View Full Version : SBR Kaboom!
Recently I had a kaboom with my 12.5" BCM "Kino" SBR and I thought I would share it. I violated one of my principal rules which is to be careful of what ammo I shoot.
In this case the ammo was in use by the range where I do some part time work as a Range Safety Supervisor/Armorer.
The damage was pretty significant in that it split the LMT enhanced bolt carrier, damaged the extractor, bulged out the Vltor MUR-1A upper receiver and bent the firing pin retaining pin.
Earlier this evening I was finally able to tear it all down and inspect the barrel and chamber and I was unable to detect any other issues. It has been rebuilt (thanks to Four Peaks Armory in AZ and BCM) with the exact same components.
I think the damage could have been worse and I believe that the MUR upper and the LMT enhanced carrier may have limited the damage.
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This is a pic of the enhanced carrier with the key removed. You can see that there is a chamber of sorts which vents the gas to the left and right rather than directly down into the carrier.
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polymorpheous
07-11-13, 05:03
I know you probably were shooting suppressed also.
Did it take any damage?
That's some carnage. I take it nobody was hurt?
I guess it really shows to be careful about ammo.
What was the type/brand of ammo used if you don't mind me asking?
Glad you did not get seriously injured.
So no idea on the brand of ammo? Reloads?
The way that the carrier is split is impressive! Lot of pressure going on there.
C4
I gave him some "special" loads for locking too many threads here! :p
I gave him some "special" loads for locking too many threads here! :p
So you managed to squeeze 30g of 8208xbr and those 80g SMK's down to mag length:lol:
So you managed to squeeze 30g of 8208xbr and those 80g SMK's down to mag length:lol:
When I hand you ammo and say don't shoot this till I leave.... be affraid... be VERY affraid. :D
Seriously though.. I get this call from Mr. Gunzdamis going on about his gun blode to bits... and he finally... 5 minutes into the debrief... tells me it wasn't my ammo. What a dick.
Seriously though.. I get this call from Mr. Gunzdamis going on about his gun blode to bits... and he finally... 5 minutes into the debrief... tells me it wasn't my ammo. What a dick.
:haha:
I'm also wondering what ammo it was.
Good to NOT read of any bodily injury! What do you estimate round count to be on the BCG?
:haha:
I'm also wondering what ammo it was.
I can't remember the exact specs... I'll let the OP address that.
Only person more pissed than IG, was Mark. Ha
That's pretty cool how the enhanced carrier diffuses the gas. So very often premium products go the extra mile and we don't even know the detail put into the build.
This thread should be sub titled "Wear Eye Protection".
The "green stick" type fracture of the bolt carrier is common when a carbine goes high order as a result of case failure. The clearance cuts for the magazine feed lips on the carrier create the perfect weak link. The fact that energy created by the failure of the carrier is directed down, and not up or horizontal, is why I don't think we don't see significant injuries to the shooter as a result of the KB.
Did the floor plate on the magazine get spawned into a secondary projectile?
ScatmanCrothers
07-11-13, 12:01
After seeing the carrier it's pretty impressive the MUR only had the slight mushrooming that it did. I'd say it definitely took one for the team and kept the damage in-house.
Wow, IG glad your Okay. That's nasty looking. Thanks for posting.
HOLY CATS.
You can't get away that easy -- what brand ammo was it?
Glad you're OK.
I don't care how much one does the math, the chemistry never fails to amaze me!
The magazine was toast and we didn't locate the spring/follower. Only the base plate.
The "green stick" type fracture of the bolt carrier is common when a carbine goes high order as a result of case failure. The clearance cuts for the magazine feed lips on the carrier create the perfect weak link. The fact that energy created by the failure of the carrier is directed down, and not up or horizontal, is why I don't think we don't see significant injuries to the shooter as a result of the KB.
Did the floor plate on the magazine get spawned into a secondary projectile?
The bolt and upper had about 8K through it. The carrier was recently installed after a 6 month back order from LMT.
Good to NOT read of any bodily injury! What do you estimate round count to be on the BCG?
I cannot divulge the ammo company as they are aware of the situation and they are paying for all of the parts. The range purchased about 100K of this from them and I don't believe it is in common circulation.
K.L. Davis
07-11-13, 14:12
You killed one of my namesakes :mad:
I can say, from experience, that the MUR contained a lot of damage...
Hory Chit.
Glad you're ok, man.
You killed one of my namesakes :mad:
Just means you have to pay for it. :p
It's already been fixed and is ready to go.
You killed one of my namesakes :mad:
I can say, from experience, that the MUR contained a lot of damage...
