5.56 or 223

Posted by: Cooper Woods

5.56 or 223 - 01/27/09 09:18 PM

Is there any difference in the 5.56 and the 223? Can you shoot eather one in the r-15?
Posted by: Tjkiller

Re: 5.56 or 223 - 01/27/09 09:24 PM

they are interchangeable, i believe the 5.56 military chamber has a slightly longer throat. If im wrong feel free to correct me. either round will shoot good in either chamber.-so im told
Posted by: William

Re: 5.56 or 223 - 01/27/09 09:25 PM

Some say you shouldn't but I have fired a lot of 5.56 in any number of .223 Remington chambered rifles and have never had any issues whatsoever. I haven't found most 5.56 ammo to be quite as accurate as most good factory .223 and because it's all been fmj I wouldn't consider it for hunting.
Posted by: DeathPenalty

Re: 5.56 or 223 - 01/27/09 09:27 PM

5.56 is loaded to NATO spec 60,000 CUP. SAAMI spec .223 is 50,000 CUP.
Posted by: Smiter

Re: 5.56 or 223 - 01/27/09 09:32 PM

They are loaded to different pressures and are not interchangable. You can shoot 223 in a 556, but vice versa is at your own risk. You can probably (many have) get by with it for a while, but you are rolling the dice.

Google ammo oracle.
Posted by: blackhawk309

Re: 5.56 or 223 - 01/27/09 10:32 PM

I have a R15, they are chambered for .223 only. Most AR's will shoot either and are stamped on the lower "5.56/.223". The R15 does not have that on the lower. On the barrel it says .223. I will not shoot 5.56 in mine. There's no advantage of shooting 5.56 anyway. .223 ammo is just as cheap as the 5.56 stuff.
Posted by: 5spd

Re: 5.56 or 223 - 01/27/09 10:44 PM

Remington reps say do NOT shoot 5.56 in the R15. Its chambered only for the .223 commercial round. BBL is stamped .223, lower is not stamped since you can swap uppers that do take the 5.56 & .223, or a .204 upper etc.
The 5.56 has a longer throat to handle the 5.56 pressures and what not, there is a difference.
Posted by: Cooper Woods

Re: 5.56 or 223 - 01/27/09 11:26 PM

Thanks for all the info. Thats what I was wondering about.
Posted by: FALFire

Re: 5.56 or 223 - 01/28/09 11:35 AM

This subject has come up here many, many times.

I've fired 1000's of 5.56 rounds thru several of my 223 AR's and never had a problem. The only extractor I ever damaged was on my 243WSSM and I was really pushing the loads when it spiked and chipped the extractor lip.

The AR has a very strong lock up design and will handle a lot of pressure.

The Remington Rep advises against it and for good reason, they want you to purchase their factory high dollar ammo, that's how they make money.
Posted by: seaaggie

Re: 5.56 or 223 - 01/28/09 11:46 AM

Quote:

they are interchangeable, i believe the 5.56 military chamber has a slightly longer throat. If im wrong feel free to correct me. either round will shoot good in either chamber.-so im told



the 5.56 is also a much higher pressure...the chambers are different, the 556 does have a longer throat, and the cartridge itself has a slightly longer neck. you can put .223 down a 5.56 all day long, but be careful going the other way
Posted by: foxxpro

Re: 5.56 or 223 - 01/28/09 12:41 PM

I wouldnt do it unless it is stamped on the barrel, 5.56/223. It is not worth it. All military spec guns that can shoot both will be stamped.
Posted by: Hidalgo

Re: 5.56 or 223 - 01/28/09 01:18 PM

OK...."IF" 5.56 NATO ammunition was safe to shoot in your .223-chambered firearm, I have never understood why you would even consider it anyway?.....

(a) Any military ammo that you would use is going to be FMJ and therefore unsuitable (and unsafe) for hunting.

(b) Using military ammo for "practice" is not going to help your accuracy when you go hunting with your .223 loads, so why bother?

(c) If you're only interested in "burning powder" then wouldn't the bulk .223 ammo that is available from Cabelas and other locations a better choice since it actually fits your chamber properly?...And in those quantities wouldn't it be lucrative to reload your own?

Sorry....I just don't understand why you'd take the risk of damage to your weapon (or yourself) when there are far better options available.
Posted by: Evil_Lurker

Re: 5.56 or 223 - 01/28/09 01:33 PM

I really don't understand why 5.56 NATO ammo would be "unsafe" in a .223 chambered AR, either.
They both use the same barrel blanks and bolt.
The 5.56 NATO is small-base sized, so it's going to chamber loose in either one.
Other than the 5.56 only being available in FMJ, I don't see the problem.

If you've got a bolt gun chambered in .223, all bets are off.

You guys are aware there are such things as "proof" rounds, correct?

