Home Forums Hunting & Shooting AR and Tactical Rifles Had a "boom" yesterday

Known good rifle.

Blew the magazine out the bottom, blew the mag bottom off. Bolt hard stuck, case is still in there. See pictures.

223 rifle shooting reloads with 55 Hornady SP over 24.7 grains of TAC. Range brass (which might be the problem?), CCI 450s

Barrel does not seem bulged (as in obstruction), and it would be hard to fit too much TAC in a 223 case, especially under a 55 grain bullet.

Barreled upper is sitting at the 'smith's now waiting for him to have a look.

Thoughts on cause? Thoughts on breaking the rifle down to do forensics?

I run 27 grains of TAC with a 55 grain bullet, no way to get too much powder without noticing.

I figure case is at fault. Probably separated.

Separated case or previous round had 0.0 grains of TAC? Glad you’re ok.

It was the first shot in that series, so I doubt a misfire or barrel blockage.

But, I'm getting the habit of checking the bore prior to shooting from now on.

Range brass is my first thought. Coupla years ago a notorious scrounger at my IWLA range totaled his upper with a reloaded pickup case. He even fessed up about the likely cause.

Schitt happens, but happens less to the prudent. Let us know what he says.

Glad you were not injured. Hardware can be replaced.

I had two pieces of range brass split upon firing a couple of years ago, but I never even knew there was a problem until I examined the brass later. It fired and ejected fine. I guess I got lucky.

Range brass is perfectly fine, if you know what you are picking up. Some is garbage and just stays in the dirt. The last time I picked up any, it was primo new once fired chidt. FC and PMC. That was a few years ago and that's mostly all I've been using since then. I think I picked up 1200 pcs of FC and 600 pcs of PMC. I made it a point to shoot the FC range pick up brass in the black rifle challenge here. If you don't know what you are picking up, leave it lay. Sometimes there's a reason it's laying there. Secondly, I'm wondering if the rifle fired out of battery? Glad to hear no one was hurt as well.

I'd also suspect an out of battery ignition.
I've had two case separations involving range brass over the years, neither caused any damage.
I didn't even know anything was wrong until the front half of the case didn't eject.
If everything is contained in a locked chamber that shouldn't have happened.

Firing pin won’t reach the primer until bolt turns and locks into receiver extension.

That is taking his word that it was a known good gun. Also assuming it wasn’t a high primer. David just doesn’t seem like the guy that would miss that.

Also going by all the ka-booms I’ve kept up with over the years they mostly have been ammo related.

Also gonna say this again, FC is the last brass I’ll ever pick up and it’s the only brass I’ve lost primers in.

Brass laying on the ground needs to be checked for signs of separation no matter the head stamp.

We’re reloaders and range brass is free but the prep isn’t.

Hang fire?

I've had 2 case head separations, in bolt rifles. I didn't know it until I extracted only the back end of the case. Not sure if being in an AR makes a difference or not.

I'm curious to hear what the smith finds.

Glad you walked away unscathed, David

Just a possibility,

Oncce upon a time I was trying to call coyotes. No luck and no luck and no luck.

After about 6 stands, unloading and loading every time with an ar-15, same shell every time, The last time I unloaded I found the bullet setback into the case enough that the bullet ogive was almost into the case shoulder, almost rattling in the case.

I never shot that one but often thought that it could have been a catastrophic event. No way we'll ever know but it would have been hard to diagnose for me.

Now I crimp my 223 better.

I've seen split cases, separated cases, blown primers and set back bullets in AR platforms. Only time I ever saw any damage similar to this was from a slam fire / out of battery condition (not counting the pictures of the 300 BO fired in a 5.56 chambered rifle).

I'm trying to figure out how you can get a slam fire/out of battery when the firing pin can't reach the primer until the bolt rotates and locks into the lugs of the RE?

A bullet setback could cause the bolt to unlock and force the gas/pressure out the easiest route but an OOB firing is next to impossible unless the firing pin is out of spec or broken.

Slam fires have occurred but never resulting in a blown up AR like this.

Not trying to argue just simply going over facts trying to determine what happened.

He was using FC brass?