It's already been fixed and is ready to go.
There's still emotional damages though. :p
That definitely sold me on a MUR.
I'm glad to hear you're ok!
I cannot divulge the ammo company as they are aware of the situation and they are paying for all of the parts. The range purchased about 100K of this from them and I don't believe it is in common circulation.
Understandable. It's good to hear the company is taking responsibility and covering the damages.
I guess 25 grains of Bullseye isn't the hot ticket.
Tonyparson
07-11-13, 15:48
I'm glad no one was hurt. I glad to hear the ammo company is taking care of the cost on the parts.
Glad you were not hurt. Just out of interest what were your thoughts as it happened? Had a ka-boom many years ago and my reaction was waaaaat happened, stare at gun, holy shit.:confused:
I wasn't shooting it someone else was. I heard the weird "pop" and knew something wasn't right. Then he turned and looked at me and I saw the raccoon face and I knew.......
Glad you were not hurt. Just out of interest what were your thoughts as it happened? Had a ka-boom many years ago and my reaction was waaaaat happened, stare at gun, holy shit.:confused:
I cannot divulge the ammo company as they are aware of the situation and they are paying for all of the parts. The range purchased about 100K of this from them and I don't believe it is in common circulation.
Does this mean that you can't name the company right now, or that you can't name them ever?
I have to check with that as I have the feeling that the people in St. George, UT may get upset if I mention it.
I am pretty sure that there is little of this ammo in circulation.
Does this mean that you can't name the company right now, or that you can't name them ever?
I wasn't shooting it someone else was. I heard the weird "pop" and knew something wasn't right. Then he turned and looked at me and I saw the raccoon face and I knew.......
Well IG I am again glad that you and everyone else is ok. I am very impressed with the equipment. In spite of what happend it's seems like at least the equip took one on the chin and now we all get a great idea on why to spend the extra money on top tier equip. I will be purchasing a MUR in the future with out a second thought.
Yes, it was suppressed. I haven't seen any visible damage.
I know you probably were shooting suppressed also.
Did it take any damage?
Gotta love IG. His rifle detonates and he looks at it as an opportunity to examine a Kaboom. Glad to hear the rifle is getting back to right and that no one was seriously hurt.
I'd hate to see what might have happened if this had occured in a crap AR. A quality weapon certainly saved some serious injury here.
Gotta love IG. His rifle detonates and he looks at it as an opportunity to examine a Kaboom. Glad to hear the rifle is getting back to right and that no one was seriously hurt.
Ditto from me!!! :D
^^^^^
Agree completely. Gotta be the first "we blew up my rifle, wanna see the pics?" thread ever, as opposed to the "<insert brand name of rifle> ARs are crap, my rifle Kaboomed!!!".
Especially when the majority of Kabooms seem to be ammo related and good equipment limits the damage.
The more I shoot, the more I realize its probably only a matter of time before something like this can happen to anyone who shoots a lot.
^^^^^
Agree completely. Gotta be the first "we blew up my rifle, wanna see the pics?" thread ever, as opposed to the "<insert brand name of rifle> ARs are crap, my rifle Kaboomed!!!".
Especially when the majority of Kabooms seem to be ammo related and good equipment limits the damage.
The more I shoot, the more I realize its probably only a matter of time before something like this can happen to anyone who shoots a lot.
Seems to me you are more likely to encounter a bad round before you hit the 20-40k it will take to shoot out your components
Seems to me you are more likely to encounter a bad round before you hit the 20-40k it will take to shoot out your components
Agree. Which is why I dislike "how long will my <insert quality firearm> last threads".
If you can shoot enough to wear it out, the cost of a second firearm is chump change.
Just another reason for me to keep buying MURs and MURs only. :)
Very interesting about the chamber LMT has made into their carrier that evenly channels the gas in 2 different directions. Honestly had no idea. Good to know. Am curious if all generations have this.
Sucks about the long wait IG on the e-carrier only to have it destroyed. Good thread and glad to see your Kino is up & running again.
-Jax
Extremely pleased that when all is said and done a fine learning experience is all that has come to pass. I am sure the were a few moments when the sphincter muscles twitched, but no accidental discharges followed.
Great post IG !
Fortunately I ordered two of them (one for my SBR and one for my 20" rifle) and my friends at Four Peaks Armory ordered 5 or so. They were more than willing to help me out with a new carrier and MUR upper.
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Just another reason for me to keep buying MURs and MURs only. :)
Very interesting about the channels LMT has made into their carrier. Honestly had no idea. Good to know. Am curious if all generations have this.
