Can i shoot 556 NATO out of my AR-15

[WWIII]

So, what Armalite is saying essentially is it's safe, but we made changes to our chamberings anyway... just beacuse we had nothing else to do one day...!?

I've read this bulletin before and believe that it's a walking contradiction unto itself... made necessary because Armalite, for a very long time, cut .223 chambers in their AR's when they should have been using NATO chamber specs... I know, I have one, and it only sees .223...

The bottom line is this, if you want to be macho and risk your equipment or your safety, go right ahead, but I'm not doing it, and won't shoot with you if you do...

Out.

I live in the real world not in a theoretical. Facts always speak louder than opinions. The facts are; based on thousands of Armalite AR15 rifles chambered in 223 rem which have shot MILLIONS of 5.56 nato rounds for 20 plus years there seems to be no evidence to support claims of it being unsafe.

The theory of it being unsafe has not proven to be a fact.

 

[jennis]

The above statement , c/o WW III , should be considered the 'holy grail' for this whole 556/223 debacle

 

[easy]

Dimensionally, 5.56 and .223 ammo are identical, though military 5.56 ammo is typically loaded to higher pressures and velocities than commercial ammo and may, in guns with extremely tight "match" .223 chambers, be unsafe to fire.

The chambers for .223 and 5.56 weapons are not the same either. Though the AR15 design provides an extremely strong action, high pressure signs on the brass and primers, extraction failures and cycling problems may be seen when firing hot 5.56 ammo in .223-chambered rifles. Military M16s and AR15s from Colt, Bushmaster, FN, DPMS, and some others, have the M16-spec chamber and should have no trouble firing hot 5.56 ammunition.

Military M16s have slightly more headspace and have a longer throat area, compared to the SAAMI .223 chamber spec, which was originally designed for bolt-action rifles. Commercial SAAMI-specification .223 chambers have a much shorter throat or leade and less freebore than the military chamber. Shooting 5.56 Mil-Spec ammo in a SAAMI-specification chamber can increase pressure dramatically, up to an additional 15,000 psi or more.

The military chamber is often referred to as a "5.56 NATO" chamber, as that is what is usually stamped on military barrels. Some commercial AR manufacturers use the tighter ".223" (i.e., SAAMI-spec and often labeled ".223" or ".223 Remington") chamber, which provides for increased accuracy but, in self-loading rifles, less cycling reliability, especially with hot-loaded military ammo.

The Oracle explains it as plainly and factually as can be. If you don't understand this, you're a few french fries short of a potato.

 

[czuser]

yes you can shoot 556 from a 223. there is no diffrence except the thickness of the brass. military brass is thicker than civie brass. so if you reload you will have less powder volume. its very very safe to shoot.

Just say you don't know.
Cuz they are dimensionally not identical.

 

[beltfed]

The Oracle explains it as plainly and factually as can be. If you don't understand this, you're a few french fries short of a potato.

It does, does it?

"Dimensionally, 5.56 and .223 ammo are identical, though military 5.56 ammo is typically loaded to higher pressures and velocities than commercial ammo and may, in guns with extremely tight "match" .223 chambers, be unsafe to fire.

The chambers for .223 and 5.56 weapons are not the same either. Though the AR15 design provides an extremely strong action, high pressure signs on the brass and primers, extraction failures and cycling problems may be seen when firing hot 5.56 ammo in .223-chambered rifles. Military M16s and AR15s from Colt, Bushmaster, FN, DPMS, and some others, have the M16-spec chamber and should have no trouble firing hot 5.56 ammunition.

Military M16s have slightly more headspace and have a longer throat area, compared to the SAAMI .223 chamber spec, which was originally designed for bolt-action rifles. Commercial SAAMI-specification .223 chambers have a much shorter throat or leade and less freebore than the military chamber. Shooting 5.56 Mil-Spec ammo in a SAAMI-specification chamber can increase pressure dramatically, up to an additional 15,000 psi or more.

The military chamber is often referred to as a "5.56 NATO" chamber, as that is what is usually stamped on military barrels. Some commercial AR manufacturers use the tighter ".223" (i.e., SAAMI-spec and often labeled ".223" or ".223 Remington") chamber, which provides for increased accuracy but, in self-loading rifles, less cycling reliability, especially with hot-loaded military ammo."

Sounds more like subjective drivel as opposed to hard science to me - but then again I'm not made of potato...
I see a lot of guys reading into what has been posted prior and basing their opinion on it rather than digging for the hard truth.

