Bad day at my range

When I shot my 300 blackout I do not and I repeat I do not even take a 223 or 5.55. chambered anything with me..... I don’t trust myself enough, just because of what happened here.
You can shoot all the 5.56 out of your .300 that you want to. It's the other way round that is the problem.

As I said before, there were no indications I had any ammo for a rifle present outside of 5.56. In fact if it had been the first round in the mag I may have caught it. The fact that that it was chambered at least twice with the setback being what let it be fired makes me think that the real culprit here was the brass catcher. If it had been ejected on the ground I would have been immediately inspecting it. But because it was ejected and then another round fired with no issue, it was forgotten. When I cleaned out the brass catcher, it must've gotten lost and then found it's way into a mag.

What I am changing now: Every round will be inspected at the range before loading into a mag.
If a rifle malfunctions it will immediately be removed from the firing line, inspected, ammo sequestered and then diagnosed later. Nothing that failed to fire will be allow back into a live magazine.
 
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Got my care package from Cincinnati today

16711f6b6f7b9e14f0dc7abc0cedcc79.jpg
 
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Will a 5.56 round fit in a 300 chamber?
Easily. The .224 neck will fit inside the throat of a .300 chamber since it's essentially the same brass (I make .300blk cases from 5.56LC all the time)

But that particular combo wont damage the firearm like vice versa did. In fact I wish that is what happened. I would have ended up with a funky fireformed case and bad accuracy instead of a tiny bomb
 
Easily. The .224 neck will fit inside the throat of a .300 chamber since it's essentially the same brass (I make .300blk cases from 5.56LC all the time)

But that particular combo wont damage the firearm like vice versa did. In fact I wish that is what happened. I would have ended up with a funky fireformed case and bad accuracy instead of a tiny bomb


Will the case behind the shoulder of a 223 case fit into the throat of a 300 chamber? Isn't the 300 case shoulder closer to the base than the 223 making it necessary for the 223 case behind the shoulder and not just the 223 neck to fit into the throat of a 300 chamber. I do not know much about a 300 and am curious.
 
But that particular combo wont damage the firearm like vice versa did. In fact I wish that is what happened. I would have ended up with a funky fireformed case and bad accuracy instead of a tiny bomb
It might not damage the firearm...but it potentially would’ve destroyed a silencer if one was attached. The bore designed for a .30 might’ve saved it, depending on how wonky it got. :eek:
 
I am still a bit confused and curious. The 223 on the right has a diameter of .354 at 1.438 inches from the base. If you go 1.438 inches from the base of a 300 Blackout you are beyond the mouth of the case and into the .308+ portion of the barred since the 300 Blackout case is only 1.368 long. It does not seem as if the .354 portion of the 223 case would fit into the .308+ portion of the 300 barrel. What am I missing here? I do not have a 300 Blackout or else I would just go down stairs and try to get a 223 to chamber in it. I suppose the 300 barrel is not .308 in the leade, but the case at the mouth is still smaller than .354.

300 blackout dimensions.png 223 dimensions.png
 
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I am still a bit confused and curious. The 223 on the right has a diameter of .354 at 1.438 inches from the base. If you go 1.438 inches from the base of a 300 Blackout you are beyond the mouth of the case and into the .308 portion of the barred since the 300 Blackout case is only 1.368 long. It does not seem as if the .354 portion of the 223 case would fit into the .308 portion of the 300 barrel. What am I missing here? I do not have a 300 Blackout or else I would just go down stairs and try to get a 223 to chamber in it.

View attachment 182429 View attachment 182430

I’m sorry, but what exactly are you confused about? .300aac can cause a kaboom if accidentally loaded into a 5.56 chamber........it’s as simple as that, there are MANY documented cases of this happening and I think the OP explained it pretty clearly. Your nuking it with all the math and measurements. Some things really aren’t that complicated.
 
I’m sorry, but what exactly are you confused about? .300aac can cause a kaboom if accidentally loaded into a 5.56 chamber........it’s as simple as that, there are MANY documented cases of this happening and I think the OP explained it pretty clearly. Your nuking it with all the math and measurements. Some things really aren’t that complicated.

