What’s the difference between .223 Remington and 5.56x45mm NATO?
Do you know?
They’re basically the same right…or are they? Will my gun blow up if I get it wrong?
You might be thinking about purchasing or building an AR-15, or even a bolt-action or single-shot rifle in one of these calibers and find yourself understandably confused.
Worry not, we’re here to help.
It turns out .223 Remington, 5.56×45 NATO, and even the oddball .223 Wylde have a lot in common, but the differences are important.
So, let’s talk about it. We’ll run you through the calibers and what sets them apart. Ultimately, you’ll have a better understanding of .223, 5.56, and .223 Wylde.
Table of Contents
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What is Safe, What Isn’t?
So What’s the Actual Difference?
In a word…pressure.
Or at least the possibility of pressure.
The .223 Remington was designed as a civilian cartridge. But, when the U.S. military showed interest in it and after NATO started testing it, they increased the pressure of the cartridge to improve reliability in the newly designed AR-15.
As with many things, it’s what’s on the inside that counts.
Even though the case and projectiles may be identical, the pressure difference between .223 and 5.56 NATO makes it inadvisable to shoot the 5.56 NATO out of a .223 chamber.
In a .223 chamber, the 5.56 NATO round doesn’t have that extra room to stretch its legs. Thus it starts building pressure sooner.
The increased pressure creates unsafe pressures, which can cause catastrophic failure.
I don’t know about you but “catastrophic failure” isn’t a phrase I want to be associated with my firearms.
Going the other way, a .223 in a 5.56 NATO chamber is 100% safe — just not as quite accurate as .223 ammo in a .223 chamber.
Choosing Between the Two
In years past, you had the option of getting an AR-15 in either .223 Remington or 5.56 NATO from most of the major builders.
But these days, basically every AR-15 on the market will be in 5.56 NATO or some other cartridge entirely like 6.5 Grendel, .300 Blackout, etc.
If you want a .223 Remington rifle, you’ll normally have to go the bolt-action route or get a barrel for your AR separate from the rifle.
But, why would you do that?
Accuracy.
If you want a REALLY accurate rifle, then .223 is the way to go. But the applications for this rifle are normally limited to punching paper and sometimes hunting varments.
For the vast majority of people, an AR-15 in 5.56 NATO is going to be the gold standard.
.223 Wylde: Best of Both Worlds
It really shouldn’t have taken as long as it did for somebody to look at the .223 chamber, look at the 5.56×45 chamber and go “Hey, you know what? I can make one version that’s better than both of them.”
Bill Wylde looked at the two chamberings and came up with a Goldilocks design that truly is the perfect middle-ground.
He designed a chamber with the leade angle and external dimensions of the 5.56, but the leade diameter of the .223.
This gives you a chamber where the gas expansion is tight and controlled because of the smaller leade diameter of the .223. But also one you can fire 5.56 through because of the 5.56-style leade angle and length.
In practical terms, this means that both 5.56 NATO and .223 Rem ammo perform equally well in the .223 Wylde chamber.
That said…the juice isn’t really worth the squeeze.
Yes, .223 Wylde is more accurate than 5.56 NATO. And yes, it can fire both .223 and 5.56 NATO completely safely.
But with the ability to create sub-MOA AR-15s in 5.56 NATO, the accuracy gain presented by using .223 Wylde really isn’t very much.
And almost never worth the price hike you’ll normally pay.
Best .223 Remington and 5.56 NATO Ammunition
First off, there is no such thing as .223 Wylde ammo. It’s a chamber…not a cartridge. (Like the blinker fluid of the AR-15 world…)
With that out of the way, these are some great ammo choices for you that DO exist!
1. American Eagle XM193 55-grain
A great 5.56 round that is the classic 55gr ammo, perfect for plinking, training, or taking a class with.
Prices accurate at time of writing
Prices accurate at time of writing
-
25% off all OAKLEY products - OAKLEY25
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2. PMC Bronze .223 55-grain
Good quality .223 ammo, still plinking ammo but also good when reliability is important.
