Confused about .223 vs 5.66 Nato

B

BeagleBoy360

CGN Regular
Rating - 100%
65   0   0
Location
London, ON
Hello,

I had just bought a Savage 12 off this site in .223 and was looking for some cheap plinking ammo.

My question to you guys is, can i shoot Norcino .223 ammo out of a .223 rifle, because a lot of people say yes you can, and other places say no you cant, that is only for AR-15 style rifles.

My question to you is, the cheap stuff I was looking at on SFRC like MFS and Norinco and stuff like that, that is listed as .223/5.56 NATO.

Can i shoot those without any danger of over pressure?


I tried to read as much as I can online, but if i found one website saying it was fine, i would fine another saying it wasn't fine.
 
A lot of the problems based on my reading are specifically with the 62gr, steel tipped, US made, 5.56 "green tip" ammo. They can apparently spike to nearly 80,000psi in a minimum cut 223 chamber.

The large difference appears to be from the throat of the barrel. 223 chambers when cut to minimum (usually match grade) dimensions have a very short throat. 5.56NATO ammo is designed to be fired from a long throat, military cut chamber. The shorter throat can spike pressure somewhat but not to any dangerous levels except for very specific rounds such as the green tip stuff. The military rounds do operate at a higher pressure. A problem occurs because the two standards (civilian SAAMI and military NATO) measure the pressure using different methods that are not directly comparable. SAAMI says 55,000psi for 223 and the NATO spec for 5.56 is 62,000psi or so. I'm not sure how the two pressure measuring techniques vary but it's food for thought.

As a general rule you should never fire 5.56NATO ammo in a 223 MATCH chamber.
Millions of 5.56NATO has been fired in regular 223 chambers without issue (though some say it erodes the throat faster).
I would very much avoid firing US made 62gr green tip ammo in a 223 chamber based on my reading.
 
if its labeled as 223 and sold in Canada then most likely the liability hurdles have been dealt with, or at least should have been.
In europe 223 and 5.56 chambers are one in the same, in north america 5.56 chambers are said to handle higher pressures than 223 chambers.
In China, anything goes, but if its being sold and labeled as 223 ammo in Canada it theoretically should be safe in your 223 chamber.
 
One nomenclature difference between North America and Europe is that 5.56x45mm is the metric designation for .223 Remington. Same way 7.62x51mm is one in the same as .308 Winchester. Unless it has the NATO tag as well, it isn't military spec ammo. Over here we automatically think 5.56 means 5.56 NATO but that isn't always the case, especially in Europe.

I've never seen or heard of a catastrophic failure due to swapping NATO ammo for civilian stuff, or vice versa, but have talked to some guys who have said shooting NATO surplus ammo wore out their bores/throats before 223 would have. Most civilian arms are proof tested to at least 130% max pressure so firing a 62,000psi round in a chamber designed for 55,000psi still falls within the margins; it's only 112% "max" pressure. As I said before though the two systems use different pressure measuring techniques that, as far as I've read, aren't directly comparable (thus why the "max" in in quotation marks). The article I was reading about the green tip surplus that spiked to nearly 80,000psi in a match 223 chamber still didn't cause a catastrophic failure (though I would assume the brass was difficult to extract.)

If someone can afford a match grade 223 and wants to fire surplus 5.56 NATO through it they have weird priorities. I'd be firing nothing but handloads through a match rifle (if I had one :().
 
Last edited:
I mostly agree with litnut. I do shoot steel cased, corrosive and 223/5.56 ammo regularly, but i have a beater SKS and a norinco .223 to plink at the range with, if they wear out faster, i'm not too worried about it.
I also have a savage model 12 and while i agree with him at not wasting it on surplus ammo, i know i am not a good enough shot to make match ammo with it (yet, maybe some day) so i make do with cheaper brands/loads untill i get good enough to warrant match ammo.
 
I was involved with the development of the 1:9 Savage 223. The chamber consists of a SAAMI 223 body dimension and a NATO 5.56 throat. the rifle will shoot any flavour 5.56 just fine. The tracer round won't stabilize, though.
 
