Conventional Wisdom on .223 and 5.56?

[Jim Watson]

barrel has a tighter chamber and a shorter leade

Tighter and shorter than what? The old barrel, the specifications? SAAMI blueprint dimensions are for the minimum chamber, all tolerances are plus.

I once saw a chart of chamber measurements, you are not always getting what the label says.

I have seen some true .223 chambers with a very short throat.

Or the handy Stony Point - now Hornady - gauge to measure the "jump" of the ogive to the lands.

 

[citizenconn]

As others have said, most 223 chambered rifles will actually have a chamber closer to 223 Wydle or 5.56. Manufacturers do this for safety and liability reasons knowing that people will shoot 5.56 from a 223 rifle. If you are in doubt then take a chamber casting to see what you have.

You can still find 223 rifles with a true to spec 223 chamber that can have issues when shooting 5.56 ammo. But most modern bolt action rifles will handle it. The last rifle I had with a 223 chamber was a H&R Handi-Rifle. And I did have issues shooting 5.56 ammo in it. The extra pressure from 5.56 ammo would cause the action to pop open when the rifle was fired.

When it comes to reloading, the only difference between 223 and 5.56 is the actual load data ie. powder charge. You can't always go by case weight or case volume (water volume) since there is a variance between manufacturers. I have seen 223 brass that was thicker and less volume than military issue NATO Lake City brass. One will use the same reloading dies for both 223 and 5.56.

I have probably 50-60 .223, .223 Wylde and 5.56 chambered barrels from various manufacturers. I actually measured the chambers and tested various go/no go gauges on a sampling of them and found a wide range of measurements even within the same chambering that leads me to believe that each manufacturer does their own thing rather than adhering strictly to SAAMI specs. I found especially with bargain barrel manufacturers such as BCA that their 5.56 barrels are nowhere close to uniform even with each other. Only my .223 Wylde match barrels were strict on specs.

Most of my semi-auto barrels are 5.56 and .223 Wylde; I don't see a lot of .223 barrels except in bolt action rifles. Even among those it is only the older ones, 80s or earlier, where I would be especially careful about only firing .223 ammo in them. The ones I've seen also usually have a 1:10, 1:12 or 1:14 twist rate, limiting the weight of the projectiles for use in them anyway. Your mileage may vary.

If one is extremely concerned they should get their chambered measured and/or checked with go/no go gauges.

 

[doubleh]

I started shooting 223 a lot of years ago. First was a Contender with a 23" bull barrel and it has been amazingly accurate after I learned it's one little quirk, then a Savage bolt action followed but couldn't equal the the contenders accuracy. Then I added a handi-rifle and it was a complete disaster in the accuracy department. Then a long came an AR for coyote pursuit and it equaled the bolt action which is now gone. Now an encore with two 223 barrels has joined my collection. I have never purchased any 556 ammo, only that designated 223 to eliminate any problem. My choice has kept me from the cheap FMJ 556 but I am a handloader so no problem with that. Mag dumps are not my thing.

I have long been aware of the controversy but have never known anyone that had any problem that could be associated with shooting 556 in a 223 chamber gun.

 

[film495]

you have to really check with the manufacturor. .223 Remington is not the same a .223 Caliber, which some guns are stamped, but a.223 Caliber can shoot 5.56 if the manufaturor says so, but a .223 Remington which is a specific cartrdige and not a caliber designation can't shoot 5.56, and the manufacturor will tell you so. The .223 Remington is generally a target model, as the chamber is cut tighter and has smaller variances from my understanding, making it more consistent. So, IMHO, if you want a target or very accurate rifle with a little less reliability get a .223 Remington, if you want reliabiltiy and a 2-4" MOA firearm, cause that is good enough, 5.56 is more likely to just keep running, bit more velocity, will cycle the action assertively, and throw brass into outer space.

 

[CoalTrain49]

Are they reloads or factory ammo? If factory it shouldn't be too hard to separate. If it's just a bunch of reloads throw them out or buy a 5.56 NATO something or other.

Personally I wouldn't shoot any 5.56 in a Mini unless you know the weights of the bullets. <62 gr would be fine, above that you might be asking for trouble due to a barrel obstruction. The 5.56 freebore is double the length of the .223. The extra pressure of 5.56 NATO with 55-62 gr bullet won't matter. Consult the Hornady manual and you'll understand. They have 3 sections for .223/5.56.

 

[kmw1954]

I shoot exclusively 223 or is it .224" in two separate Savage rifles. One a model 10 and one a model 11. The receivers and bolts are the same. The model 11 now sports a model 12 26" Varmint barrel. It has a Freebore that allows me to load all bullets consistently .035" longer than suggested. Some of the lighter bullets, if I loaded them that long they would fall out of the case mouth. So yes I can load them longer than mag length and they still chamber and are not jammed into the lands.

