Out Of Battery Detonation AR

[DaveTooley]

Is that even possible?

Oh yes it is.

if the brass is soft from a bad anneal that ejector swage would happen on a normal pressure load.

i take it that no one here is familiar with forging of metal. I have been working in the metal forging business for over 20 years. When any metalis soft it will flow. Especially if the op'er does not know the history of the brass.

I seen it here from a local shooter. He scrounged brass at a local gun range. Every year they burn off the grass. Guess where he got the brass right after they burned the grass. Two weeks later he blows his gun up exactly like this. The brass was annealed dead soft from the fire.

Case heads blow out like this all the time. It just happens. ALL of you guys are assuming that the barrel, bolt, brass, load were all in spec. And if they were this would not happen.

I take it a lot of the guys here are not that familiar with how the AR system works and it shows. I have now given you 3 things that could all leade up to what happened. I don't think he messed up the loading one bit. That 23.5 load is safe for any 556 rifle. 25.3 is max for a 223 cartridge using a 55gr bullet. A 556 can go even higher.

No, case heads don't blow out all the time. Whatever the problem is it happened at the loading bench. 56KPSI would not destroy the bolt, extension, upper and lower.

 

[243winxb]

Seems to be a common problem with AR 223. Doing a mag dump & a squib is not noticed. Some times the brass ejects. Other times the shooter ejects the squib brass, then fires the next round into the bullet left in the barrel. Can be seen on Youtube. 125,000 PSI does real damage.


More KABOOM pnotos

 

[243winxb]

In this Youtube video, the shooter clears the chamber, he thinks. But a bullet is left in the barrel. Hear the sound of the round not firing. Primer pushed bullet into barrel.
Firing into that bullet with the next round, blows the gun up.

 

[writerman]

In addition to pulling the remaining rounds I would look at the 50 that fired for blanked primers that could have locked up firing pin.
Now, that WOULD cause an OOB.

I'm sorry if any of my comments seem to be blaming this on reloaded ammo and not faults with the AR platform, just the way it is.

I just want to know WHAT happened. If it was me, great, don't do THAT again. But it was all the same powder, same bullets, all loaded at the same time. All in one bag, marked H335 23.5 grains, OAL 2.245, 55 grain FMJ. No overpressure signs on any of the fired round, no cratering of primer. PAC brass, CCI primers.

Thanks for the second case picture.
Here's my take on this.

Extension cracked from bolt failure, likely while locked in.
OOB would have done all the damage you had, but bolt would have been blown back. HARD.
Cracked extension indicates (to me) a locked in bolt.
Firing on trigger pull also indicates a locked in bolt.
A cracked bolt head from previous firing could have created a very weak lockup. Bolts do fail.
I think we can eliminate OOB.

Now, on to excessive pressure.
Ejector hole was filled by the brass. That's a lot of pressure. I'm sure that has happened before, I've just never seen that much.
Sometimes I get a few thousandths and have to face off the base a little. To blow that much brass from the base (not thin) into the ejector hole is pressure. Someone give me another reason.

Gas pressure would be much higher with a high pressure discharge, pulling on the case rim with the case locked into the chamber, pulling off the rim, weakened the case base allowing the blowout. I shoot the famous 22 Nosler, and excessive gas causes pulled rims, and smears.

The blowout probably took out the bolt head in the area of the extractor that has no rim support. That is the most likely spot to blow a bolt. That, or adjacent broken lug. Extractor pin broke when extractor blew out. Were all lugs intact with the cracked bolt?

Brass is also suspect. Thin spot in the unsupported area or a thin web. The old Federal thin web issue blew out webs and damaged rifles when reloaded. 0.180" was the web thickness deemed reloadable.

I give you a pass on the actual reloading. I don't know how much of that powder you can cram into a .223 case anyway. How close to compressed is your load?

Bullet push back, from a chamber tightened by carbon, could be a cause of excessive pressure.

Pin in flash hole would have blown primer, reduced flash into powder column. Probably not the case.

If you plan on this NOT happening in the future, DON'T toss out any parts or components. Something may come from a future exam. Impossible with stuff sent to the landfill
Glad all fingers are still intact and functioning.
Best to you in the furure.