Ganderite said:
I was involved with the development of the 1:9 Savage 223. The chamber consists of a SAAMI 223 body dimension and a NATO 5.56 throat. the rifle will shoot any flavour 5.56 just fine. The tracer round won't stabilize, though.
Click to expand...

best reply to a question on gunnutz by far. OP it doesn't get any more clear than this.
 
hometownhero said:
223 and 5.56 are not the same. Lots of stuff on google about the differences. Pressure are lots higher on 5.56 for one.
Click to expand...

Google us up some pictures of .223 chambered rifles that have blown up because the user shot 5.56 NATO ammo out of it. There must be millions of 5.56 round shot out of .223 rifles over the years so the there should be hundreds of pictures:rolleyes:
 
From what I understand they were interchangable before the invention of the internet.

Let's face it your not going to fire milspec ammo in your 223 target rifle. And I really believe that the only time your going to run into an issue is a low tolerence 223 chamber firing 556 .. But I try not to worry too much about this stuff
 
hometownhero said:
223 and 5.56 are not the same. Lots of stuff on google about the differences. Pressure are lots higher on 5.56 for one.
Click to expand...

Federal thinks they are, the last batch of 223 55 grain I purchased all came in Lake City NATO stamped brass, a quick investigation revealed they ran out of 223 stamped brass and used NATO stamped 5.56 in its place. They claimed it made no difference when shooting it out of 223. Mind you they are just a small ammo manufacturer so what would Federal know?
 
dizzy said:
Federal thinks they are, the last batch of 223 55 grain I purchased all came in Lake City NATO stamped brass, a quick investigation revealed they ran out of 223 stamped brass and used NATO stamped 5.56 in its place. They claimed it made no difference when shooting it out of 223. Mind you they are just a small ammo manufacturer so what would Federal know?
Click to expand...

Right from federal themselves

ht tp://le.atk.com/downloads/technical_bulletins/223VS556.pdf

Here are some others. They are not one in the same. But do what you want its your gun and your face beside that chamber. Isnt one rule of gun safety to only fire ammunition matching what is stamped on the barrel?

ht tp://www.humanevents.com/2011/02/15/223-remington-vs-556-nato-what-you-dont-know-could-hurt-you/

ht tp://www.thegunzone.com/556v223.html

ht tp://home.comcast.net/~mattmcginnis/reloading/223_versus_556.htm

ht tp://ultimatereloader.com/2010/11/19/ar-mpr-223-remington-vs-5-56-nato-whats-the-skinny/
 
Not too long ago the DCRA issued IVI ammo to civilian competitors to use competition. This ammo was supplied by the DND to be used in civilian .223 target rifles on DND ranges. Thousands of rounds were fired every year without a mishap. If the DND even suspected a hint of a problem with shooting issued IVI ammo, in civilian built rifles, by civilians on DND range, it never would have happened.
 
I was under the impression was the pressure of the NATO rounds had a higher pressure, because the powder charge is a tad bigger, that was all. The cases are exactly the same size are they not? I don't own a .223 or 5.56 yet, but I wouldn't lose any sleep over it. I have fired 1000's of NATO 5.56 rounds while serving with the CF, but I have not fired a civilian side .223, but I wouldn't bat an eye using either round in a .223 chambered rifle as the guys above have stated.
 
Ganderite said:
I was involved with the development of the 1:9 Savage 223. The chamber consists of a SAAMI 223 body dimension and a NATO 5.56 throat. the rifle will shoot any flavour 5.56 just fine. The tracer round won't stabilize, though.
Click to expand...

Doesn't that make it a 5.56 Nato spec chamber then? The longer leade from what I understand is the main difference from .223 to 5.56mm chamber. I didn't think that as far as external dimensions go that 5.56 Nato spec cases were any different from .223 Commercial spec cases.
 
crashcollins said:
Doesn't that make it a 5.56 Nato spec chamber then? The longer leade from what I understand is the main difference from .223 to 5.56mm chamber. I didn't think that as far as external dimensions go that 5.56 Nato spec cases were any different from .223 Commercial spec cases.
Click to expand...

Yes that is the difference. External they are the same but internal they are not. Nato brass is thicker and is loaded to 60,000cup whereas 223rem saami spec is 50,000 cup
 
You must log in or register to reply here.
Back
Top Bottom