So I decided I am going to keep my opinion of this subject to myself.

 

[12Bravo20]

I have probably 50-60 .223, .223 Wylde and 5.56 chambered barrels from various manufacturers. I actually measured the chambers and tested various go/no go gauges on a sampling of them and found a wide range of measurements even within the same chambering that leads me to believe that each manufacturer does their own thing rather than adhering strictly to SAAMI specs. I found especially with bargain barrel manufacturers such as BCA that their 5.56 barrels are nowhere close to uniform even with each other. Only my .223 Wylde match barrels were strict on specs.

Most of my semi-auto barrels are 5.56 and .223 Wylde; I don't see a lot of .223 barrels except in bolt action rifles. Even among those it is only the older ones, 80s or earlier, where I would be especially careful about only firing .223 only ammo in them. The ones I've seen also usually have a 1:10, 1:12 or 1:14 twist rate, limiting the weight of the projectiles for use in them anyway. Your mileage may vary.

If one is extremely concerned they should get their chambered measured and/or checked with go/no go gauges.

And as I stated before most manufacturers will cut their 223 chambers closer to a 223 Wylde or 5.56 chamber. Again they do this for safety and liability reasons. If you shoot full NATO spec 5.56 in a true SAAMI spec 223 chamber or a tight match grade 223 chamber then you will most likely have issues. Those issues can range from blown primers and other issues associated to higher pressures.

Now how many have actually took a casting of their rifle chambers to see what they really have? Probably not many. I have had issues shooting NATO 5.56 is a few rifles with 223 chambers. In bolt action rifles it caused primer blowouts and case head separations. With my H&R Handi-Rifle, ti would cause the action to pop open.

For those that have not had issues with shooting NATO spec 5.56 ammo in their rifles, see the first sentence of this reply. And remember just because nothing has happened on you does NOT mean that it hasn't or won't happen to others.

 

[Hokkmike]

Just to BE SURE I made certain that my rifle manufacturer stipulated that use of both rounds was approved - CZ-527.

 

[Spats McGee]

you have to really check with the manufacturor. .223 Remington is not the same a .223 Caliber, …a .223 Remington which is a specific cartrdige and not a caliber designation can't shoot 5.56, and the manufacturor will tell you so.…

Wait. So .223 is NOT necessarily the same as .223 Rem? That is news to me.

 

[film495]

Wait. So .223 is NOT necessarily the same as .223 Rem? That is news to me.

my limited understanding is a firearm stamped .223 or .223 Caliber, does not necessarily mean .223 Reminton, and may be fine with 5.56 NATO in it. whatever the manufacturor says. Ruger I think did this for decades with the Mini-14, and says they can all shoot .223 Reminton or 5.56 NATO, many are stamped .223 Caliber

 

[CoalTrain49]

I wish people would stop using the word caliber (bore diameter) when discussing specific cartridges.

When one buys .224 dia. bullets they are buying bullets foe a rifle with a .223 bore. Lots of rifles in production with that bore dia, but they chamber different cartridges.

I don't expect everyone who isn't a reloader to understand this. Even some so called sports writers don't know the difference and they continue to add to the confusion. They would do themselves and everyone else a favor by reading at least one reloading manual cover to cover.

 

[Jim Watson]

I wish people would stop using the word caliber (bore diameter) when discussing specific cartridges.

When one buys .224 dia. bullets they are buying bullets foe a rifle with a .223 bore. Lots of rifles in production with that bore dia, but they chamber different cartridges.

I confess to sometimes saying "caliber" when "cartridge" or even "chamber" is meant.

But we have a couple of countervailing errors here.
The nominal BORE diameter of a .223 Remington is .219" (which is 5.56mm in French), the GROOVE diameter is .224".
There is no .223" dimension in a .223 Remington barrel.

Or most other .22 centerfires, my thought is that we have the .218 Bee, .219 Zipper, .220 Swift, .221 Fireball, .222 Remington, .223 Remington, .224 Weatherby, and .225 Winchester that all shoot .224" bullets.
But .22 Hornet (original), .22 Jet, and .22 Savage Hi Power don't.

But hey, it is not important like the distinction between "clip" and "magazine."

 

[citizenconn]

I wish people would stop using the word caliber (bore diameter) when discussing specific cartridges.

When one buys .224 dia. bullets they are buying bullets foe a rifle with a .223 bore. Lots of rifles in production with that bore dia, but they chamber different cartridges.