Prices accurate at time of writing
Prices accurate at time of writing
-
25% off all OAKLEY products - OAKLEY25
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3. Federal Gold Match 69-grain
Need .223 that is accurate? Federal Gold Match has you covered. They know how to make accurate ammo while still keeping the prices reasonable.
Prices accurate at time of writing
Prices accurate at time of writing
-
25% off all OAKLEY products - OAKLEY25
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4. Wolf .223 Polyformance 55-grain
This is the truly budget stuff.
The steel-cased ammo isn’t allowed at all ranges so check the rules before bringing it out the first time. That said, it always goes bang (for us at least) and is dirt cheap.
Prices accurate at time of writing
Prices accurate at time of writing
-
25% off all OAKLEY products - OAKLEY25
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5. Speer Gold Dot Duty .223 55-grain
Speed Gold Dot Duty is a gold standard in defensive ammunition, this is what we load in most of our home defense AR-15s.
Prices accurate at time of writing
Prices accurate at time of writing
-
25% off all OAKLEY products - OAKLEY25
Copied! Visit Merchant
Conclusion
Hopefully, we answered all your questions about the differences between .223 Remington, 5.56×45 NATO, and .223 Wylde.
I know it’s confusing at first, especially if you’re new to the debate, but this should give you get you started when choosing the best chambering to meet your needs.
Or you can do what I did and pick up one in each flavor and call the debate settled.
What’s your preference in the .223 Rem vs. 5.56 NATO vs. .223 Wylde debate? Also, now that you know what chamber you want, take a look at our AR-15 Buyer’s Guide to choose your rifle!
63 Leave a Reply
Can I swap out my .223 Remington barrel (16”) on my Howa bolt action rifle for a 24” .223 Wylde barrel? I’m not at all happy with the accuracy of 16” barrel.
Having some work done to my old mini-14, it is chambered in .223. As part of the work I am rechambering it to WYLDE, primarily so as to be able to shoot whichever ammo I can find if it comes down to finding ammo.
For my nickel, if you are buying a new rifle and you like the caliber hecks yeah pay up and get the WYLDE, then it doesn't matter.
For pew-pew purposes, having both 5.56 and .223 rifles in you gun locker or bailout box or zombie vault, is not out of the question. I just use the .223 rifle for my daily or accuracy. I also only stock .223 in the locker and box/vault. This way, they can all be used for any reason, at any time, without mistakes of catastrophic failure.
Over the weekend I came across and add from Aim Surplus in which all of the 5.56 ammo was listed as 5.56/.223, or .223/5.56, even though the packaging was clearly labeled as 5.56 or as .223. I shot them an email (pun intended) about the fact that their marketing scheme was potentially dangerous since the 5.56 ammo should not be fired from a rifle chambered in .223. Their response was that they always label their ammo that way because they believe their customers are fully aware whether their rifles are chambered in 5.56 or .223 and will know which ammo they should use. Anyone else think that is a bad idea?
Yes I know the difference but I'm not new to firearms & ammo put 5.56 or 223 some people don't know the difference
I had a 5.56 16” cmv 1:7 and could not get good groupings with 62 grain and higher 5.56 ammo. I switched to 18” 223 wylde barrel, 1:8, put some 77gr in it, and pegged 3 out of 5 within 1/2” in the bullseye. Seems to me like Wylde is worth it.
Seems to me like getting a new barrel and completely different round was worth it...
“62 gr and above…”. The round wasn’t new. I tried the 77gr in the 16” cmv, too, with groupings over 1”
Perhaps the barel length, twist rate, and higher grain projectile had something to do with it
I fired the 77 gr out of both. I expected it to do better in the 1:7 twist 16” cmv 5.56 but it did not. The barrel length might have helped some but I would expect that to show up more at longer ranges.
Question? I am new to the AR-15 world, I've just built a AR-15, with the AERO-Precision Gen 2 Lower Receiver, Model X-15, and with a 223 Wylde 18" Barrel, Is it safe to shoot 5.56? Still learning!!, Thank you for your help..Clinton
Yes.
If you read the article you will see it is safe to shoot 223 and 556 in a 223 wylde barrel. Look at the chart above.
