5.56 NATO and .223 Remington weapon/ammo confusion..

[MedWheeler]

I'm considering the purchase of what would be my first centerfire rifle, and I'm a little confused about things I hear regarding whether or not a firearm chambered for one will also safely handle the other. Some say it works both ways; others say it works one way only, and there is confusion about which way (example: NATO weapons can handle .223, but not the other way around, or vice-versa.)
So, I'll put it to a poll, and see which way the concensus here follows..

Edit: These two replies assume I'm considering an AR-type. They are correct; I forgot to mention that.

You will have to look to find an AR marked 223, the majority are marked 5.56 and that is what I would purchase. With it you can feel free to shoot either one.

You didn't state that the 5.56mm rifle you are looking at is an AR-15 clone, so whatever you find, I agree, make sure it's marked 5.56mm to be able to use both types of ammunition, like this SA vz-58.

 

[gotigers]

NATO and Wylde chambers can shoot both 5.56 and .223. The .223 chamber should only shoot .223. It really depends on manufacturer. Some .223 will handle both, but it is safer to go with a 5.56 NATO chamber. There are a lot of 5.56 chambered ARs, so it shouldnt be an issue finding an AR that you want.

 

[chrome_austex]

^ this, and ..

.. you can also check with the manufacturer to see if a specific rifle marked 223 is ok for 556.

 

[X-Rap]

You will have to look to find an AR marked 223, the majority are marked 5.56 and that is what I would purchase. With it you can feel free to shoot either one, beyond that I doubt anything will be settled.

 

[armoredman]

You didn't state that the 5.56mm rifle you are looking at is an AR-15 clone, so whatever you find, I agree, make sure it's marked 5.56mm to be able to use both types of ammunition, like this SA vz-58.

 

[Bear451]

As I understand it, the 223 and 556 rounds are nearly identical, but the 556 specification can stand higher pressures, so you can shoot 223 safely in a 556 gun, but not the other way around.

 

[hardluk1]

Only issue with shooting .223 in a 5.56 firearms is it may have cycleing issues with .223 as power levels are less. But it will fire in all 5.56 chamber firearms.

 

[HJ857]

For the OP, there's a couple other questions.

1) Is the intent of the rifle just general purpose or are you going for accuracy? If general purpose then the 5.56 chamber is the better choice.

2) Are you going to handload or buy milsurp ammo? If handloading ONLY, then I'd say the Wylde or .223 chambers. There are differences between 5.56 and .223, and while I haven't looked all that closely - I've never seen 5.56 NATO reloading dies.

 

[MedWheeler]

HJ857, the rifle will be for general sporting purposes, "just to have one", so to speak. It will definitely be shot for fun, and will likely be placed into service as a possible HD weapon as well once it and I are proven with each other.
Based on what I read, I will definitely be looking for one chambered in 5.56.
I had actually intended for this poll to only be open for three days, as I knew I'd get the information I wanted from you guys quickly, but it defaulted to the 30-day option during an edit, and I don't know if it can be cut short.

 

[oldpapps]

Just buying the weapon, go with one that is suitable for the 5.56 NATO chambering or the Wylde chambering. This will cover all bases.
I load all of my own ammo and tailor loads for each of my weapons, but having full options is always better than being limited.

 

[alsaqr]

Theres at least a dozen different .223/5.56mm chambers. Here are 8 of them.

Click on detailed .223 vs. 5.56 chamber reamer dimensions:

http://ar15barrels.com/tech.shtml

 

[rcmodel]

For me, No steadfast rule; depends on weapon/manufacturer/ammo.

A man has to know his rifles limitations!

If I had a 1965 Remington 40X benchrest rifle chambered in .223, I would not shoot 5.56 NATO in it because it would probably blow primers due to the tight chamber & bore.

If I had a 2005 CZ 527 .223, I would shoot 5.56 NATO in it.

Oh wait!
I do.

rc

 

[awgrizzly]

I think it's rather foolhardy determining an issue like this with a poll. A fact is not best decided by popular choice, especially involving safety.

You can shoot both .223 and 5.56 ammo in a 5.56 NATO or .223 Wylde. But you should avoid shooting 5.56 NATO in a .223 Remington caliber rifle. The AR platform is typically a 5.56 NATO.

The two chambers have different dimensions in the area between the throat and the rifling which apparently tend to develop different pressure levels. The dimensions of the two bullets are identical, stories to the contrary are a myth. The difference in cartridges is that the 5.56 may have a slightly hotter load and exceed SAMMI limits in the .223 chamber. Is this true? Maybe, maybe not... but if you purchase a 5.56 or .223 Wylde you don't have to worry about it.

 

[MedWheeler]

awgrizzly writes:

I think it's rather foolhardy determining an issue like this with a poll. A fact is not best decided by popular choice, especially involving safety.

..and adds:

But you should avoid shooting 5.56 NATO in a .223 Remington caliber rifle.

..and:

The difference in cartridges is that the 5.56 may have a slightly hotter load and exceed SAMMI limits in the .223 chamber. Is this true? Maybe, maybe not... but if you purchase a 5.56 or .223 Wylde you don't have to worry about it.

I put it to a poll because I knew it would not be a hard rule. Your response tells me you agree that there may be variables.

I have the information I need,and have made my decision. Thanks for all your input, though I know many of you will still keep chiming in..

 

[jmr40]

Same round, different name. The military calls it 5.56, loads their mil spec rounds a little hotter and uses a generous chamber to improve relaibility. Some folks seem to think that this justifies separating them into different chamberings. Some gun and ammo companies in an effort to cover their butt even make statements that 5.56 should not be used in 223 rifles.