You can try to figure it out all you want. Over the years, we've all probably had split cases. Never having it fu ck up the gun like this. Something was not right with the load or rifle. A lot of speculation on your end though.. The one sure thing you said is we all need to be very aware of the brass we pick up. Like I said, if its garbage brass, don't pick it up. I find all kinds of military crap brass and leave it lay. I've walked over tons of it. Check out some of the recent manufacture WW brass that they load for the military. Its garbage. The FC I picked up has scamp markings on it, but its commercial brass. Its much better than regular ol FC brass.

Not knowing all the facts, it could have been a high primer that detonated on the closing of the bolt, if there was an obstruction it would have to be past the gas ports otherwise the barrel would have burst since the rotarary bolt would or should have been totally engaged

most people like me, leave bad brass on the range for people that are scavengers for brass to sell for scrap. I only use my brass and in 50 years of reloading never had a problem, or blew up a firearm... you pick up junk and your reloads are junk, stop that ....

most people like me, leave bad brass on the range for people that are scavengers for brass to sell for scrap. I only use my brass and in 50 years of reloading never had a problem, or blew up a firearm... you pick up junk and your reloads are junk, stop that ....

Did not fire on bolt closing, fired with the trigger pull.

No sign of brass not seated properly, but I wasn't really looking for that, as I assumed it would not fire out of battery.

Maybe a bad assumption?

Still waiting for the gunsmith to call me back.

"Bolt stuck hard" means wouldn't cycle at all by hand?

"You can try to figure it out all you want" I thought this was what forums were for?

"Something was not right with the load or rifle" Seriously?

"A lot of speculation on your end though.." Just the facts mam, just the facts. Yes it's mostly a guessing game but as I stated, in all the Ka-booms I've followed, the ammo was the culprit. The design prevents the gun from firing out of battery, yet it's always an answer that comes up and it needs to stop. This gun picked up and seated the cartridge in the chamber, fired after he pulled the trigger, went boom and the pressure went the wrong way. How am I speculating?

I’ve never crimped my .233/5.56 ammo and never had a problem…however…about 15 years ago my local Walmart hadn’t been having much luck moving Remington.233 ammo loaded with 50 grain HP’s. Finally, they marked it down to $5.00/box and I took all they had at that price, for the brass if nothing else. Figured I’d shoot it up for fun… To get an idea of how accurate the stuff was, (it wasn’t btw) I tried it in my Les Baer Super Varmint. After four or five shots, for some reason I ejected an unfired case and did a double take: the bullet was crammed significantly into the case neck, enough so to scare the hell out of me. I shot up the rest of them in a bolt gun. I have never had a problem with any other ammo that way (and still don’t crimp stuff for my AR’s. I suspect that some bullet profiles and some feed ramp configurations don’t play well together.

Sure, but I would rather buy brass than spend the time sorting, checking for incipient separations, etc. Before the crunch, I bought 750 new LC cases for $45 per 250, a bargain IMO. I did buy some once-fired surplus .308 during a previous dearth, which was fine, and only required sorting, sizing and decrimping, but still more trouble than I prefer. I do pick up a few to use for setting up dies, dummy rounds, etc. To each his own.

Have you broke down any of your remaining ammo from that session, to see if anything looks weird (undercharges, overcharges, powder looking different than normal Tac, etc)?

I have. Nothing seemed out of the ordinary.

Glad you're ok!!

i had a boom . had to get a new upper and a mag . it looked as though it went off out of battery

Gunsmith will break it down next week, he’s deer hunting now.

He thinks only the bolt will need replaced.

I’ll update when I know more.

The importance of checking the web area of all fired cases with a wire clip before loading up.
Takes a second & if you feel anything throw the case.

It was an unsupported case, probably just a little out of battery and a little more than “once fired “

Glad you found the suspected cause.

If you get pressure from more known safe rounds so to speak I'd look hard for a carbon ring. They can sneak up on you and create havoc until removed. Normally by scrubbing with abrasive...

Haven't seen the campfire for a long time. Unfortunately it seems that the amount of dumbazzes is spreading.

Hope all else is well with you!

Jeff

Thanks Jeff!

I'll check that out and report back.

No offense intended, but I don't buy the "little out if battery" story. I'll believe it if you can explain it, but otherwise it is doo-doo.

What’s to explain? Unknown brass failure, probably sizing out of spec (someone else loaded these)

We still don’t have it apart. It’s soaking in Kroil.

You can’t get enough TAC in a 223 case to cause a blowup, or at least I can’t. You certainly can’t double charge it.