I don't expect everyone who isn't a reloader to understand this. Even some so called sports writers don't know the difference and they continue to add to the confusion. They would do themselves and everyone else a favor by reading at least one reloading manual cover to cover.

I'm with you. I always try to use "chambering" and get a lot of aggro for it. Oh well. I'm getting older, on my way to old, and was raised when words were used to differentiate specific meanings.

An aside, so not necessary to read: I retired from private industry in 2001 and have been working as a full-time college instructor and librarian since then and with each year I find college students know less and less of anything in general. Facts and information that was taken as common knowledge in the era when I grew up are seen by most of my students as unknowable relics of the past and unnecessary to know in the era of Google. I will now go out in the yard and shout at kids to get off my lawn.

 

[Jim Watson]

.223 Remington is not the same a .223 Caliber

This is one of those News To Me items. Does it also mean a .40 Auto is not the same as a .40 Smith & Wesson and a .45 Auto is not the same as a .45 ACP, etc., etc.?

 

[hso]

Have y'all ever seen a .223 rifle that was actually damaged by shooting 5.56?

No

 

[film495]

This is one of those News To Me items. Does it also mean a .40 Auto is not the same as a .40 Smith & Wesson and a .45 Auto is not the same as a .45 ACP, etc., etc.?

no, but I think for example it means .45 ACP, does not mean the same thing as .45 Caliber. It would be bad if people started loading .45 Colt into their 1911s.

 

[alsaqr]

So I guess my question is this: Have y'all ever seen a .223 rifle that was actually damaged by shooting 5.56?

No. Since 1968 i've fired at least 100,000 rounds of M193 5.56mm ammunition in .223 chambers.

BTW: When it comes to AR-15 barrels, especially the least expensive ones; so called .223 SAAMI spec chambers are all over the place. Contrary to popular belief, most chambering is done by day labor. i've seen out of round .223 chambers.

Some folks have actually tested this stuff:

5.56 vs .223 - What You Know May Be Wrong - LuckyGunner.com Labs

Andrew of Lucky Gunner Labs explores the differences between .223 Remington and 5.56mm NATO ammunition - and the results may surprise you!

www.luckygunner.com

 

[film495]

I agree with the sentiment in this thread that the use of the word Caliber becoming common to mean Cartrdige, makes any .223 Remington, 5.56 NATO question 100 times more confusing than it should be. Just follow the basic rule, that you should not fire the wrong Cartrdige in a firearm. They stamp in on the gun. If unsure check with the manufacturor. How long before saying Caliber to mean Cartrdige has people trying to load and fire .45 Colt in their 1911s becuase .45 Colt and .45 ACP are the same Caliber? Just saying. The industry confuses the heck out of people with this and they should stop doing it IMHO.

 

[Jim Watson]

I also consider the purpose and service life of the rifle.
I am not going to shoot surplus or econoball in my 28" Krieger FTR barrel. It is not good enough for the job, so why burn barrel life?

I have, of all things, some Malaysian surplus ersatz M193. I shot it in my stock AR when I was dabbling in 3 gun. But otherwise I have used it to assemble Mexican Match for my 788.

 

[Larry in wyoming]

Mexican Match?

 

[someguy2800]

When this subject comes up I usually smile and keep my mouth shut because what people think they know about chamber dimensions and pressures is usually BS and there is no talking them out of it. The hand loaders know.

 

[12Bravo20]

As a gunsmith, I have seen issues with a few rifles with 223 chambers that had issues with NATO spec 5.56 ammo. I have personally had issues shooting 5.56 in Handi-Rifles I have also took casts of different rifles with 223 chambers and the dimensions were all over the place. Chamber cast dimensions have ranged from tight 223 match chambers to 5.56 chamber dimensions and everything in between. And I will say it a third time. most manufacturers will cut their 223 chambers on the large side knowing that people will shoot 5.56 ammo in the rifles. Again this is for safety and liability reasons.

And YES there is a pressure difference between NATO spec 5.56 ammo and 223 ammo. And if one is in doubt about their particular rifle, then I highly suggest getting a chamber casting down to see what the dimensions are.

 

[theotherwaldo]

I shoot a lot of reloads in my AR's.
I trim all of my brass to .223 standard length.
Keeps things simple.

 

[12Bravo20]

I shoot a lot of reloads in my AR's.
I trim all of my brass to .223 standard length.
Keeps things simple.

Case dimensions are the same for both 223 and 5.56. What is different is the reloading data. I know Hornady does publish 5.56 data along with 223 data. And I have seen commercial 223 brass that is thicker than NATO 5.56 brass and visa versa. Case thickness and water volume will differ depending on the manufacturer.

 

[DukeConnor]

Depends on the ammo