The truth is that all guns have different chamber measurements and all ammo even in the same chambering is loaded to very different pressures. Let's use the 30-06 as an example. Randomly select a couple dozen rifles chambered in 30-06 and measure the chambers. You will find great differences between guns, even from the same manufacturer. Pick up a couple dozen boxes of factory 30-06 ammo and pressure test it. There will be a huge difference in pressure. There will even be a difference in pressure with ammo from the same box when fired in different guns because of differences in chamber and barrel dimensions.

The differences between various 30-06 rifles and ammo will not be any greater than typically found between 223 and 5.56. rifles and ammo. You will find some ammo that is right at the pressure limits in some guns, but not in other guns. You may even find some factory rounds that may not even chamber in some guns, while other ammo will. Some semi auto rifles will not function with some ammo.

I've seen a greater difference between various 30-06 rifles and ammo, and more problems resulting from it than I have between 223 and 5.56. Yet we do not separate 30-06 ammo into different names even though we could easliy break it down into 3-4 separate chamberings.

 

[Cosmoline]

If there actually is a .223-chambered rifle which is UNSAFE with 5.56 NATO rounds, I've never seen it. Has anyone? Can anyone identify even one rifle in .223 that should not be fed 5.56 because it might blow up?

 

[T Bran]

Every gun is different my REM 700 SPS is marked .223 since I reload and necksize it really doesnt matter. My Savage Axis is listed as .223/5.56 but I havent received it yet so I dont know what the bbl is marked once again it wont matter in my case. The hard part is now I'm going to have to find a way to keep the brass seperated. Maybe the easy way will be to use only one brand in the Axis and never in the REM.
If you dont reload just shoot what the barrel says to shoot.
T

 

[oldpapps]

Cosmoline,

I have a Remington 600 that was originally in .222 Rem, that I had punched to .223 Rem back in the mid 70s. I requested it to have a tight chamber and it does.
I refrain from firing my loads that I have worked up for my ARs in 5.56 and Wylde chambering. I have found that they flatten the primers a lot with a little flow back and make the bold hard to open. Do I think the little 600 will pop? No. But I don't need to tax it either.

Over the last 50ish years, there have been a lot of weapons chambered in some variation of the 5.56/223 and some of them I would not want to trust. As for the run of the mill Rem/Win/Ruger/AR, no problem.

The original question was for the purchase of a new weapon and what differences could be encountered. I stand by my view of going with one that the maker states is suitable for the 5.56 NATO, just to cover all bases.

 

[Kurt_D]

There is no confusion only people trying to push their opinion. 5.56 NATO can be and often is hotter than .223 Rem, PERIOD. 5.56 NATO chambers offer more lead than .223 Rem chambers for this reason, PERIOD. 5.56 NATO specs call for a thicker case head .223 doesn't.

Possible issues running .223 ammo in a 5.56 NATO chambered rifle - 1) possible slight loss of accuracy 2) gas system may have to be set to "adverse" "low pressure" or adjusted to allow more gas; in ARs and AKs- if the gun is in spec it'll run.

Possible issues running 5.56 NATO in a .223 chamber - 1) possible extraction issues 2) possible issues popping primers 3) possible deformed case heads and other high pressure signs 4) in an extreme case you could have a possible kaboom.

Now with that said - all import semi autos and most domestic semi autos either have a 5.56 chamber or something capatable such as the wyde chamber. That's why you rarely see an issue except for out of spec guns, cheap ARs, and .223 chambered varmint/target ARs, and often they only see extraction and popped primer issues. Also most people are running store bought .223 ammo anyway.

Bolt guns and single shots are typically chambered in .223; however their actions are typically much stronger than a semi and the issue with 5.56 ammo is usually extraction. You may possibly see other high pressure signs as well. Again though most people are running store bought .223.

So the rule is clear: 5.56 chamber - good to go; .223 chamber - stick to .223 or have possible issues up to and including a possible kaboom.

Also to add: 7.62 NATO/.308 WIN rule is almost exactly opposite of 5.56/.223 except for 7.62 NATO calling for thicker brass.

 

[mastiffhound]

One thing to remember is the Ruger Mini-14 is marked Cal. .223 but it is good to go with 5.56 nato ammo. At least the newer mini's are, I don't know about the older ones. It is also listed on the website as 5.56 NATO/.223 Rem.

 

[Redneck with a 40]

My Mini-14 is stamped .223, but the manual states that all 5.56 Nato rounds are safe to shoot in it. I've fired a few hundred 5.56 rounds with no issues.

 

[wally]

If you have a highly accurate, actual .223 barrel you'd not do it any good by shooting 5.56 NATO through it, but in todays sue happy legal environment if there was any actual safety issue nobody would make .223 reamers.

I shut up about this and change my tune when an actual case of damage from firing 5.56 in a .223 is documented -- and it'd be a miracle if a lawsuit wasn't involved! Many 5.56 barrels are marked .223 these days (Saigas fer instance).

I've shot 5.56 NATO through my .223 Weatherby Vanguard without issues although groups are a lot better with Remington .223 ammo.

 

[MedWheeler]

One thing to remember is the Ruger Mini-14 is marked Cal. .223 but it is good to go with 5.56 nato ammo. At least the newer mini's are, I don't know about the older ones. It is also listed on the website as 5.56 NATO/.223 Rem.

My Mini-14 is stamped .223, but the manual states that all 5.56 Nato rounds are safe to shoot in it. I've fired a few hundred 5.56 rounds with no issues.

Good to know, and sounds typical of Ruger firearms; always seem to be "overbuilt-tough"..

 

[T Bran]

My Savage AXIS is listed as 5.56/.223 on the website but the bbl is marked .223 so I'm not surprised at all of the confusion on the subject.
When in doubt refer to your owners manual.
T

 

[303tom]

.223/5.56 six of one, half dozen of the other...........