BCL 102 catastrophic failure
- Thread starter slash547
- Start date
wapitiwhacker
CGN Regular
- Location
- East Kootenay B.C.
Thank you for sharing the story. As someone new to the AR platform this thread has been a good learning experience.
Mine locked up like that on the 3 rd discharge after 3 failure to feeds. Not all shots were consecutive. They replaced my rifle as well. I did find the gouging on my receiver was caused by the firing pin retainer walking out. With only 3 shots it didn’t do as much damage as the OP’s did. My barrel extension was improperly indexed as well.
Untitled by Eric V, on Flickr
Untitled by Eric V, on Flickr
They're selling them at Cabela's now. They'll be fine.
This is not an AR problem, this is a BCL problem. Don't judge the platform based on what you read about BCL products.
Why? They've been selling problems for years, hasn't slowed them down at all.
Who's going to prove anything? BCL has the rifle now, my bet is we never hear anything about it from them other than Slash may get a new rifle. They won't make it public that it was their own sloppy assembly and bad QC that led to another one of their rifles failing.
When are people going to learn to stop buying BCL?
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Ya. That doesn't stop people from using Glocks. This is probably has to do with ammo. Even an AR15 with a free float fire pin will have a out if battery discharge if you have a poorly seated match primer.
I stopped buying NEA/BCL last year. Gave them another chance after the creation of BCL but same old crap : poor QC, off-spec dimensions, and never-ending horror stories of issues. Can't support a business like that regardless if it's Canadian or not.
I have no idea why you would think this has anything to do with ammo. The primer strike was solid and the OP said he pulled the trigger,so it wasn't a slam fire. The primer was also not blown out or flattened due to overpressure.
There will be a slight error here due to parallax, but the barrel extension was misaligned by about 11 degrees. There are 8 lugs. 360/8= 45 degree spacing between lugs. Assuming normal lock-up rotates the bolt halfway to the next lug (22.5 degrees) then there would be about 50% of the designed amount of contact between the bolt lugs and the barrel extensions lugs.
Then, in addition to that the bolt lugs were chamfered, further reducing contact by probably another 50%. So the bolt was barely locked up at all; maybe 25% of the surface of the lugs were in contact in an ideal case.
Then you add the clearances and tolerances for all the moving parts. Bolt carrier to cam pin, cam pin to bolt, bolt into barrel extension. You might gain or lose several degrees of rotation there.
Then you add some wear, maybe the cam pin or cam pin track was taking a beating due to the bolt unlocking too early or hitting the barrel extension upon closing.
There's your kaboom.
Then, in addition to that the bolt lugs were chamfered, further reducing contact by probably another 50%. So the bolt was barely locked up at all; maybe 25% of the surface of the lugs were in contact in an ideal case.
Then you add the clearances and tolerances for all the moving parts. Bolt carrier to cam pin, cam pin to bolt, bolt into barrel extension. You might gain or lose several degrees of rotation there.
Then you add some wear, maybe the cam pin or cam pin track was taking a beating due to the bolt unlocking too early or hitting the barrel extension upon closing.
There's your kaboom.
- Location
- Maple Ridge BC
For sure this barrel was at least slightly off it's correct index. Even if the index pin wasn't quite driven under .. yet.
These stove pipes were probably caused by the locking lugs binding as they were entering. Upon locking, the lugs were just barely engaged at the corners of the chamfers.. then bammo, the lugs slipped, bolts is slammed back bending the carrier lug as well as spinning the barrel as the chamfers slipped past eachother.
This is purely a design and assembly issue.
Those lugs do not need such a large chamfer, there is no need other than to help them self align into a poorly timed extension. On the flip side the large chamfer means the timing is even more critical to keep it locked up.
Best solution is minimal chamfer, with carefully timed extension.
As I see another photo in this thread of another poorly timed extension that was just on the verge of tossing its guts.
I'm not going to simply toss bcl under the bus, I'd reccomend everyone checks all brands of rifles for correctly indexed extensions. This is easy to skip through and brands qc department.
These stove pipes were probably caused by the locking lugs binding as they were entering. Upon locking, the lugs were just barely engaged at the corners of the chamfers.. then bammo, the lugs slipped, bolts is slammed back bending the carrier lug as well as spinning the barrel as the chamfers slipped past eachother.
This is purely a design and assembly issue.
Those lugs do not need such a large chamfer, there is no need other than to help them self align into a poorly timed extension. On the flip side the large chamfer means the timing is even more critical to keep it locked up.
Best solution is minimal chamfer, with carefully timed extension.
As I see another photo in this thread of another poorly timed extension that was just on the verge of tossing its guts.
I'm not going to simply toss bcl under the bus, I'd reccomend everyone checks all brands of rifles for correctly indexed extensions. This is easy to skip through and brands qc department.
wapitiwhacker
CGN Regular
- Location
- East Kootenay B.C.
Oh, I realize that. The discussion just brought to light a lot about the mechanics of the platform that weren't immediately obvious to me.
Maybe more correct.