Why don’t you scroll up and read the article
My Savage MSR 15 Recon is 223 Wylde and can be bought around the $800 range even during Covid high prices. It has free float barrel with 5 R rifling and is rated as one of the most accurate rifles out there up to $2,000 price. Check the online reviews, Guns and Gear, Sootch and many others. Use 62 or heavier grain as it has a 1:8 twist for best results. Love this rifle!
I have a 223 wylde barrel on my ar15. I just bought a bunch of 556 loaded in 65 grain. Is it safe to shoot out of this barrel
Yes it is safe to shoot out of a .223 Wylde barrel.
Just bought a bunch of 556 loaded with 65 grain. Is it safe to shoot out of my AR15 with a 223 wylde barrel
If you read the article you will see it is safe to shoot 223 and 556 in a 223 wylde barrel. Look at the chart above.
A 556 NATO will shoot the 5.56 x45 and the 223 Remington. 223 Wylde is just a chamber it is not an ammunition
I bought a wylde so in the case of civil unrest, I can pick up any 5.56 or .223 ammo and use it without worry. Is the extra money worth the peace of mind knowing it won't blow up in my face? To me, it is.
You could have bought a 556 NATO and had the same advantages. They 556nato suits 556 x45 and 223 Remington. And it would also save you a little money. Remember, the 223 Wylde is just a hybrid of the 556 and 223
I mean you really aren't going to blow up your gun if you have a 5.56x45mm barrel and shoot .223, just the reverse is true. You really want the 5.56x45mm for SHTF situation in the first place. .223 is more of a light hunting and target shootingcompetition cartridge. But I can see the allure being that it will shoot .223 more accurately, I just wouldn't want to be reliant on .223 as a combat cartridge.
you do realize there is almost no difference in performance of 5.56 vs .223 ?
I would like to find an article with 2 identical rifles, 1 chambered in 5.56 and 1 in .223 Wylde. Both shooting PMC Bronze 55 grain .223 and comparing the accuracy at 100 yards. For decades I've know the difference between .223 and 5.56, but only in the last year have I heard that you lose accuracy shooting .223 out of a 5.56.
can a 5.56 nato ar-15 shoot .233 wylde
.223 Wylde is a chamber, not a cartridge. Wylde chambers can shoot 5.56 and .223!
It is the best of both worlds just read about it’s creation
A 556 NATO will shoot the 5.56 x45 and the 223 Remington. 223 Wylde is just a chamber it is not an ammunition
I have a bushmaster xm15 es2 and it is stamped 5.56 nato on barrel. Can I fire .223 Remington through it safely?
Yes!
Absolutely
On their website, Seekins Precision makes more than a few AR’s chambered in .223 Wylde. That’s how I became aware of, and curious about .223 Wylde. Thanks for the in depth explanation of Wylde, and including the difference between 5.56 and .223. My rifle is 5.56 NATO - so I’m good to go.
I recently build two AR15 carbines using kits i bought from a prominent online provider. One was a standard 16" 5.56, and the other a 18" 223 Wylde, and the cost for each kit saw almost the same, $329 and $359 respectively. That was before COVID 19 issue, so prices now may very, but my point is there wasn't much cost difference and the 223 Wylde has a full SS barrel. This was a great reference article when deciding what to buy. THANKS
Can my GALIL .223 safely use MAGHTECH/CBC 5.56 M193 NATO 55 GRAIN FMJ ammo which is widely available?
No. Anything marked 223 can ONLY fire 223. The Nato and the Wylde can fire either. It does not matter if it's a Galil or a Mini 14 if it says 223 it can only fire 223. Unless you want bad things to happen.
About the Mini 14, it is perfectly safe to use 5.56 Nato and 223.
The manual says it is safe. Also have seen a post were a phone call to Ruger confirmed this. I use 5.56 in my 2 ranch rifles and
never had a problem. I know it's misleading when it says on the rifle 223, no clue way they did that. There is a Ruger Mini 14 target version that is 223 only. If you have no manual, give Ruger a call.
You are 100% incorrect. The older Ruger mini 14 target rifles are chambered in 223 only and can only use 223 ammo. Do not use 556 in a rifle that is stamped 223 on the barrel. If it is stamped 556 than you can use either caliber.