Sucks about the long wait IG on the e-carrier only to have it destroyed. Good thread and glad to see your Kino is up & running again.
-Jax
That definitely sold me on a MUR.
I'm glad to hear you're ok!
It's a pretty decent advert for sure. Good to hear no one was hurt.
justin_247
07-11-13, 23:34
Glad to hear you're OK!
Fortunately I ordered two of them (one for my SBR and one for my 20" rifle)...
An Enhanced Carrier in a rifle-length gas system? Can you tell us some more?
I remember Grant wrote up a thread once about his surprising experiences with the Enhanced Carriers, so this is just icing on the cake.
During my talk with 'Gunz, he mentioned that someone had a misfeed that resulted in bullet setback with that same remanufactured ammo and that the crimp looked odd.
IMO, bullet setback during chambering definitely could have caused the extremely high chamber pressure and resultant case failure / KB.
Not much I can add. I think I posted this info on one of the A5 threads. I ran my 20" FN barreled M16A5 with the Vltor -3 buffer and the enhanced carrier and it ran 100% with 4 different loads.
I believe it was M193 clone, Hornady Steel TAP, and a couple of others.
Glad to hear you're OK!
An Enhanced Carrier in a rifle-length gas system? Can you tell us some more?
I remember Grant wrote up a thread once about his surprising experiences with the Enhanced Carriers, so this is just icing on the cake.
As others have already said, glad to hear your GTG, looking at the BCG has me thinking that I might upgrade to the LMT enhanced carrier when the time comes.
During my talk with 'Gunz, he mentioned that someone had a misfeed that resulted in bullet setback with that same remanufactured ammo and that the crimp looked odd.
IMO, bullet setback during chambering definitely could have caused the extremely high chamber pressure and resultant case failure / KB.
I'm hoping Gunz will grab some of the ammo so I can disect it. I'll be able to get an idea of the neck tension by pulling some down.
Cincinnatus
07-12-13, 08:42
I assume the lower was still operational after this, but was there any damage to it at all?
I assume the lower was still operational after this, but was there any damage to it at all?
IINM, he mentioned the lower was gtg in the other kb thread.
ZINCOGNITO
07-13-13, 19:23
Wow! Now, if I could only find a latest generation LMT E-BCG.....
gesundheit
07-15-13, 02:50
Wow! Now, if I could only find a latest generation LMT E-BCG.....
They are becoming less and less rare. Just keep your eyes peeled as they do become available regularly.
K.L. Davis
07-17-13, 11:05
There's still emotional damages though. :p
And IG has some emotional damage all right!
Scottsdale Gun Club has some now on sale. I am unsure which generation because stuff like that matters not.
Wow! Now, if I could only find a latest generation LMT E-BCG.....
Scottsdale Gun Club has some now on sale. I am unsure which generation because stuff like that matters not.
I see the complete assemblies with bolt and carrier. Do you have a link for just the carrier?
ZINCOGNITO
07-17-13, 15:11
Scottsdale Gun Club has some now on sale. I am unsure which generation because stuff like that matters not.
Thank you sir!
I didn't say anything about carriers. ZINCOGNITO- whom I was replying to asked about the LMT E-BCG. BCG= Bolt Carrier Group- which means a carrier, bolt, firing pin, retaining pin and cam pin.
Had he asked for a carrier, I wouldn't have replied.
I see the complete assemblies with bolt and carrier. Do you have a link for just the carrier?
Do all the LMT enhanced carriers have that tiny weep hole behind the 3 exhaust ports?
Any idea what that's for? Just noticed it the other day on someone's carrier. :confused:
Do all the LMT enhanced carriers have that tiny weep hole behind the 3 exhaust ports?
Any idea what that's for? Just noticed it the other day on someone's carrier. :confused:
The earlier models don't appear to have that hole. Sitting here noodling a standard bolt group, it appears the hole is on the high pressure side of the gas rings when the bolt is locked. Could it be a pre-venting gas to delay unlocking?
The earlier models don't appear to have that hole. Sitting here noodling a standard bolt group, it appears the hole is on the high pressure side of the gas rings when the bolt is locked. Could it be a pre-venting gas to delay unlocking?
It's definitely on the pressure side. I poked a dental pick into it to see if it went all the way in.
This thing could either be brilliant... or complete snake oil.. :confused:
I call it the "bleed" port.
Seems to line up with the fill port under the gas key.
It is A way of reducing gas drive.
What I don't know is if it provides any regulation effect or increased consistency.
General theory implies that the main gas port in the barrel needs to be bigger than normal to compensate for the bleed port.
