BCL 102 catastrophic failure

Not sure if this matters, but a lot of the previous feed issues with BCL was the cam pin dish in the upper was not to spec, and the cam pin head would make contact there when the bolt was locking up. It may have been in minimal or partial lock up.
The out of battery safety is the firing pin length, it's not suppose to be able to reach a primer unless fully in battery.
With the amount of "out of spec" stuff these guys produce, it's not a stretch they would put stuff out that could fire out of battery.
 
Looks like the gen 2 is compatible with the longer system, unlike the gen 1 I have on my stag which needed the short buffer, which is awesome. Guess I know which stock I’ll be buying next!

I tried a UBR Gen 2 on my 102 and the front threaded part of the buffer tube wasn't long enough to make contact with the buffer detent pin and the tube was, as mentioned. slightly longer than the BCL buffer tube. Depending on your load the slight extra length of the UBR buffer tube could make a difference in whether the OEM buffer itself hits the back of the tube.
 
Not sure if this matters, but a lot of the previous feed issues with BCL was the cam pin dish in the upper was not to spec, and the cam pin head would make contact there when the bolt was locking up. It may have been in minimal or partial lock up.
The out of battery safety is the firing pin length, it's not suppose to be able to reach a primer unless fully in battery.
With the amount of "out of spec" stuff these guys produce, it's not a stretch they would put stuff out that could fire out of battery.

very interesting. thank you. All you guys (ladies?) are awesome help and a wealth of knowledge!
 
Question about said cam pin. When removed, inspect it for deformation. I noticed my bcl cam pin has marring as if its a softer steel or something rubbing on the carrier groove

I can not get the bolt to rotate and engage so it will not clear the buffer tube hole and hence can not drop the lower down for a good look.
 
I read all his posts and that what was left of the case was found on the ground, ejected from the action. He stated he collected the brass from the day and all spent cases were accounted for. He also showed the two unfired rounds that stove piped. What he did not show or say is that any of the cases are missing a primer, fired or not. So I am not assuming a primer loose in the action or chamber is the culprit. It's something else. Wonder what inside the barrel extension and chamber throat look like

All primers are in the cases. I know, crazy. I believing the vacuum created and the case partially out imploded the neck. No idea if the neck separated given the deformation of the case. There is no material in the barrel and I can insert an empty case into the breach.
 
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I tried a UBR Gen 2 on my 102 and the front threaded part of the buffer tube wasn't long enough to make contact with the buffer detent pin and the tube was, as mentioned. slightly longer than the BCL buffer tube. Depending on your load the slight extra length of the UBR buffer tube could make a difference in whether the OEM buffer itself hits the back of the tube.

My UBR G2 tube landed on the detent pin fine. All torqued per Magpul instructions. Still not believing 5 mm difference in length is the culprit.
 
It looks as if the boltface counterbore is chamfered. The face of the barrel will also be chamfered. This means that a portion of the casehead is unsupported. If there is a defect in the cartridge case in this area, it will fail.
You mentioned that the bullet exited the barrel. This means that there was pressure at the gas port. The action tried to cycle.
 
Two lines on deformed case line up with the case neck so the end of this case did not separate
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The bottom of the case blew out 0.7" - does that mean this case was out of the breach that far? Could explain why the neck expanded that much and why the bolt lugs are not damaged??
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Tear down the rest of those reloads, is it possible one/some got pistol powder in them? Sometimes guys forget about the charge in the dispenser.

We ought to start a thread with KB stories...

There's the guy who got distracted reloading 38spl and 44mag. Next thing you know, he's filling 44 cases with 24gr of Titegroup... and blew apart is M29
(That's probably why I won't shoot other people's reload)

Guy breaking-in his new BR gun, cleaning between shots... talks with the guy on the next bench and didn't notice that his nylon brush somehow unscrewed... So much for that rifle...

"new" shooter getting in the game, buys a used target rifle along with some reloaded rounds and loading data for it... the ammo worked good in the target rifle, decided to give a try in his hunting rifle... wasn't such a good idea.
 
Umm well you are SOL if you were reloading.
But you need to get the BCG out in one peice see if it's a firing pin issues.
Ask bcl in writing docthat the bolt far specs and the fireing pin lenight is and then see if that is correct.
Fyi this is one of the reasons that the pros ask for the whole gun back when there is an issue.
 
It looks as if the boltface counterbore is chamfered. The face of the barrel will also be chamfered. This means that a portion of the casehead is unsupported. If there is a defect in the cartridge case in this area, it will fail.
You mentioned that the bullet exited the barrel. This means that there was pressure at the gas port. The action tried to cycle.

