I was asked a question today. Have I ever seen a rifle abnormality/catastrophe by a 5.56 round fired in a .223 chamber. I have not and I have personally fired many, many 5.56 rounds in a .223 without issue. Of course all the "experts" say it is unsafe to do so. But the question was if I had ever seen such a catastrophe and I have not. I now pose the question to you. Have you personally seen, not anecdotally heard of, such a catastrophe? The arguments pro or con is not the issue, just whether any of you have personally seen such occur.
5.56 vs. .223 ----- again
- Thread starter jpjulian
- Start date
VA_XTC_Shooter
Silver $$ Contributor
No I haven't and believe it is a myth based on misunderstanding of the way pressure tests are conducted.
Gavin at Ultimate Reloader has put together the best explanation that I have seen. With pressures actually pretty much the same, the issue is freebore. When you look at most ammo, this isnt an issue because 5.56 bullets are not different thant .223. BUT, as Gavin highlights, there are some bullets loaded for 5.56 that could be problematic due to the bullet profile - tracer rounds.
So what it really boils down to is not 223 vs 556, but rather bullet choice and freebore needed.
ultimatereloader.com
Edit - I do think the chamber dimensions would increase pressure, but how much, I dont know.
Gavin at Ultimate Reloader has put together the best explanation that I have seen. With pressures actually pretty much the same, the issue is freebore. When you look at most ammo, this isnt an issue because 5.56 bullets are not different thant .223. BUT, as Gavin highlights, there are some bullets loaded for 5.56 that could be problematic due to the bullet profile - tracer rounds.
So what it really boils down to is not 223 vs 556, but rather bullet choice and freebore needed.
223 -vs- 5.56: FACTS and MYTHS – Ultimate Reloader
ultimatereloader.com
Edit - I do think the chamber dimensions would increase pressure, but how much, I dont know.
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jelenko
Gold $$ Contributor
Well, in that case, '556' is just another 223 chamber and the whole discussion goes away.No I haven't and believe it is a myth based on misunderstanding of the way pressure tests are conducted.
Gavin at Ultimate Reloader has put together the best explanation that I have seen. With pressures actually pretty much the same, the issue is freebore. When you look at most ammo, this isnt an issue because 5.56 bullets are not different thant .223. BUT, as Gavin highlights, there are some bullets loaded for 5.56 that could be problematic due to the bullet profile - tracer rounds.
So what it really boils down to is not 223 vs 556, but rather bullet choice and freebore needed.
223 -vs- 5.56: FACTS and MYTHS – Ultimate Reloader
The 'myth' is based on the NATO 556 and the SAAMI 223 chambers. Clearly, there are mag length loads that are safe in '556' and not safe in a SAAMI 223 chamber.
I had a guy ask me the other day if I reloaded to 223 specs or to 5.56. I told him that I suppose I load to 223, but just reload to find the right accurate load. Never really thought about it being one or the other.
This would be the OP's question if I am not mistaken. Since I have never seen the load that you suggest, I would disagree your statement, but that being said, as hand loaders, we can create all sorts of unsafe situations.
jelenko
Gold $$ Contributor
Hmm. I haven't seen one either => I am not so sure about some 556 loads blowing up SAAMI 223 chambers.
I did just do a google search and couldn't find one example of 556 ammo even damaging a rifle with a SAAMI 223 chamber.
Not specifically a 223/556 but on a 308, where even starting loads were too hot..yes. Speeds were abnormally high and had all the classic signs of a very high pressure load. I've seen similar more than once but this time stands out as it was pretty extreme. There's a number of reasons why we should not start at max loads, etc. Same for 5.56 in a 223. Most of the time, you'll never have a problem but in that fairly rare situation where even a relatively mild book load is not what you expect, actually happens in your particular rifle...That's when you will apreciate doing things by the book as opposed to what we might assume to be safe because it has always been fine in multiple other rifles. Using 5.56 ammo in a 223 is like starting out with max or above max 223 loads and expecting all to go fine. Odds are, it will but when it doesn't go as planned, the cost can be rather high.
Not once have I ever heard of an issue other than internet geniuses saying it's not safe.
As prolific as the 5.56 and .223 are, if it was really a problem worth noting, it would be known. As many times as people have fired 5.56 ammo in a .223 chamber, whether knowingly or because they didn't know any better...if it was dangerous we'd all have heard of an incident.
As prolific as the 5.56 and .223 are, if it was really a problem worth noting, it would be known. As many times as people have fired 5.56 ammo in a .223 chamber, whether knowingly or because they didn't know any better...if it was dangerous we'd all have heard of an incident.
I'm aware of the theoreticals. That wasn't the question. I was asked if I have ever seen a catastrophic event when a 5.56 round was fired in a .223. I have not and don't think I have ever heard of it happening. My question is if anyone here, in this vast group, has personally seen such an event occur. Thanks for your remarks, but again, I don't want to have another discussion on the pros and cons, just personal observations if someone has actually seen or witnessed such an event.
