-
Having trouble using the site?
Contact support
AR-15 blew up! Thoughts?
- Thread starter 79steeler
- Start date
No it was Remington .223 ammo, you can see it on the case head and thats what was in rest of magazine also. It was the only ammo he had with him.
That's not nearly enough pressure difference to have a full blown kaboom. It was either charged well past 5.56 pressure levels or the case head was faulty.
Could have been as simple as a defective heat treat on the brass and the entire case got annealed, not just the neck.
Some seem to think Remington is to blame.
Could be, I haven't had that kind of problem with them, but there is history that says they could be at fault.
An annealer that stalled on the line, or a charge density over 100%, or some other slip in quality control could be the cause.
Most factory rounds I've pulled down are 90% or more charge density. Probably a goal for a commercial load.
Could be, I haven't had that kind of problem with them, but there is history that says they could be at fault.
An annealer that stalled on the line, or a charge density over 100%, or some other slip in quality control could be the cause.
Most factory rounds I've pulled down are 90% or more charge density. Probably a goal for a commercial load.
I think the same thing with the threads about my new rifle won't feed, or the bolt won't stay open after the last round.
If you don't know what you are doing, or what went wrong, keep shooting.
Lighning doesn't strike twice in the same place.
Just kidding.
If you don't know what you are doing, or what went wrong, keep shooting.
Lighning doesn't strike twice in the same place.
Just kidding.
Ive shot a couple thousand rounds of this Remington ammo myself with no problems. Must be a one in a million thing?????
That was an extreme pressure round- to make brass to flow like it did into the ejector pocket like that takes gross overpressure.
If it was mine, I'd trash the bolt and barrel extension, and thereby the barrel- pressures were WAY above proof load level, and it's likely that there are stress cracks in both.
I was a weapons guy in a specops unit, so I saw plenty of failures in many different systems. It's hard to say what caused this pressure without seeing parts, but in the military this type of failure would condemn the entire lot of ammo.
It didn't happen in this case, but when an AR fires out of battery the bolt assembly usually blows back with so much force that it will be stuck in the buffer tube, because it will bend the rear end of the lower down from the impact and jam up. The receivers bulge around the chamber opening. On GI aluminum mags the floorplate blows out followed by the spring/ follower/ rounds. Sometimes it'll even blow the hanguards off. It's a quick way to total the rifle. Makes quite a fireball at night, too.
I'd also talk to Remington about the ammo. Maybe they'd exchange it, particularly if they know that it's a bad lot. Don't bother asking them if they've had reports of other problems. That's my 2 cents worth, anyway.
If it was mine, I'd trash the bolt and barrel extension, and thereby the barrel- pressures were WAY above proof load level, and it's likely that there are stress cracks in both.
I was a weapons guy in a specops unit, so I saw plenty of failures in many different systems. It's hard to say what caused this pressure without seeing parts, but in the military this type of failure would condemn the entire lot of ammo.
It didn't happen in this case, but when an AR fires out of battery the bolt assembly usually blows back with so much force that it will be stuck in the buffer tube, because it will bend the rear end of the lower down from the impact and jam up. The receivers bulge around the chamber opening. On GI aluminum mags the floorplate blows out followed by the spring/ follower/ rounds. Sometimes it'll even blow the hanguards off. It's a quick way to total the rifle. Makes quite a fireball at night, too.
I'd also talk to Remington about the ammo. Maybe they'd exchange it, particularly if they know that it's a bad lot. Don't bother asking them if they've had reports of other problems. That's my 2 cents worth, anyway.
Yes, cases do fail. I suspect this is the most likely cause. From what I've read so far I know they were firing .223 Rem ammo but I still don't know what brand of ammo. Was it Remington, Winchester or Federal ammo? Maybe the cheapest ammo available at "bullets r' us"...
It is pretty difficult to double charge a .223 Rem/5.56 NATO case. Case volume of .223/5.56 is about 28.5 ml of H2O. A double charge of 25 grains overflows the case. Compressed loads are about 26-28 gr of powder (Yes, powder density does vary).
Std chamber pressure is 55,000 to 62,000 psi but tested to 77,000 psi (125%) so the chamber should have held up.
Finally, I've had issues with factory ammo and contacted them. I sent them the rest of the ammo for testing and they replaced it. I don't know if they will help out with damage to the rifle, but you can always ask.
FWIW... that area is a "weaker" point at the bolt face, so it only figures that it would blow out there.
I suggest running a tight fitting bore brush or patch down the bore... feeling for a bulged area. Doing so will help understand what may have happened.
Basically, more info is needed.
Remington Green Box 55gr has tended to be a fairly "low pressure / velocity" load.
I didn't notice was the specific 223 ammo mentioned ? ...55gr FMJ, UMC , Freedom bucket ...etc ?
Yes, most likely the brass "flowed" to fill the recess in the bolt face- to the point where you can see where the brass smeared onto the surface and pushed into the ejector hole. Where the extractor cut lies, it simply blew the spring loaded extractor out of its way and blew out into the barrel extension. Probably over 80,000 psi, as I recall, where case brass liquifies.
Might just be the pictures but it looks like it blew the web out into the extraction groove all the way around.
This was the point of Remingtons "3 rings of steel" safety feature on the 700 action. Full enclosure of the case head, in theory preventing this.