The cartridges listed above are plinking quality. Far from a match or best. M262 Mod 1 from Black Hills is phenomenal up to and including 500 yards and if the wind isn’t significant can do very well at 600 yards in a match AR.
Mulligan
The first sentence should have stated: The cartridges listed above are mostly plinking quality, with the exception of Federal Gold Medal and Speer.
Also, I should have added to take advantage of heavier bullets a slow twist barrel is ideal.
In case anyone stumbles on this in the future: there is no relationship between bullet weight and barrel twist, only bullet length and barrel twist, and (more importantly) it's the opposite of what you state. Longer (generally heavier) bullets (may) need HIGHER twist rates to stabilize.
There is an excellent interactive stability calculator at the Berger website under Resorces > Ballistics > Twist Rate Stability
Thanks for the info. I'm new to this rifle business. Now I think I can start making a decision on a long gun.
Maybe some day you could do a review of the rifle caliber pistols of today.
Thanks
Well, not worth the extra money? Faxon Barrels are great and affordable not only are they .223 Wyld but also 5R. So much for trying to turn people off the Wylde barrels.
Sorry, fella, but you can't just say that certain ammo is more accurate than another. For instance, my 20", 5.56 barrel, with a 1:7 twist doesn't like any 55 gr. ammo that I've tried with it. Noted, I have only used factory ammo. A 55 gr. handload tailored to it might shoot well. I am not yet into handloading. What my particular barrel does like is Hornady 5.56x45mm NATO Frontier HFR320 75 gr HPBT, which is only $0.48 per round at Outdoor Limited. I can, and have shot many clover leaves with it. The best groups that I have shot were just under 1/2 inches, I am almost always less than 3/4, with the occasional flyer.
I think that I am forced to agree with "Mark", in his remarks, when he says that y'all must be getting kickbacks from the ammo manufacturers that you list as most accurate. I personally don't mind if you are receiving sponsorship monies from anyone. I do have a problem when it affects your partiality during an article. If you are going to accept money from manufacturers, you should tell the manufacturer up front that their support will not affect your partiality and, if their products don't hold up to snuff, not to be surprised if they don't get mentioned in your "best of" lists, or that they get called out on a lack of quality. If they do get called out, let them know that it is just a call for them to step up their game.
If you are not letting sponsorship monies affect your partiality, then you definitely need to get much more detailed about all the underlying conditions that were met for you to make certain assessments. To be honest, this is not the only article from Pew Pew Tactical that has made me think that your product assessments are influenced by a need to please your sponsors. I wouldn't be surprised if there are many others that have the same perceptions that I do. If you want to be taken seriously, you need to make sure that this perception is eliminated. I would hate for you to lose followers over misconceptions.
Thanks for the feedback.
We don't have sponsors, Federal or any other manufacturer or retailer had no involvement in this article.
It is also very easy to state that some ammo is more accurate than others, consistency and quality control goes a VERY long way in creating accurate ammo. In our testing, Federal Gold Metal has performed very well in a wide variety of calibers and weights. While results will very depending on barrel, brand, weather, shooter skill, etc.
That said - the article does not say that X ammo is more accurate than Y ammo. It simply stated that Federal Gold Metal is an accurate option.
I AGREE... WE SHOT EVERY WEEKEND AND SHOOT APROX 2,500 -4,000 EACH WEEKEND PER PERSON IN OUR COMBAT CARBINE CLASSES.... AND ALTHOUGH FEDERAL IS MORE EXPENSIVE THAN OTHER BRANDS IT IS ALSO MORE ACCURATE. AND IF SOMEONE WANTS TO CORRECT MY STATEMENT THATS FINE CAUSE I DO NOT WEAR MY EGO ON MY SHIRT SLEEVE......THANKS DAVID.
You may not wear your ego on you sleeve but you do type in all caps and that alone is just down right unethical in and of itself....
I have heard that a bolt gun chambered in .223 can safely withstand the pressure of a 5.56 cartridge. Is this true? I'd like to add a Ruger predator to my safe but I don't want to worry about swapping ammo between the bolt gun and my AR. Or... can the Ruger barrel be changed out for a 5.56 chamber?