Ned Ludd
Silver $$ Contributor
I believe the question being asked here is with regard to commercial .223 Rem and 5.56 NATO ammunition. If someone either knowingly or accidentally prepares an unsafe handload that causes some sort of catastrophic failure, that really has nothing to do with the chamber. It means that the person is an idiot, and idiocy is not constrained to a .223 Rem or 5.56 NATO chamber. In fact, preparation of an unsafe handload is possible in any cartridge known and typically involves ignorance or lack of attention to the task at hand.
In my mind, the question here really should be whether any commercial 5.56 NATO ammunition is sold that could potentially cause a catastrophic failure when fired in a firearm specifically chambered for .223 Rem. If so, I would imagine it happened largely because the end user was unaware that such an occurence was even possible (i.e. was unaware of the potential differences between .223 Rem and 5.56 NATO ammunition and/or chambers). I also wonder whether certain firearms might be more at risk for such an event due to some inherently weaker design factor(s) and/or having the shortest possible .223 Rem throat. I have never personally heard of such an occurance.
In my mind, the question here really should be whether any commercial 5.56 NATO ammunition is sold that could potentially cause a catastrophic failure when fired in a firearm specifically chambered for .223 Rem. If so, I would imagine it happened largely because the end user was unaware that such an occurence was even possible (i.e. was unaware of the potential differences between .223 Rem and 5.56 NATO ammunition and/or chambers). I also wonder whether certain firearms might be more at risk for such an event due to some inherently weaker design factor(s) and/or having the shortest possible .223 Rem throat. I have never personally heard of such an occurance.
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As the question was posed to me the issue was with commercial 5.56, available just about anywhere, fired in a rifle with a .223 chamber. Nothing about AR or bolt gun, handloaded ammo or custom chambers. Just a question if I had ever seen a catastrophe due to a 5.56 round fired in a .223 chamber. And it would seem that none of you who have replied have also never seen or personally witnessed such an event. That's a good thing in my mind. I've seen too many rifle go boom due to other stupid reasons, most recently a .300 BLK in an AR-15 5.56. A 300 Savage round in a vintage Browning 25-06 didn't work so well either......
Thanks for your observations.
Thanks for your observations.
asyoung
Gold $$ Contributor
I have seen two. A well known AR manufacturer, won't mention the name as I don't think was necessarily their fault, was selling off some M4ish type AR's very cheap for a time several years ago. I saw maybe a dozen of them fire hundreds/thousands of rounds with no issues. But, two of them did have case ruptures, blew the magazines out the bottom and slightly bulged the lower.
All of those rifles were fed a mix of Federal XM193 ammo that was labeled 5.56 and Federal AE223 labeled, well, .223. Only the two that had issues had barrels stamped ".223", all the other barrels were stamped "5.56". Both the issues happened while shooting the 5.56 labeled ammo.
All of the ammo was 55 grain FMJ. After the 2 blow ups I chronographed the ammo and the XM193 was almost 300 fps faster than the AE223 through a 20" barrel.
It's been years since I've seen an AR barrel stamped just .223. Barrels I've seen (close to 100) stamped 5.56 have handled 5.56 ammo with no problems. Folks in the know tell me there are as many "mil spec" chamber dimensions as there are people with lathes and reamers so what's stamped on a mass produced barrel might not mean much.
But, you asked, and my answer is yes, I've seen it twice. It was enough to prevent me from using ammo labeled 5.56 in barrels stamped .223. But again, you just don't see that much anymore. Better yet, for my purposes, I try to not deal in any ammo labeled 5.56 when the .223 stuff does what is needed.
Advice worth what you paid for it,
Scott Young
All of those rifles were fed a mix of Federal XM193 ammo that was labeled 5.56 and Federal AE223 labeled, well, .223. Only the two that had issues had barrels stamped ".223", all the other barrels were stamped "5.56". Both the issues happened while shooting the 5.56 labeled ammo.
All of the ammo was 55 grain FMJ. After the 2 blow ups I chronographed the ammo and the XM193 was almost 300 fps faster than the AE223 through a 20" barrel.
It's been years since I've seen an AR barrel stamped just .223. Barrels I've seen (close to 100) stamped 5.56 have handled 5.56 ammo with no problems. Folks in the know tell me there are as many "mil spec" chamber dimensions as there are people with lathes and reamers so what's stamped on a mass produced barrel might not mean much.
But, you asked, and my answer is yes, I've seen it twice. It was enough to prevent me from using ammo labeled 5.56 in barrels stamped .223. But again, you just don't see that much anymore. Better yet, for my purposes, I try to not deal in any ammo labeled 5.56 when the .223 stuff does what is needed.
Advice worth what you paid for it,
Scott Young
thank you Sir. Appreciate the info.
JSH
Gold $$ Contributor
No
I think to many people put to much into “mil spec”. To my understanding in a nut shell, it means who was ever the cheapest got the bid.
I load my 223 to 5.56 pressure/data.
I was shooting milsurp 5.56 ammo in 223’s before this mythical problem came about, zero instances of any kind.
I think to many people put to much into “mil spec”. To my understanding in a nut shell, it means who was ever the cheapest got the bid.
I load my 223 to 5.56 pressure/data.
I was shooting milsurp 5.56 ammo in 223’s before this mythical problem came about, zero instances of any kind.
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