You must not understand the question I asked.

It was stated that a 223 would do no great damage if fired in a 300 Blackout chamber. My question is whether a 223 round can fit into a 300 Blackout chamber. The math and measurements seem to suggest that it can not.

The OP was quite clear what happened to his rifle. That, however, is not the source of my confusion.
 
.300BLK uses the same brass cut shorter......depending on bullet profile they will chamber in a NATO 5.56 chamber. Especially the shorter skinny 120s.

This is one of the main reasons I have not considered getting a firearm chambered in 300Blk. I would have thought that the designer of that round would have made it so that it would not chamber in a 223 chamber to avoid such situations. Would it not be possible to have done something like reducing the taper just a bit so it would not fit. It seems like a design flaw to me.

That's what I was going to say, Charlie. Usually, when a cartridge for a particular rifle is developed from a chambering common for that same rifle, something is done to keep the bigger one out of the smaller one.

I'm real surprised that I have never heard that this could happen. Prolly others are hearing it for the first time, too. Good that we know it now! Glad no one was hurt learning about it. Now we need to stay alert for it.

Reminds me of the short, simple advice for life from Captain Disko Troop, aboard the fishing vessel We're Here (Captain's Courageous, by Rudyard Kipling).
He said, "You got to keep things separate."
 
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So to rebuild the Kaboominator I ordered a new Aero Precision assembled Upper with the new Faxon barrel to match a new Aero lower (old one was fine just used it for another upper) that I was intending on using previously to the Kaboom event. I also got a Toolcraft non-logo BCG. I will reuse the existing rail, barrel nut, gas tube and low profile gas block (gas from the kaboom never entered the gas system) but I repinned those.
A Rise Armament RA140 flat blade trigger and an H buffer is about the only thing fancy in that lower along with an MFT minimalist stock. This is my deer hunting and woods AR so I'm trying to keep it light. Optic will be the Leupold American Marksman aka VX1 with Windplex reticle on the ADM recon mount.

Hope I get it assembled on this long weekend. Maybe I will dub this one the Richmond rifle [emoji854]
 
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Charly asked. if a 223 will chamber all the way in a 300B/O barrel. I had a 300 B/O barrel laying around so I tried to drop a 223 round in and it would not go. Sorry for the poor pic quality but it shows a 300 B/O and a 223 Rem in a 300 B/O barrel
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Charly asked. if a 223 will chamber all the way in a 300B/O barrel. I had a 300 B/O barrel laying around so I tried to drop a 223 round in and it would not go. Sorry for the poor pic quality but it shows a 300 B/O and a 223 Rem in a 300 B/O barrel
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in a plunk test, a .300blk round wont fit in most 5.56 chambers either, until you slam the bolt home a few times or use the FA
 
in a plunk test, a .300blk round wont fit in most 5.56 chambers either, until you slam the bolt home a few times or use the FA
Will the BO fit in the Wylde chamber?
 
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Got this email today:

From: Faxon Firearms <[email protected]>
Sent: Monday, January 6, 2020 1:58 PM
To: somejackass@someaddress
Cc: [email protected]
Subject: Re: Thanks for making a strong product


Hi ikarus1,


Thank you for taking the time to contact us! We're glad to hear no one was hurt and those are some pretty amazing pictures! I would certainly hang on to that slug as it is pretty unique. I've never seen one outside of a cross-section. At this point, we won't need the barrel back, but, we'd like to send out a replacement barrel for you as well as some swag, both as a thank you for sharing with us and to help off-set the cost of building up a new rifle (or at least upper half).


If you let me know your preferred shipping address I can get it shipped out right away! Also, what size T-shirt do you and your son wear?


Thanks,

Martin

Customer Service

Faxon Firearms

On Thu, 2 Jan at 3:21 PM , snipped wrote:

Hello,


I wanted to tell you guys that your Gunner profile 18” 5.56 NATO barrel is probably the strongest barrel in it’s class. We inadvertently tested it at well past it’s proof pressure yesterday…..