The fact of the matter is not every single round is going to give the exact same pressure reading as the last or the next one being fired, and wouldn't if it was shot in a near identical rifle.
I'm positive they engineer a wide safety margin into all chambers.
The fact they have called attention to the 5.56 and .223 differences is for liability sake.
Can it? Sure. Will it? Not necessarily....

 

[acrashb]

Sounds more like subjective drivel as opposed to hard science to me - but then again I'm not made of potato...
[...]
I'm positive they engineer a wide safety margin into all chambers.
[...]
Can it? Sure. Will it? Not necessarily....

1) not at all - "may" and similar phrases are used because they can't guarantee, based on variability in design and build. If they said "will", which implies "every time", they'd be wrong and might then be in trouble. "should have" is the same thing - as soon as they say "will have" and someone has a problem in a Bushmaster, it makes a lawsuit easier. It's just cautious language.

2) They do, so it's "safe", maybe, but running a thing beyond its median spec for long periods of time will shorten that thing's lifespan. To put that in perspective, car manufacturers build a wide safety margin into transmissions. Which are often the first things to go when someone hops-up the engine.

3) This is a personal choice about risk. I wouldn't do it, others will - my concern is that people understand that they are almost certainly stressing the system beyond its design when they accept the risk. Less so with AR's (they're built for 5.56 generally, so the possible (likely) extra pressure from running 5.56 in a 223 chamber is better supported by the system), but more so with sporting .223 rifles.

 

[WWIII]

I’m still waiting for some of you to provide actual instances from credible sources where unsafe incidents have occurred to support the unproven theory of 5.56 nato being unsafe to shoot in modern 223 rem chambers. If you could at least provide some incidents we could include those as facts, but the only facts I see so far is “MILLIONS OF 5.56 NATO HAVE BEEN FIRED IN 223 REM CHAMBERS WITH NO INCIDENTS”. That is fact. Please provide some facts rather than theory. Gentleman...waiting

 

[acrashb]

I’m still waiting for some of you to provide actual instances from credible sources where unsafe incidents have occurred to support the unproven theory of 5.56 nato being unsafe to shoot in modern 223 rem chambers.

There are certainly cases of overpressure popping out primers (Armalite alludes to that in their writeup, among other things). Beyond that, I don't have anything specific. Most KB's are from gross overpressure (loading mishaps etc.) and are tough to diagnose beyond that - and early failure of a system through continuous, non-catastrophic overpressure is unlikely to be noticed or reported.

So, you still think it's OK to put a blower on a car's engine without some work on the tranny?

 

[acrashb]

only facts I see so far is “MILLIONS OF 5.56 NATO HAVE BEEN FIRED IN 223 REM CHAMBERS WITH NO INCIDENTS”. That is fact.

It's not a fact. It's a fact that people do it because surplus used to be cheap, but I am not aware of any actual evidence about numbers, let alone millions. If you have access to a study done by a credible researcher who has established this large number, incident-free, let's see it.

 

[Gunnerlove]

 

[alexD92]

I'd be curious to see if there's accelerated throat erosion in the chamber of a .223rem rifle when shooting 5.56 "milspec" ammo in it.

 

[acrashb]

It would be interesting; someone would need a borescope and a lot of spare money / time. I don't know if anyone has already done this.

 

[Gormley Green]

I shot about 200 rounds of 5.56 out of a Mini-14 target model. No jams, no unusual explosions.... I'd do it again if I could buy it again, it was a lot cheaper than the .223 fmj I'm buying now.

 

[WWIII]

It's not a fact. It's a fact that people do it because surplus used to be cheap, but I am not aware of any actual evidence about numbers, let alone millions. If you have access to a study done by a credible researcher who has established this large number, incident-free, let's see it.

You mean like all the credible studies done to support this theory - zero? My point is, contrary to this theory there appears to be lack of sufficient evidence pointing to any real unsafe instances from shooting 5.56 Nato in a modern 223 rem SAMMI spec chambered firearm .

Bottom line is - just like ArmaLite stated RE:

Occasionally a non-standard round (of generally imported) ammunition will fit too tightly in the leade, and resistance to early bullet movement can cause elevated chamber pressures. These pressures are revealed by overly flattened primers or by powder stains around the primer that reveal leaking gasses.

The first few rounds of ALL ammunition, from whatever source or lot, should be checked for signs of pressure or any other defect before firing large quantities. If you have a problem, you can generally bet that the ammunition meets neither SAAMI nor NATO specifications.

 

[Demon971]

I wouldn't believe firing 5.56 from .223 would pose much of a safety hazard, however firing a lot of the ammunition out of it would cause the chamber and barrel greater stress and wear than what it's designed for. The chances of errors also increases in consideration to the extra variables. In essence, it would simply reduce it's effective "life" a number of rounds under what it's projected to achieve.