Great idea not to toss the components. Here are some more pics. Thanks. Still noodling this. Not out of battery seems logical. But why the bam? Seems to be many possibilities. Starting to eliminate some at least. I fished the parts out of the trash after your suggestion. No broken lugs anywhere, just normal wear. Rifle wasn't that old. Maybe 1000 or so rounds through it. And it was PMC not PAC, my bad. Hard to read the letters at all on the blown round, LOL! I feel blessed I escaped injury, except for one small hole in my right thumb from the bolt catch (extended version) cracking in half and flying back at me, I think that was it. I also clean my rifles completely after each firing, so this one after being cleaned only had the 50 rounds through it. My loads are barely compressed. Since this was the only PMC out of ninety-nine Winchesters, I am beginning to think some sort of case failure? Round was FIRMLY planted within the bolt head. Took a hammer and a piece of oak to get the bolt to draw back. Rim was still on the brass. Thing is, what surprised me was the ejector pin was blown completely out, which seems impossible, but never found it. Would a longer than 1.760 case do that? I've been reading up on case length, and some guy said he regularly shoots 1.800 cases, no problem. My cases are never near that long. 1.765 at most, but I do trim. I trim, clean, and measure but of course could have missed one. Also examined the first fifty round, no overpressure signs at all. Don't believe it was a powder issue at all. Very careful with measuring. I use a RCBS powder measure, set the amount, and always measure at least the first five pulls. I also only shoot a clean rifle, slightly oiled. I try to be careful, but obviously you can't plan for all occurrences. Could have missed one longer one though. Funny how so often the impossible happens. Just play golf, you'll find out fast. Thanks.

 

[writerman]

Here's another pic. of the round.

 

[writerman]

Also, to respond to another comment this was not a mag dump at all. That last round I shot was at least a thirty second wait, because I just happened to be going slowly as I always do when watching targets. All the other shots went 'bang' the way they should, so there was no felt round in the barrel, though many impossibilities could be possible. Still, would like to solve this. I appreciate the feedback so far. It has eliminated some impossibilities.

 

[JerkyFreak]

Is the bullet still in the barrel?

 

[writerman]

c

Is the bullet still in the barrel?

Clear barrel, no damage to barrel at all. No swelling, no marks. It was a 24" ss bull barrel, very solid. Also it wasn't that the 'round' was jammed into the bolt, it was the case. Fast typing, my bad. The back of the case was accordianed into the bolt face. Is it possible that a round could be fired, the recoil felt, the bam just like a normal bam, and the round still not exit the barrel? I find that hard to imagine, though again, the impossible sometimes happens. Seems like according to the damage, that the pressure built up, the round was chambered, and the minute the bolt shot back everything was destroyed. I don't see how a round could exit the barrel, and still build up that much back pressure at the same time.

 

[243winxb]

Is it possible that a round could be fired, the recoil felt, the bam just like a normal bam, and the round (bullet) still not exit the barrel?

Maybe?
Bullet moves out of case at primer firing, because of low neck tension/bullet hold. Powder has not produced much pressure.

The bullet sits in the rifling, acts like a plugged barrel. The pressure spikes when the powder starts building pressure & opens the action. Ejects the empty brass. But gas should be felt in the face or noticed??

Port pressure is around 13,000 PSI. May not take a lot of pressure trapped in the chamber to open tne bolt?

The next round is loaded & fired, into the plugged barrel.

My guess. Most times we dont know wnat happened.

Bullets moving to soom has happened with magnum bolt guns, except the locked action contains enough pressure to push the bullet out the barrel.
An AR action will open and let gas vent back & out the ejection port.

 

[Highpower-FClass]

@writerman do you remember whether you had an issue at all chambering the round that went kaboom? Another poster mentioned the possibility of the bullet having been pushed into the case.

Is it possible you had a misfeed on this round, causing the bullet to be pushed into the case, and the bolt was re-racked and the round chambered without being inspected?

Barrel obstruction or the bullet being pushed almost all the way into the case seems to be the main candidates for the extreme pressure, if it was loaded the same as the others.

 

[boltfluter]

Whatever happened, I am with Dave, the pressure was off the chart! In excess of 100,000 psi plus I would assume. I would be nervous until this is figured out. Sorry, nothing to add.
Paul

 

[writerman]

@writerman do you remember whether you had an issue at all chambering the round that went kaboom? Another poster mentioned the possibility of the bullet having been pushed into the case.

Is it possible you had a misfeed on this round, causing the bullet to be pushed into the case, and the bolt was re-racked and the round chambered without being inspected?