Quote:

Each weapon and component considered vulnerable to the effects of a rapid change in pressure, for example barrels, breech blocks and bolts, will be tested by firing one dry round at a corrected minimum of 25% over pressure and one oiled round at a corrected minimum of 25% over pressure. 25% over pressure means 25% in excess of the Service Pressure (Pmax). The Service Pressure is defined as the mean pressure generated by the Service Cartridge at a temperature of 21°C. Such a high pressure proof is conducted with both the weapon and ammunition conditioned to an ambient temperature of 21°C.

Each weapon will be individually tested, from an ammunition lot that produces a minimum corrected mean chamber pressure in accordance with the table below:[1]

Corrected Proof Pressure Requirement (Service Pressure (Pmax) + 25%)
5.56 mm (5.56x45mm NATO) Designed to chamber NATO ammunition Service Pressure Pmax (MPa / (psi) 430 / (62,366)
Proof Round Pressure Requirement (MPa / (psi) 537.5 / (77,958)
Pressure recorded in NATO design EPVAT Barrel with Kistler 6215 Transducer or by equipment to Commission Internationale Permanente pour l’épreuve des Armes á Feu Portatives (C.I.P.) requirements



Posted by: FALFire

Re: 5.56 or 223 - 01/28/09 01:44 PM

The only reason really I can think of to shoot the 5.56 Mil surplus ammo is for tactical training or just plain blasting ammo on the cheap, of course I geuss none of it is cheap these days. I agree when hunting, one should use a quality soft point or hp round to do the work. Shooting tin cans with fmj is the only way I would consider using it these days.
Posted by: Evil_Lurker

Re: 5.56 or 223 - 01/28/09 01:50 PM

Well, I used a couple boxes of the .223 FMJs to get my AR on paper when I mounted my new scope and EOTech, and to zero my irons.
It was $3.98 a box a couple years back.
I save some for that kind of situation.
Posted by: Hidalgo

Re: 5.56 or 223 - 01/28/09 01:54 PM

A couple of BOXES to get it on the paper?
Posted by: Evil_Lurker

Re: 5.56 or 223 - 01/28/09 01:57 PM

Quote:

A couple of BOXES to get it on the paper?




Yeah, to get the Nikon, EOTech and BUIS all zeroed, it took a couple of boxes. I guess I should have said zeroed, not "on the paper".

Sorry.
Posted by: bigwheeler

Re: 5.56 or 223 - 01/28/09 02:02 PM

The technical reason for not using 5.56 in .223 is the neck can get pinched
in the throat and therefore pinch the bullet, spiking pressures way above
specs for the military round. Winchester has a good article on it if I remember
correctly. Ar15barrels.com has a good diagram of all the various chambers.
The wylde that rra and other builders use safely shoots both.
Posted by: Hidalgo

Re: 5.56 or 223 - 01/28/09 02:03 PM

But afterwards....did you actually have it "zeroed"? Are you going to hunt with these loads? Before you go hunting, doesn't that practice require another trip to the range and more wasted ammo getting the rifle back to zero with the hunting loads? And after you zero with the hunting loads, do you have to re-zero when you shoot the NATO loads again? (thus wasting even more ammo)

I'm not picking at you Mark, but I shoot as much or more than the "average" guy and I can't honestly think of any instance where shooting NATO ammunition would have saved me any money. Granted, I do reload, and if I didn't I might look at this in a little different light.
Posted by: Evil_Lurker

Re: 5.56 or 223 - 01/28/09 02:07 PM

Quote:

the neck can get pinched
in the throat




The bolt wouldn't go into battery. I'll bet money on it.
Posted by: bigwheeler

Re: 5.56 or 223 - 01/28/09 02:10 PM

Quote:

Quote:

the neck can get pinched
in the throat




The bolt wouldn't go into battery. I'll bet money on it.




You would loose, http://www.winchester.com/lawenforcement/news/newsview.aspx?storyid=11

Keep shooting them and eventually you may have the opportunity to join the broken bolt club.
Posted by: FALFire

Re: 5.56 or 223 - 01/28/09 02:31 PM

Read the first line in the description, it states "The cartridge casings for both calibers have basically the same length and exterior dimensions."

So how could it be possible for a case neck to get pinched in the throat or leade of the chamber. Makes no sense to me.

No where in this article does it state that the case neck can be pinched.

Plus the word "MAY" gets used here twice which to me, means it's possible due to the many number of chambers out there and they don't want to take any chances. Better safe than sorry for them.

Here is the article in full.



Law Enforcement News and Press Releases Details


News and Press Releases

.223 Rem VS 5.56mm

Paul Nowak
5/4/2001
.223 Rem VS 5.56mm

There are a lot of questions about these two cartridges. Many people think they are identical - merely different designations for commercial and military. The truth is that, although somewhat similar, they are not the same and you should know the differences before buying either cartridge.