It was Hornady’s top load of 24.7 TAC under a 55 grain SP with a CCI41 primer, seated to the cannelur.

What’s not to believe?

What alternative are you proposing?

Maybe they can explain it better than I did.
https://www.thehighroad.org/index.php?threads/can-an-ar-15-fire-out-of-battery.408683/
And if your smith hasn’t even got it apart yet, how does he know what happened?

Its speculation at this part.

So, finally got the unit apart, and it was a case head separation. The upper, barrel and BCG are OK, the bolt needs replaced, and the charging handle is bent from me "mortaring" it to get the stuck case out.

No more reloads from pick up brass, I guess.

And no more reloads from friends.

I'm not sure about the logic of the statements in bold above - seems like you're over reacting a bit.

I can't tell from the photo, but what happened to the bolt?

I wouldn't touch brass I didn't know the history of and I wouldn't shoot someone else's reloads, period.

I would have to know the reloader and have solid trust that they knew what they were doing before shooting their reloads, and even then I would probably want to shoot them in their gun, not one of mine.

Range brass? No problem, gimme.

Bolt survived fine, except the extractor is toast.

So it’s range brass reloaded and since there’s no proof of times fired we really can’t lay blame on the manufacturer. But just out of curiosity what did the head stamp read? May be part of a puzzle for someone else.

I doubt it was the brass.

MM

Just wondering
I have seen times when dropping powder that a little would "bridge" or get stuck for what ever reason in the powder dispenser. Wondering if something like that happened and you got a round that may have had a partial charge and this round that got a full charge plus what ever did not "drop" from the other charge?
Just a thought. No matter what happened, sorry it did

Unless it was a range pickup of commercial federal brass, i.e. what you find in American Eagle ammo. That stuff is way to soft, so I could see that being the root cause.

By no means am I the senior hand loader here. But the only brass I’ve had issues with has been Federal; .270 Win and 7mm RM. Some of each, once fired, had primer pockets that wouldn’t hold a primer. On the other hand I’ve loaded Federal 9mm and .40 with no issues. But it’s be hard to get me too go with Federal on rifle ammo again.

"...probably just a little out of battery ..."

How far out of battery does it have to be for an AR not to fire?

I'll stick with hang fire.

Soft brass, such as to allow primer pockets to expand is sure as hell not going to cause a failure like that.

That is high pressure & the brass would have had to have had numerous firings on it to have weakened to that level.

If an AR bolt is even a little out of battery, the FP cannot reach the primer, so I really doubt that the gun fired out of battery either.

Too much powder is far & away the most likely culprit, but as in most post mortems like this, we'll never really know, so pick your theory & stick to it.

MM

Went to the range today and shot 50 rounds through this upper and barrel with only a new bolt, once it was put back together.

Ran fine.

I'm currently of the overgharge theory.

I’m leaning towards a loose neck and bullet setback creating over pressure. Far more damage done to the base than what I can see as just case separation.

But who knows.

Did you miss the part where he bent the charging handle "mortaring" it out? A lot of that damage was post-mortem.

Might be a good idea to bend a paper clip in a short "L"shape to check your brass.

I run the check for separation on all of the brass i use and load for others.

Have you ever seen one mortared that pulled off more than the rim? I haven’t. What took out the pie slice shaped divot was not the extractor. In my mind it took the easiest route and gas escaped through the portion of the rim least supported, the extractor cut.

Mortaring the rifle yielded nothing but a ruined charging handle from me banging it on a table when mortaring didn’t work.

Soaking in Kroil for two days and tapping the back of the BCG with a punch freed up the stuck case.

I wasn’t there when the smith got it apart, but the rim was still partially on the case, he said. He removed that and used a threaded tool (like the one for cases stick in a die?) to get the case out of the barrel.

Sorry the way I read this was you bent the CH mortaring it to get the stuck case out. I didn’t see anything else stating the smith got it out.

So now I’m back to just “I’m glad it worked out”.

What brand brass?

I wonder about his powder measure consistency. He's running a progressive, so I don't know if you can check every case before it gets a bullet seated? Another reason I use a single stage. I always look in the case, just as a double check to CYA... I was going to suggest him pulling the others apart and check to see how consistent his cases are getting charged... I'd do it, just to know for sure..

Don’t recall and I already threw it away. It was mixed range brass.

That is not a case head separation. That separated IN the casehead, not where the casehead joins the case body.