Or put another way, the bleed port compensates for a larger than normal main port.
I'd love to see that sucker on high speed camera footage.
It's definitely on the pressure side. I poked a dental pick into it to see if it went all the way in.
This thing could either be brilliant... or complete snake oil.. :confused:
I'm leaning towards snake oil. Any changes to the gas system that alter the volume of gas or the time it takes for the bolt group to pressurize are going to render the "enhancements" to be ammunition sensitive. If LMT claimed that the enhancements were made for a specific cartirdge such as M855, the needle on my validity meter might start moving towards the brilliant side. That being said, they may very well be for M855 but admitting it would limit the marketing reach of the enhancements.
I'm leaning towards snake oil.
I am too, but I'm trying to keep an open mind.
I've never really read any manufacturor's info on what this is designed to accomplish. :confused:
I believe that LMT did actually state the purpose of that and I know something was designed to slightly delay unlocking. That being said I know that every person who was shot the LMT enhanced carrier said they can notice the difference.
The earlier models don't appear to have that hole. Sitting here noodling a standard bolt group, it appears the hole is on the high pressure side of the gas rings when the bolt is locked. Could it be a pre-venting gas to delay unlocking?
Sad for the loss. But happy nobody got hurt which probably would have cost more than the damage. What is interesting is the designed safety of the platform.
halfmoonclip
08-02-13, 19:38
Skimmed thru' four pages hoping for some solid speculation as regards WTF happened.
A round pushed deep was one theory; were any of the other rounds fired showing any pressure signs?
Moon
Skimmed thru' four pages hoping for some solid speculation as regards WTF happened.
A round pushed deep was one theory; were any of the other rounds fired showing any pressure signs?
Moon
Just look at the first photo in Post #1, the case failed.
Insert Occam's Razor here...
Mall_Ninja
08-03-13, 00:45
The ammo company SHOULD be replacing the parts, they broke them. That doesnt mean other peoples safety should be risked by not sharing the info on the ammo manufacturer, that borders irresponsibility.
I have a friend of a friend, in Vegas (not far from AZ) who just KB'd his rifle last week on ammo he got from a similar source. To answer someones question about a lesser brand having the same style KB, here are the images of his Bushmaster (Windham manufacture, not a DPMS):
http://i112.photobucket.com/albums/n169/JoeDaddy_05/E7EB19E0-7D86-475B-86D6-25CBA652572E-9279-00000699666E62DC_zps43024240.jpg
http://i112.photobucket.com/albums/n169/JoeDaddy_05/06DA9D97-6F9A-4B7C-9FFA-BA5FB2484FFD-9279-000006996DE58546_zps538633d3.jpg
http://i112.photobucket.com/albums/n169/JoeDaddy_05/B5EC8D64-A17B-46FA-9757-C5276D25BEAE-9279-0000069974B73997_zps8e33e5cf.jpg
http://i112.photobucket.com/albums/n169/JoeDaddy_05/2E63A8BF-92A0-4577-8EE5-806DECBD71F5-9279-000006997CDEC84A_zpsc8c8cb9b.jpg
http://i112.photobucket.com/albums/n169/JoeDaddy_05/950BA8DF-1DA9-4958-8166-321823C45907-9279-00000699846D5CDA_zpsd91139e7.jpg
http://i112.photobucket.com/albums/n169/JoeDaddy_05/IMG958672_zps5b511730.jpg
Only injury was a bloody lip, small cut, not sure which part it was...
halfmoonclip
08-03-13, 05:50
Just look at the first photo in Post #1, the case failed.
Insert Occam's Razor here...
Surely a 'No shit, Sherlock' moment...:D
The question being 'why'? Overcharge? Wrong powder? Round pushed into the case? The infield fly rule? Maybe it was Bush's fault?
There was a metric shit-ton of pressure involved; something had to generate it.
Moon
That doesnt mean other peoples safety should be risked by not sharing the info on the ammo manufacturer, that borders irresponsibility.
Read all of 'Gunz posts, in this thread, carefully, and take that info to google. You'll know what ammo it was in mere seconds.
Surely a 'No shit, Sherlock' moment...:D
The question being 'why'? Overcharge? Wrong powder? Round pushed into the case? The infield fly rule? Maybe it was Bush's fault?
There was a metric shit-ton of pressure involved; something had to generate it.
Moon
Got nothing for you smart ass...
halfmoonclip
08-03-13, 18:56
Got nothing for you smart ass...
Hey, I tried to temper it with a grin, okay?