The cartridge casings for both calibers have basically the same length and exterior dimensions.
The 5.56 round, loaded to Military Specification, typically has higher velocity and chamber pressure than the .223 Rem.
The 5.56 cartridge case may have thicker walls, and a thicker head, for extra strength. This better contains the higher chamber pressure. However, a thicker case reduces powder capacity, which is of concern to the reloader.
The 5.56mm and .223 Rem chambers are nearly identical. The difference is in the "Leade". Leade is defined as the portion of the barrel directly in front of the chamber where the rifling has been conically removed to allow room for the seated bullet. It is also more commonly known as the throat. Leade in a .223 Rem chamber is usually .085". In a 5.56mm chamber the leade is typically .162", or almost twice as much as in the 223 Rem chamber.
You can fire .223 Rem cartridges in 5.56mm chambers with this longer leade, but you will generally have a slight loss in accuracy and velocity over firing the .223 round in the chamber with the shorter leade it was designed for.
Problems may occur when firing the higher-pressure 5.56mm cartridge in a .223 chamber with its much shorter leade. It is generally known that shortening the leade can dramatically increase chamber pressure. In some cases, this higher pressure could result in primer pocket gas leaks, blown cartridge case heads and gun functioning issues.
The 5.56mm military cartridge fired in a .223 Rem chamber is considered by SAAMI (Small Arm and Ammunition Manufacturers Institute) to be an unsafe ammunition combination.


Before buying either of these two types of ammunition, always check your gun to find what caliber it is chambered for, then buy the appropriate ammunition. Most 5.56mm rounds made have full metal jacket bullets. Performance bullets - soft points, hollow points, Ballistic Silvertips, etc. - are loaded in .223 Rem cartridges. Firing a .223 Rem cartridge in a 5.56mm-chambered gun is safe and merely gives you slightly reduced velocity and accuracy. However we do not recommend, nor does SAAMI recommend, firing a 5.56mm cartridge in a gun chambered for the .223 Rem as the shorter leade can cause pressure-related problems.

Winchester Law Enforcement Ammunition
Posted by: Evil_Lurker

Re: 5.56 or 223 - 01/28/09 02:48 PM

I didn't see anything in there about pinching a case neck . Did you?

Quote:

Keep shooting them and eventually you may have the opportunity to join the broken bolt club.





I never said I shot them in my AR, I use .223 Rem.
Would I be afraid to shoot them? No.
I've got a full bull barrel, and the bolt has been tested to 5.56 proof round standards, so the chances of "breaking" a bolt (I assume the locking lugs would shear first, eh?) is a pretty remote possibility.
Like I said, in a .223 bolt, pump or lever action rifle, the warning should be heeded. They may have been designed to only handle .223 Rem pressures, and they don't proof test them to 5.56 NATO standards.

Winchester does not produce an AR, which could explain their take on the subject.

I've shot a lot of 5.56 NATO through my Mini-14s, though, which are marked .223 Rem. and they aren't showing any ill effects. Never had any kind of malfunction, either. I have serious doubts their bolt design is any stronger than an AR, and the breech isn't any bigger.

Go figure, huh?
Posted by: bhk

Re: 5.56 or 223 - 01/28/09 04:31 PM

Although Mini-14 are marked .223, they really have a 5.56 chamber. The manual that comes with the gun indicates it is safe to fire both. I think marking them a .223 is a 'political correct' tactic on their part. They don't want anyone to think they are making assault rifles.
Posted by: ghjacobs

Re: 5.56 or 223 - 01/28/09 05:55 PM

All this 223 vs. 5.56 started in the 80's when the goverment tried to makr the 5.56 a long range gun. Before that military ammo had 55 grain bullets. Back in the 60 when Remington brought out the 223 they used the specs for the 5.56 with a 55 grain bullet. The old gov. m16 had a 1-12 twist barrel also. In the 80's the went to the 69 grain bullet they use today. That's when they went to the 1-9 twist barrel they also incresed the thoart length. Also up the pressures to get the vel. up. So this all means that the 223 vs the 5.46 is the same just a differnet bullet. Since most chambers are way longer than ecs SAMI specs anyway the firing of 5.56 in a 223 chamber should be just fine. Unless you have a custom gun with a short thoart.
Posted by: bigwheeler

Re: 5.56 or 223 - 01/28/09 07:34 PM

The freebore diameter in a reamer for .223 is .2240 to .2245 in the various chamberings. In a 5.56 JGS , PTG nato it is .2265 in a clymer nato it is .2270.
The case mouth diameter is as low as .2510 in a remington match chamber
while the nato chamberings are .2540 and 2550. You can see with thicker brass
and smaller neck and throat openings how the problem can arise.
Posted by: bobeano

Re: 5.56 or 223 - 01/30/09 07:50 PM

so when you get a box that says 223/5.56
what are you getting
Posted by: NM Leon

Re: 5.56 or 223 - 01/30/09 08:29 PM

Many thousands (millions) of mil-surp rounds have been fired out of .223 chambered ARs with no ill effects. That's reality.

I read somewhere long ago that the problem is more likely to occur in NATO ammo made in other countries as apparently not all are the same.

Having said that, SAAMI says don't do it http://www.saami.org/Unsafe_Combinations.cfm. , and I agree with Hidalgo. If I was a full auto guy I would probably feel differently, but I don't see much advantage to using mil-surp ammo and definitely see some downside.