Good idea, but it necessitated that ever controversial extractor. Also, it's more of a talking point than anything- even on a .308 bolt the steel around the extractor groove is only about .035 thick, off the top of my head. I have a Remington bolt in my shop right now where about 2/3 of that rim has blown off, on a 7MM/08.
When I machine barrels for Rem 700 type actions I cut the recess for that part of the bolt with less than .005 clearance radially, so that it has nowhere to go. Factory barrels have lots of clearance in that area.
Good idea, but it necessitated that ever controversial extractor. Also, it's more of a talking point than anything- even on a .308 bolt the steel around the extractor groove is only about .035 thick, off the top of my head. I have a Remington bolt in my shop right now where about 2/3 of that rim has blown off, on a 7MM/08.
When I machine barrels for Rem 700 type actions I cut the recess for that part of the bolt with less than .005 clearance radially, so that it has nowhere to go. Factory barrels have lots of clearance in that area.
I had a few boxes of 223 Remington branded ammo that had serious pressure issues in my tikka 223. I was getting split cases and blown primers. I fired 3 rounds and tossed the 5 boxes I had. Not worth taking any chances......
Last edited:
" P-mag still seems functional "
Yea - like a car with the windshield missing...it may function, but isn't safe or recommended.
Seriously, I was searching for 'catastrophic AR failures' and came across this - on July 27th, 2020 I was at a range where the man two positions to my right had a catastrophic failure. He was firing a SBR AR-15 (with an extremely obnoxious muzzle device which send shock waves five shooting positions either side of him) and had his magazine blow out, sending pieces of plastic and unfired rounds in every direction. Fortunately he was uninjured, just shaken.
The Range Safety Officer immediately shut down the range and checked the firearm. I overheard the conversation between the RSO and shooter and supposedly the the BCG was partially open (perhaps 6mm), but the BCG was locked-up and wouldn't move further. There RSO said he didn't see any indication of barrel bulging and the magwell was intact. I didn't take a closer look, but could see 'smoke' coming out of the action indicating the chamber was exposed. I don't know if he was firing when this took place or it occurred as he released the BCG.
Needless to say that was the end of the shooter's range time and he left soon after. Thinking back I can't recall if the report was louder than normal because his muzzle brake was so darned loud. Later when we were collecting our brass we found a blown case and primer near where he was shooting, but if it came from him if would have been a previously fired round and I didn't look at the head stamp - I also didn't ask if he was shooting factory loads or reloaded ammunition..
My 17 year-old grandson and I just built a .223 Wylde AR-15 with a 20" heavy barrel and a 3-9x40 Sig Sauer scope in June, 2020 and we were SO meticulous in our build since it was the first for both of us - we checked head space with 'GO/NO-GO' gauges and made sure everything was OK - it shoots fine and is accurate (better than I am), so our care paid off.
This is at 100 yards - still have some tweaking to do on the scope.
Yea - like a car with the windshield missing...it may function, but isn't safe or recommended.
Seriously, I was searching for 'catastrophic AR failures' and came across this - on July 27th, 2020 I was at a range where the man two positions to my right had a catastrophic failure. He was firing a SBR AR-15 (with an extremely obnoxious muzzle device which send shock waves five shooting positions either side of him) and had his magazine blow out, sending pieces of plastic and unfired rounds in every direction. Fortunately he was uninjured, just shaken.
The Range Safety Officer immediately shut down the range and checked the firearm. I overheard the conversation between the RSO and shooter and supposedly the the BCG was partially open (perhaps 6mm), but the BCG was locked-up and wouldn't move further. There RSO said he didn't see any indication of barrel bulging and the magwell was intact. I didn't take a closer look, but could see 'smoke' coming out of the action indicating the chamber was exposed. I don't know if he was firing when this took place or it occurred as he released the BCG.
Needless to say that was the end of the shooter's range time and he left soon after. Thinking back I can't recall if the report was louder than normal because his muzzle brake was so darned loud. Later when we were collecting our brass we found a blown case and primer near where he was shooting, but if it came from him if would have been a previously fired round and I didn't look at the head stamp - I also didn't ask if he was shooting factory loads or reloaded ammunition..
My 17 year-old grandson and I just built a .223 Wylde AR-15 with a 20" heavy barrel and a 3-9x40 Sig Sauer scope in June, 2020 and we were SO meticulous in our build since it was the first for both of us - we checked head space with 'GO/NO-GO' gauges and made sure everything was OK - it shoots fine and is accurate (better than I am), so our care paid off.
This is at 100 yards - still have some tweaking to do on the scope.
Attachments
The barrel was over chamfered, as seem in this pic, where the case failure follows the deep chamfer on the barrel. The chamfer should be very slight, not countersunk like that one. There is no support at the sidewall of the case. I would guess the other brass has expended in that area, that case was the weaker of the group, but bound to be an issue. This is an issue with the barrel manufacturer. Red arrow shows the area in question, the seond image with a green arrow shows how it should look.
That would do it, especially with cases that didn’t have a lot of ‘meat’ at the head.
I read above that the OP was shooting Remington .223 ammo. This takes me back a long time, but I remember lots of debates on the differences between .223 Rem and 5.56 NATO. And while I don’t remember the Outcome of those debates, I do remember an admonition that they are not completely interchangeable.
Could that be a factor as well?
Sirhr