I built a 5.56 NATO upper about 2 years ago that quickly became my favorite with it’s easy recoil due to rifle gas system and excellent accuracy. I didn’t skimp on the barrel or bolt because that is the heart of an AR.


Yesterday, on New Years Day, my family and I experienced an incident where my 15 year old son was the shooter firing the last magazine that we had at our outdoor backyard range.

He had fired approximately 100rds thru it during this time, but on the last round he experienced a catastrophic failure. The explosion sent gas thru the empty GI steel mag and blew out the floorplate.

The upper bulged, the bolt was locked into battery and the upper actually cracked. Stress fractures all along the top of the receiver where the optic mount was. The dust cover was bowed out and the bolt catch was broken.

When we separated the 2 rifle halves, we noticed that the bottom of the 9310 steel BCG cracked at the bolt gas vents, and it blew out the roll pin at the gas block (also a Faxon product).

However, the actual Faxon .625 lo-pro gas block and nitride tube seemed to be fine.


We knew it had to be a barrel obstruction, so I decided that since the upper was wrecked I had to find the cause ASAP. I probably should have sent it to you guys because I may have been able to salvage more.


Upon further inspection we discovered that a lone .300BLK round had somehow found it’s way into one of my 5.56 magazines, and it had chambered and fired.

Thankfully, there were no injuries to my young son, and I attribute this to the quality and strength inherent in your product as well as a strong Stoner rifle design and the HPT/MPI bolt from Alpha.


This could have been the worst day of my life as a parent, but when I did an inspection (with an angle grinder!) we found the 120 grain HPBT bullet had swaged down perfectly from .308 to .224.

This will probably become a very expensive piece of copper jewelry for me as a reminder. It had made it 4 inches past the chamber throat into the barrel and there was no sign of a BULGE in the barrel.


That is a strong product and it helped keep my son safe and intact. Thank you so much for making a quality product. Thank you many times over and I hope 2020 is a great year for your company.


This was 100% my error but if this helps someone in the future I will be happy to be a testimonial for your company! If you are interested in inspecting the barrel I will be happy to send it your way.


Thanks again,


ikarus1

@Ikarus1 wanted to share this with you. Today I met Mr Bob Faxon at ShotShow. Mr Faxon was really a genuine stand up man (so was the rest of his people with him). I told him about reading your story on the forum and how much the strength of their product and customer service influenced my purchase of a 9mm barrel for my next pistol build. We talked for a long time and covered many topics. It is good to know there are still some great American manufactures that value their customers.


Sent from my iPhone using Tapatalk
 
@Ikarus1 wanted to share this with you. Today I met Mr Bob Faxon at ShotShow. Mr Faxon was really a genuine stand up man (so was the rest of his people with him). I told him about reading your story on the forum and how much the strength of their product and customer service influenced my purchase of a 9mm barrel for my next pistol build. We talked for a long time and covered many topics. It is good to know there are still some great American manufactures that value their customers.


Sent from my iPhone using Tapatalk

Wow. Thanks man that just made my night. BTW I sighted in the new rifle and it only took 6 shots and about 40 clicks up (10MOA) and 10 (2.5MOA) over to start cutting cloverleafs at 75yds from just a cheap caldwell front rest. I think I'm gonna like the upgrades.
Pretty sweet shooter and all the tragedy ended in triumph just like every good ending!
 
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The smart thing to do is never own two AR rifles that take the same case. 5.56 and 7.62 should do just fine for anything out there. Sometimes I think Murphy lives at my house. And this is just the thing he would do. :rolleyes:
 
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The smart thing to do is never own two AR rifles that take the same case. 5.56 and 7.62 should do just fine for anything out there. Sometimes I think Murphy lives at my house. And this is just the thing he would do. :rolleyes:
Or 5.56 and 45/70.
One won't fit into the mag.
The other will fall though the barrel and drop on the ground.
 
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