223 and 5.56 labelling

[jim243]

This raises more questions than it answers.

1. Why is there two sets of dimensions so close to each other?
2. Which is the better round to use? 223 in bolt and 5.56 in AR?
3. What is the accuracy difference?
4. Why is there no dies for 5.56 for purchase?
5. Since it takes more work by the mfg to make 5.56 shouldn't surplus ammo cost more than 223? (brass not steel)
6. How much longer or shorter is barrel life using one or the other?

Jim

 

[MrDig]

This raises more questions than it answers.
1. Why is there two sets of dimensions so close to each other?
Jim

Why is a bathroom called a Latrine or a Head in the Military? Why is a hat called a Cover?
5.56x45 is the Military designation for .223 Remington. Like Commode is the military designation for a Toilet.

 

[allaroundhunter]

5.56x45 is the Military designation for .223 Remington. Like Commode is the military designation for a Toilet.

MrDig, there ARE differences between the two. That is why some manufacturers recommend against using 5.56 in their .223 rifles...It is not just the metric vs. standard measurements. Go back and read post #15, rc explains the differences.

 

[allaroundhunter]

1. Why is there two sets of dimensions so close to each other?

Again, rc explains it in post #15:

a longer chamber leade to handle long military tracer ammo.

 

[303tom]

I have a couple of buddies who work at Lake City & they say they run .223 on the same line as the 5.56 NATO............

 

[The Real Wyatt]

Weird Al yankovitch did a cover of Michael Jackson's "Beat It" titled "Eat It". My recommendation isto just "Shoot It".

Much ado about nothing.

Move along folks ... nothing to see here.

 

[allaroundhunter]

I have a couple of buddies who work at Lake City & they say they run .223 on the same line as the 5.56 NATO............

As well they should. The difference is going to come from the longer tracer rounds. It doesn't require different machinery to make 5.56, just a longer throat than Match Grade .223 rifles are made to handle......this really is not a hard concept

 

[jim243]

5.56x45 is the Military designation for .223 Remington

I don't think so, which came first the 5.56 or the .223, I believe it was the 5.56 so why make a .223???

9mm is 9mm no matter what, so why is 5.56 mm a .223???

And you can't say it was because of NATO since the M-14 was a .308 before it became a 7.62 NATO round (same dimentions).
why a difference in 5.56 and .223???

Jim

 

[jmr40]

Looking at my reloading manuals they show various 30-06 loads ranging from 23,000 PSI up to 60,000 PSI. I own 6 different rifles in 30-06. When reloading they all have different chambers and throats. Bullets seated too far out will load and shoot fine in some guns and not in others. Velocities vary by as much as 50 fps with ammo from the same box which proves that some guns are shooting at higher pressures than others. This is normal.

Despite all the internet gak the 223 and 5.56 are essentially interchangeable. Just like the wildly differing chamber pressures and throat lengths in 30-06 rifles there may be minor differences between different 223 and 5.56 chambered rifles. For all the talk no one has ever presented an example of it ever causing a problem. Most all guns and even ammo now has both 223 and 5.56 stamped on them. Probably 90% of all shooters are unaware of the internet controversey and have been happily using the 2 interchangeably for years with no problems.

I don't have a link to back it up, but on another of these debates someone claimed that SAAMI specs were now officially calling the 2 one and the same. If true, I'd like to see confirmation. It should end the controversy, but probably wouldn't.

 

[allaroundhunter]

Despite all the internet gak the 223 and 5.56 are essentially interchangeable. Just like the wildly differing chamber pressures and throat lengths in 30-06 rifles there may be minor differences between different 223 and 5.56 chambered rifles.

A rifle chambered for .30-06 is designed to handle the longest throat length and highest pressure associated with a .30-06 round.

A match grade .223 rifle is designed to handle the throat length of the .223 round to maximize its accuracy. Since the 5.56x45 and .223 have different throat lengths, this is where the danger can arise.