Bolt guns are normally rated for higher pressure, but I would ask Ruger to be sure.
I realize this is a bit late. When the 223 came out, it was a result of the military adoption of the 5.56x45 for the M-16. It was reported back then that the 5.56 was a little higher pressure round than the 223. This was also reportedly different because of where they tested the cartridges peak pressure(the 5.56 at the mouth of the cartridge and the 223 on the body of the cartridge). I started shooting the 223/5.56 in the late 60's and have yet to see a 5.56 blow a 223 chamber. Hell, back then, no one really knew the difference. It was like firing surplus 30-06 ammo in a civilian 30-06. The 5.56 ammunition was good plinking and practice ammunition. If you ever see an instance where a 5.56 blows a 223 action, you might find out there was more to it than the wrong cartridge. Usually an excuse for bad reloading practices.
Just go with 5.56 chamber and you are gtg to use .223 as well.
Saw a 5.56 AR-15 That fired a .300Blackout. It did not look anything near as bad as the picture above. Not good that a 30 cal will even chamber in a .224
You guys must be getting a Kick-back from Federal; everyone who has tried American Eagle gets 3.5-4" groups at 100 yards. I shot about 50 rounds of it through a new rifle and almost threw the rifle out. I had some hot home loads for my bolt action and tried them, and my groups went from 4" to less than 3/4 inch instantly. No more factory ammo for me. That failure that you you picture in your article may have been due to 5.56; but only if following a squib with one.
I have done a lot of research into the difference, the standard chamber drawings show a slightly longer jump to the rifling for 5.56.
Standard cartridge dimensions for .223 and 5.56 are identical; the difference is in the wall thickness of the case (MIL spec is thicker; therefore less internal volume; therefore potential for higher pressure with an identical load).
Likewise, heavier bullets are longer, so at the same COAL, there will be less volume in the case; again more potential for higher pressures. Also with heavier bullets; they may have steeper ogives with the possibility of a standard length bullet contacting the rifling when chambered, causing an over pressure condition.
To have that level of catastrophic failure, you need to really screw up a lot more than one vs the other.
Wylde Chambers have proven no advantage to accuracy, and many have not chambered heavy 5.56 or heavy home-loads. In my experience most .223 chambers will chamber ammo that will not chamber in the Wylde barrels. Are most manufactures over reaming their .223 for safety? Maybe.
There is no difference in wall thickness. They are the same case.
NATO 5.56 case wall thickness is not the same, it’s thicker. Lake City is a noted example. Externally both 223/556 are identical but internally there is slightly less volume available.
I usually average 1.5-2MOA with American Eagle. As for Wylde/556/223 barrels you are wrong. If you reload, especially for bolt action you probably aren’t full length resizing the cases. That’s most likely why your examples will chamber in one rifle and not the other. 5.56 has the loosest chamber.
As for Wylde it is well known for greater accuracy even with heavier bullets in factory loads. Any chambering can shoot better than another with a random reload. Reloaders can tailor a load for a specific barrel, I’ve done it for years.
Thank you for the feedback.
No manufacturer or retailer had any involvement with this article.
American Eagle normally groups 2 MOA for me, that is consistent with other brands offering this variety of ammo.
The picture was only an example of a catastrophic failure, it is not credited to any specific event. We mention that in the caption of the picture.
Why is Speer Gold Dot Duty .223 55 grain a gold standard in defensive ammunition? Versus other brands producing similar ammunition...
I actually prefer Hornady TAP but I know Speer has had almost a monopoly in law enforcement for decades.
Great Article - maybe should have read before I spent loads of time researching the best 223 Wylde Upper and therefore the most expensive :-) However. A request. When comparing ammo prices could you make it a per round or per 100 deal and keep the playing field level? Thanks!
Maybe it is because .223 Wylde complete rifles tend to be a tad bit pricier at most retailers.
Hmm haven't really noticed a huge price difference NATO and Wylde barrels. Not really much of a difference if any at all really.
There was a considerable price difference 10+ years ago. Now Wylde barrels are extremely common even in budget builds for target and hunting rifles. Article is a bit out of date.