Like how if you always floor the pedal in your car, you'll wear down the engine much faster than if you used moderated increments in acceleration. You could do either or and the engine will still run fine (for awhile).

The whole issue with ammunition 98% identical to one another is just a matter of protracted use. Use a little of both, in moderation, there should be no harm.

 

[cal9mm]

h**p://ammo.ar15.com/ammo/project/hist_diff.html

props to ar15.com

 

[beltfed]

1) not at all - "may" and similar phrases are used because they can't guarantee, based on variability in design and build. If they said "will", which implies "every time", they'd be wrong and might then be in trouble. "should have" is the same thing - as soon as they say "will have" and someone has a problem in a Bushmaster, it makes a lawsuit easier. It's just cautious language.

Thanks for the lesson.
I've designed, wrote specifications for, administered and have managed enough projects to know CYA language when I see it.

2) They do, so it's "safe", maybe, but running a thing beyond its median spec

Says you.

for long periods of time will shorten that thing's lifespan. To put that in perspective, car manufacturers build a wide safety margin into transmissions. Which are often the first things to go when someone hops-up the engine.

Yes, your analogy is making this comprehension stuff soooo much easier.

3) This is a personal choice about risk. I wouldn't do it, others will - my concern is that people understand that they are almost certainly stressing the system beyond its design

Again, your opinion

when they accept the risk. Less so with AR's (they're built for 5.56 generally, so the possible (likely) extra pressure from running 5.56 in a 223 chamber is better supported by the system), but more so with sporting .223 rifles.

You are getting just a little too arrogant in your posts, so I'll end my involvement here.

Suffice to say you and I haven't done the engineering on this, and we'll agree to disagree.

 

[kenjuudo]

You mean like all the credible studies done to support this theory - zero? My point is, contrary to this theory there appears to be lack of sufficient evidence pointing to any real unsafe instances from shooting 5.56 Nato in a modern 223 rem SAMMI spec chambered firearm .

Bottom line is - just like ArmaLite stated RE:

I find it interesting that you choose a source who has a monetary dog in the fight to put your money on. Why is Armalite more deserving of your homage than an independent third party such as SAAMI...!? Selective sourcing and your anecdotal "millions of rounds" comment suggests a bias based on opinion alone rather than the engineering data that leads organizations like SAAMI to take the positions that they do.

I'll stick with science and check the macho he-man "the science must be wrong" #### at the door. I'm thinking that you're the kind of guy that has to find out that the fire is hot by sticking his hand in it... so here's hoping that you (or more importantly the people next to you) don't get burned.

 

[kenjuudo]

h**p://ammo.ar15.com/ammo/project/hist_diff.html

props to ar15.com

This.

And note that the Oracle reinforces my earlier point with regard to Armalite... they changed their chambering in 2001 from .223 to 5.56... why do you suppose they did that...!? Interesting how they change their tech on the back end and cover their asses out the front with WWII's famous bulletin... they have money (liability) at stake on the inside, and money (reputation) at stake on the outside... two problems each requiring a different and contradictory solution... a two headed dilemma.

 

[WWIII]

I find it interesting that you choose a source who has a monetary dog in the fight to put your money on. Why is Armalite more deserving of your homage than an independent third party such as SAAMI...!? Selective sourcing and your anecdotal "millions of rounds" comment suggests a bias based on opinion alone rather than the engineering data that leads organizations like SAAMI to take the positions that they do.

I'll stick with science and check the macho he-man "the science must be wrong" s**t at the door. I'm thinking that you're the kind of guy that has to find out that the fire is hot by sticking his hand in it... so here's hoping that you (or more importantly the people next to you) don't get burned.

SAMMI - Independent third party??? Now your really blowing smoke rings out of your a$$. SAMMI gets its funding from the Sporting Arms Industry - Not the Military - you get it (Bias). Now why would the Sporting Arms Industry want you to use cheap mil surp ammo when you can buy their expensive sporting ammo. SAMMI relies on funding from companies such as Remington, Winchester, Black Hills, Barnes etc. SAMMI is about as independent as the United Nations.

Why would ArmaLite Inc put its corporation in legal limbo by officially endorsing use of 5.56 nato in its AR15, 223 rem chambered rifles? Waiting...

If you can’t understand millions of rounds of 5.56 nato have been fired out of AR15, 223 rem chambers without incident then I don’t expect you‘re capable of understanding the above self-explanatory precautions to take prior to using 5.56 in a 223 rem chamber. So I would suggest for uber safe people like you to simply not use 5.56 nato in 223 rem chambers and you will never have to worry about it.