Besides, nothing is what I got the first time, which is what led to the second question.
But I've no desire to argue about it.
Moon out.
The ammo company SHOULD be replacing the parts, they broke them. That doesnt mean other peoples safety should be risked by not sharing the info on the ammo manufacturer, that borders irresponsibility.
I have a friend of a friend, in Vegas (not far from AZ) who just KB'd his rifle last week on ammo he got from a similar source. To answer someones question about a lesser brand having the same style KB, here are the images of his Bushmaster (Windham manufacture, not a DPMS):
http://i112.photobucket.com/albums/n169/JoeDaddy_05/E7EB19E0-7D86-475B-86D6-25CBA652572E-9279-00000699666E62DC_zps43024240.jpg
http://i112.photobucket.com/albums/n169/JoeDaddy_05/06DA9D97-6F9A-4B7C-9FFA-BA5FB2484FFD-9279-000006996DE58546_zps538633d3.jpg
http://i112.photobucket.com/albums/n169/JoeDaddy_05/B5EC8D64-A17B-46FA-9757-C5276D25BEAE-9279-0000069974B73997_zps8e33e5cf.jpg
http://i112.photobucket.com/albums/n169/JoeDaddy_05/2E63A8BF-92A0-4577-8EE5-806DECBD71F5-9279-000006997CDEC84A_zpsc8c8cb9b.jpg
http://i112.photobucket.com/albums/n169/JoeDaddy_05/950BA8DF-1DA9-4958-8166-321823C45907-9279-00000699846D5CDA_zpsd91139e7.jpg
http://i112.photobucket.com/albums/n169/JoeDaddy_05/IMG958672_zps5b511730.jpg
Only injury was a bloody lip, small cut, not sure which part it was...
That is downright nasty.
Mall_Ninja
08-04-13, 01:33
Agreed, he was very lucky for such a minor injury...
Grand58742
08-04-13, 04:20
The ammo company SHOULD be replacing the parts, they broke them. That doesnt mean other peoples safety should be risked by not sharing the info on the ammo manufacturer, that borders irresponsibility.
I have a friend of a friend, in Vegas (not far from AZ) who just KB'd his rifle last week on ammo he got from a similar source. To answer someones question about a lesser brand having the same style KB, here are the images of his Bushmaster (Windham manufacture, not a DPMS):
Only injury was a bloody lip, small cut, not sure which part it was...
Just another reason I don't trust reloads from an unknown company or ones I don't load myself.
Guy was lucky and hope the company makes it right for him.
Mall_Ninja
08-04-13, 14:09
Just another reason I don't trust reloads from an unknown company or ones I don't load myself.
Guy was lucky and hope the company makes it right for him.
Not sure if you are referring to me or OP but in the case I posted about, if you look at the ammo box pic, you will see they were marked "NEW"...
Grand58742
08-04-13, 16:37
Not sure if you are referring to me or OP but in the case I posted about, if you look at the ammo box pic, you will see they were marked "NEW"...
Yep, you're right. Looked like the "RE-MFG" had a dot in the block and missed the X on the "New" block since I was on my phone.
Either way, relatively unknown company. Not sure if I would trust any company personally that wasn't a brand name when it comes to ammo. While I will give most other items a whirl even if they are unknown (mags, grips, stocks, etc) ammo is not something I will compromise on as it has the greatest potential to cause the most damage. A $20 magazine can be replaced easily if it fails. A $1100 carbine because someone overcharged a round? I'll stick to the big boys.
i am glad no one was hurt ! but ouch ......the looks like a plugged barrel was part of .......by a squib load, next was full load pushing out the bullet but psi goes over the limit !!
Mall_Ninja
08-04-13, 23:51
Either way, relatively unknown company. Not sure if I would trust any company personally that wasn't a brand name when it comes to ammo.
I completely agree, thats why I use this stuff instead of "de-linked" or re-loads:
http://i112.photobucket.com/albums/n169/JoeDaddy_05/IMG_20130804_214107_643_zpse06e9491.jpg
Ammo is not something I will compromise on as it has the greatest potential to cause the most damage. A $20 magazine can be replaced easily if it fails. A $1100 carbine because someone overcharged a round? I'll stick to the big boys.
Again, I completely agree. Now we are just talking about "little" .223/5.56mm rounds. How comfy would you feel using no name/re-loads on a $6000 bull-pup 50 BMG? :D
Thats a big ass BOOM going off right next to your cheek...
Not to mention the responsibility of putting this combo in the hands of someone else. How would you feel if you used something questionable and that choice turned out to hurt or kill someone else?
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