Good eye...that looks odd, I've never seen any kind of AR bolt like that.
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The bottom of the case blew out 0.7" - does that mean this case was out of the breach that far? Could explain why the neck expanded that much and why the bolt lugs are not damaged??



its not uncommon to have over 1/8 inch unsupported case wall on a rifle these days, my ruger GSS had 3/16 above the case head (of actual wall) unsupported on 2/3 the case. take one guess were it blew out?

this kinda looks like it was pulling the still exploding case out of the chamber... hence the level of destruction and the fact that the BCG is jammed in the tube.
 
so you think it ruptured in the chamber with the bolt closed?
might explain the rolled in case wall..... if the bullet had not yet left the barrel the case head rupture might have just created enough vacuum to implode the case like that..... maybe?
that's the part that still stumps me.



All primers are in the cases. I know, crazy. I believing the vacuum created and the case partially out imploded the neck. No idea if the neck separated given the deformation of the case. There is no material in the barrel and I can insert an empty case into the breach.

Pretty sure there is never a vaccuum created at any point of the cycle regardless of case failure. We're dealing with pressures in the 55000-60000 psi range, I can't explain what happened to the brass there but it wasn't from a negative pressure in the rifle chamber.

Have you contacted BCL yet?
Request warranty replacement of the entire rifle and don't mention that you were shooting handloads.
I would also break down all the remaining rounds you made and discard the powder.
Speaking of powder, I haven't seen a post yet where you mentioned which powder you were using.
You may want to take a little more time in the brass prep next time. Not saying brass prep was the problem but measuring one out of five is not good enough when loading for a semi auto when you're on your fifth firing for that brass.

Was this all matched brass that you've owned it's entire life of do you pick up brass at the range?
 
Pretty sure there is never a vaccuum created at any point of the cycle regardless of case failure. We're dealing with pressures in the 55000-60000 psi range, I can't explain what happened to the brass there but it wasn't from a negative pressure in the rifle chamber.

I totally hear ya on that. was merely brainstorming on what could cause the brass to implode like that as it looks sucked in vs formed in by a piece of debris. Also when I looked carefully at the very first pic that was posted, even the leading edge of what was left of the neck has an inward burr or rolled inward edge..... very confusing LOL
Generally , the pressure of normal operation expands the brass into the chamber..... doesn't implode it
 
BCL might be very interested in studying your rifle.
No doubt they have tested specimens to destruction, but having a look at yours should be of value to them.
By all means get in touch with them. They might replace the rifle, simply on the basis of good customer relations.
I would suggest that falsifying a warranty claim, lying about the use of handloaded ammunition might be unwise.
 
I doubt very much BCL does any testing... otherwise those beveled ejectors wouldn’t have made it out the door.

BCL has their customers pay full price to do the testing for them lol
 
I totally hear ya on that. was merely brainstorming on what could cause the brass to implode like that as it looks sucked in vs formed in by a piece of debris. Also when I looked carefully at the very first pic that was posted, even the leading edge of what was left of the neck has an inward burr or rolled inward edge..... very confusing LOL
Generally , the pressure of normal operation expands the brass into the chamber..... doesn't implode it

Did we ever get an answer as to if there is still a case neck stuck in the chamber?
If it did break off that would allow the gasses to get in around the remainder of the brass and crush it in. Just brainstorming as well, I've never seen anything like that before.
That primer looks like it was nearly punctured as well, might be a little too hot for this rifle.

What powder were you using? Even a mid book load can be too hot for some rifles like this, maybe the chamber was a little tight "match chamber", combined with maybe a less than ideal powder choice, maybe also combined with a little too long of brass, the tolerance stacking may have led to your kaboom.
My Modern Hunter (6.5CM) hates Hornady Superformance, will pierce primers, jams all the time, and groups like a shotgun, I handload using the same projectiles and it cycles perfectly and groups really nicely. Just an example of how finicky a semi auto can be when factory loads are too hot for a gun, same for reloading, a mid book load may still be too hot.

Also, stop loading lead tip bullets in your rifle, it's probably got nothing to do with what happened but semi auto's don't feed them well and the tip will get mushed a little as it goes in which will decrease accuracy.


BCL might be very interested in studying your rifle.
No doubt they have tested specimens to destruction, but having a look at yours should be of value to them.
By all means get in touch with them. They might replace the rifle, simply on the basis of good customer relations.
I would suggest that falsifying a warranty claim, lying about the use of handloaded ammunition might be unwise.

Maybe just don't volunteer the ammo info unless asked specifically about it.

I agree with Wall-mart greeter, I don't get the feeling they do any R&D at BCL, They've had way too many issues to believe they have any idea what they're doing there. That first batch of 77 gen 1 rifles must have had at least twenty with problems, in some of the pictures posted the issues were so obvious they should have never made it out of the shop.

When guys are buying a complete rifle and then stripping it down to the receiver and throwing out all the stock parts to build a new rifle just because it was the only affordable AR-10ish rifle on the market it should send a message to people with less experience that this is not a good product.

I doubt very much BCL does any testing... otherwise those beveled ejectors wouldn’t have made it out the door.

BCL has their customers pay full price to do the testing for them lol

The beveled ejector is more aerodynamic, it's just one of BCL's "improvements" :p
 
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