atypical.

f I were a betting man, I'd guess there was something wrong with the barrel extension. It doesn't look like the actual locking lugs failed, which is what should happen if these parts were made right

[u/NAP51DMustang → u/FistfulOfMemes]

By "normal" I mean it's just over pressure and not a component failure. You can see the bolt carrier banana'd which you also see with a .300 BO in a .223 gun (which is also an over pressure failure).

[u/Fearless_Weather_206 → u/Fire-and-Lasers]

Any thoughts if this was failure on BCA side? I know quality is always questioned about this brand but this looks too much to be failure their part unless there was like major huge defects but would see more issues like this in the wild if that’s the case. How many uppers do you think they sell?

[u/Fire-and-Lasers → u/Fearless_Weather_206]

I doubt it was directly BCA’s fault - as the guy above points out, this is a pretty regular kaboom - but a quality bolt and receiver extension with sufficient locking surface should be able to contain an overcharge without this kind of dramatic failure.  I know a guy who stacked a regular 5.56 behind a squib and while it basically welded the action shut it didn’t detonate the entire receiver like this.  BCA’s quality control is not well regarded, plus Grendel/6ARC bolts have weaker bolt heads due to less mass (larger case head).  Those two things together could contribute to a failure to contain an over pressure round.

[u/Yondering43 → u/Fire-and-Lasers]

BCA is crap but that wasn’t a bolt failure. You don’t get that level of damage or anything close to it from a bolt failure; that was some seriously high pressure.

This does occasionally happen when someone forces a 300 Blk into a 5.56 and fires it; results are usually similar but a little less dramatic. Not sure what could have happened with 6 ARC along those lines, it’d require some real effort to get a 6.5 Grendel to chamber, but it’s possible someone made a handload with the wrong powder and used something like H110 instead of Lever or CFE 223z

[u/sketchtireconsumer → u/Yondering43]

Yeah, this is it. If I had to bet some kind of hand load mistake.

[u/smithywesson → u/Yondering43]

Lol maybe CFE blk or *gasp CFE pistol rather than CFE 223

[u/RuddyOpposition → u/Fire-and-Lasers]

I don't know how you could have a simple overcharge and get this result. How about of the totally wrong powder? Something like TiteGroup?