Barrel obstruction or the bullet being pushed almost all the way into the case seems to be the main candidates for the extreme pressure, if it was loaded the same as the others.

Yes, could have been a misfeed, but there was no indication. Bolt shot home, trigger pulled in a slow string of successful shots, last shot sounded fine, no mag dump, everything seemed normal until........it's obvious to me by now it was of course a huge overpressure situation, not caused by load or barrel obstruction previous to this one round being fired. Misfeed is one possible culprit and I'm asking about an overlength case as well? Slightly, nothing huge, maybe 1.750 at best? Some people shoot up to 1.800 which I would never attempt. Cracked barrel extension on the last shot? No pressure signs on any of the previous rounds at all. No cratering, no flattened primers beyond what I usually see in a .223. It was a couple grains below max load recommended. I hate facing dangers that you can't predict or see, but I guess life just throws a few your way at times. This was one of them. This is hard to figure out. Bent the magazine well, two fracture lines of the coating on either side of the outside of the well, warped the magazine well, split the upper, cracked the barrel extention, split the bolt end, destroyed the ejector, ejected the pin holding it in place, blew up the magazine, someone asked about the cam pin, I used the gold Lantac special cam pins, nothing, nothing at all happened to that. No marks, no damage at all. Barrel still looks good, though I am not going to use it again. LOL! My life's worth a whole lot more than two hundred bucks. First time in thousands upon thousands of rounds fired out of AR's over the years, starting in 1973. Sure surprised me. Still looking for your feedback, your theories. Thank you all.

 

[dellet]

Maybe?
Bullet moves out of case at primer firing, because of low neck tension/bullet hold. Powder has not produced much pressure.

The bullet sits in the rifling, acts like a plugged barrel. The pressure spikes when the powder starts building pressure & opens the action. Ejects the empty brass. But gas should be felt in the face or noticed??

Port pressure is around 13,000 PSI. May not take a lot of pressure trapped in the chamber to open tne bolt?

The next round is loaded & fired, into the plugged barrel.

My guess. Most times we dont know wnat happened.

Bullets moving to soom has happened with magnum bolt guns, except the locked action contains enough pressure to push the bullet out the barrel.
An AR action will open and let gas vent back & out the ejection port.

Except the bolt won’t unlock until the bullet passes the gas port. So it’s unlikely that if there was not enough pressure to push the bullet out the barrel, there would be enough pressure to cycle the action.

If the bullet moved an inch down the barrel on primer ignition, then it could very well act like an obstruction when the powder ignited. Think a very worn throat creating creating a very long jump.

For the OP it’s worth checking the barrel. A worn throat should be easy to see with a bore scope, or checking where the bullet hits the lands.
The other thing to check would be for a loose spot with a cleaning rod and a tight patch. Looking for a bulge where the obstruction might have been.

It’s no doubt this was excessive pressure. Running numbers through quickload it’s hard to come up with a way that this powder bullet combination alone could create this much pressure. Considering proof loads are about 75,000 psi, it’s safe to say that was exceeded.

Basically the most likely causes too much powder, not likely without a second factor. Wrong powder. Barrel obstruction, including worn throat example.

Something no one has mentioned, but I alluded to, is that there is no guarantee that this is the only kaboom round. There are at least 49 more to either test fire or brake down and examine. I suggested before to start by simply weighing those rounds.

Still lots of basics to look at. Including the possibility of a long case neck being pinched in the chamber around the bullet.

 

[rockhound78]

Possible very little tension holding the bullet in the case and upon primer ignition, bullet moves into the throat and stops, followed by full powder ignition. Bullets acts as obstruction sending pressures soaring. Pressures reach failure point and bullet exits bore.
Just a thought

 

[Walt Schmidlin]

In this Youtube video, the shooter clears the chamber, he thinks. But a bullet is left in the barrel. Hear the sound of the round not firing. Primer pushed bullet into barrel.
Firing into that bullet with the next round, blows the gun up.

After watching the video I’m very happy I no longer shoot XTC matches

 

[jelenko]

So. What should the OP do next?

Here's what I think we're saying:

Problem originated at the loading bench​

Dissemble the remaining rounds​

Measure length of each case [note: without knowing the length of the chamber, all cases should measure less than 1.760"]​

Confirm the same powder and amount in each.​

Anything else that should be checked?​

​

Going forward - how about the OP listing the steps in his case prep and loading processes? Maybe there's some advice we could provide once?​

 

[dellet]

So. What should the OP do next?

Here's what I think we're saying:

Problem originated at the loading bench​

Dissemble the remaining rounds​

Measure length of each case [note: without knowing the length of the chamber, all cases should measure less than 1.760"]​

Confirm the same powder and amount in each.​

Anything else that should be checked?​

​

Going forward - how about the OP listing the steps in his case prep and loading processes? Maybe there's some advice we could provide once?​

Weigh each round before disassembly
Measure the neck thickness of the blown case, it’s not likely to have changed much, a thick neck now would have only been thicker pre firing.
Check the throat and cartridge jam length
Check for a loose spot in the bore possibly indicating a bulge do to obstruction.

Consider that the one odd headstamp might not even have been the same load and where it might have come from.
For all we know he some how managed to get a 300 blackout round in a 223

Consider all options, don’t be so proud to assume that would never happen to me.

 

[rockhound78]

What CCI primer were you using? Wasn't there an issue with some? Not going off on the first strike, but on the second sometimes, sometimes not at all? Could it have been a wonky primer that didn't ignite the H335 like it should have leading to the bullet stuck in the throat then full ignition? Bullet acted like an obstruction?

 

[writerman]

To all of you, I thank you for your comments and look forward to more. One request, though you can think what you want. On this end, no one is 'too proud' to admit to mistakes. They happen all the time. I am simply trying to figure out WHAT happened, so it doesn't happen again. I am tending toward a linking series of small unfortunate events that added up. It happens all the time. Planes crash because of fifteen linked small events, none of which on their own would have caused the crash. I will do as you say and take apart some rounds and measure powder. I don't see how an RCBS powder machine could make that big of a mistake, when the first five rounds and always weighed and measured. I did to back and measure ALL of the remaining hundred rounds, there were more than I thought, and each one measure slightly under 1.760. I use a precision steel micrometer. My reloading process? First, I clean the brass with steel pins, soap, and dishwashing fluid in a tumbler, so that when I inspect them I can see everything. I then inspect each one, always. Then I anneal every second time or so. Found much less case splitting that way. Then I remove the primer and full length die them. Then I measure them in my Wilson cartridge guage, and select any oversize and trim them. Then I let them dry out from the cleaning, and deburr them, clean out the primer pocket. I only shoot fully cleaned guns, always. Always clean them right after I get home from the range. This rifle was not old, probably a thousand or so rounds through it flawless, one of the best and most accurate barrels I have ever owned, a 24" fluted SS bull barrel. CCI small rifle primer. There was only one strike. Wasn't a blackout cartridge. I don't even know if they would chamber, since they are .300. What I am suspicious on is the random round in the bag. Might have accidentally picked that up without realizing it and therefore cannot account for what powder load was in that particular one. I will, I assure you, ONLY load full bags or boxes that I know the load and specs. on, and NOT throw a random round in there. They are all my reloads however and I am fairly certain that none are close to being max loaded. None. Ever. Just don't do that. There are some more pics. on some other replys. I can only reply 24 times a day, then they lock me out for 24 hours since I am not yet a gold or silver member. Please forgive any delays in responding, they are not my choice. Another point is I always do a light crimp on all my AR cartridges regardless of caliber. I go from one box to throw them into the finish box, so I don't miss any. My greatest concern is that if indeed I did make a mistake somewhere, that I find out just what it was so that it won't happen again. Admitting the mistake is the cake part, no big deal. I just want to know what happened. Thanks again, and your input has been invaluable. This is a wakeup call to be more meticulous in the reloading process and keeping track of what is where and the specs on it. I always label my bags of round with everything, powder, weight, caliber, bullet weight, OAL, time, etc. Everything. More info is that the bolt came back and stopped when it blew up the carrier, digging into the upper, about a quarter inch from the end of the barrel extention. Maybe that means something to those who know more than I do. Thanks again.

 

[dellet]

So here’s a serious question that might actually be the answer.

If you are so meticulous and anal about check and double check, how did you miss the odd headstamp?
Or did you see it and figure, no problem using it?

Yes, 300 blackout will often chamber in a 223/556 chamber. An internet search will bring up thousands of hits.

That may actually be a question worth pursuing. Where did the oddball come from?