As rc said, most modern rifles chambered for ".223 Rem" should be able to handle 5.56 just fine because manufacturers know that if they made them all to the tightest .223 tolerance there would be more accidents.

I don't have a link to back it up, but on another of these debates someone claimed that SAAMI specs were now officially calling the 2 one and the same. If true, I'd like to see confirmation. It should end the controversy, but probably wouldn't.

SAAMI still recommends against firing 5.56x45 in a gun chambered for .223 Rem. Even if it doesn't cause a bad failure, it does cause extra wear on the gun that can lead to problems.

Almost a quarter of a century ago, SAAMI recognized potential problems with shooters assuming that the 5.56mm cartridge was identical to the commercially available .223 Remington round. Here is their 31 January 1979 release, with some minor errors corrected:

"With the appearance of full metal jacket military 5.56 ammunition on the commercial Market, it has come to the attention of the Sporting Arms and Ammunition Manufacturers' Institute (SAAMI) that the use of military 5.56mm ammunition in sporting rifles chambered for Caliber .223 Remington cartridges can lead to higher-than-normal chamber pressures and possible hazards for the firearm, its user and bystanders.

Tests have confirmed that chamber pressures in a sporting rifle may be significantly higher in the same gun when using military 5.56mm ammunition rather than commercially loaded Caliber .223 Remington cartridges, according to SAAMI.

SAAMI points out that chambers for military rifles have a different throat configuration than chambers for sporting firearms which, together with the full metal jacket of the military projectile, may account for the higher pressures which result when military ammunition is fired in a sporting chamber.

SAAMI recommends that a firearm be fired only with the cartridge for which it is specifically chambered by the manufacturer."

That quote taken from thegunzone.com

 

[awgrizzly]

Look folks, the .223 Remington and the 5.56x45 NATO are basically the same cartridge, although some have said the NATO has thicker walls. I personally doubt it, if they do I doubt it makes a spit of difference, but I don't know and I'm too lazy to find out. Suffice it to say I shoot 5.56, but no big deal in that since all my ARs have 5.56 chambers. There may be a difference in loading however, since I read that some NATO are loaded for 3200fps. I don't know, nor care that much... just saying. I don't care because the guns I use are built to the specs of the M16, and since I've never seen the battlefield littered with the bodies of soldiers who's gun exploded I feel secure.

The difference between the two is not in the cartridge but in the chamber. The .223 was designed to have a shorter lead, the distance between the throat and the beginning of the rifling, simply because it's felt that this provides a more accurate rifle. No other differences, like tighter tolerances, matter. The 5.56 was designed with longer leads because they apparently need it for tracers, and since the M16 is an intermediate range weapon accuracy isn't that critical.

On the longer bullet and lead issue... I've not measured the magazine but by eyeball I can't see how a bullet can be much longer than the .223 spec (2.26") because it won't fit in the magazine. I've heard that folks who shoot extra long ammo in competition have to feed the cartridges by hand as they won't fit in the magazine, but these folks pretty much know what they're doing. There's little extra space. When I load 5.56 ammo, the longer bullets, like the 62 grain, have to be seated deeper. Though this can cause greater pressures, it's made up for in the recommended powder load. I think of greater concern than the gun blowing up because you shot 5.56 in a .223 is the potential issue of timing where differences in pressure and burn rate can cause the semi-auto rifle not to cycle properly... shot stroking.

There is a lot of blabber about these things that is exaggerated or blatantly hog wash, but I suspect experts generally avoid setting this straight due to liability concerns. better to just say don't shoot 5.56 in a .223. If your gun blows up it probably was caused by something other than a 5.56... but then what do I know. Folks like RC are who you should listen to, but he already spoke and you're still talking about it.

 

[Hypnogator]

OK, I'll weigh in with my understanding of the difference in the calibers: The specifications for the 5.56mm chamber are a bit looser than for .223, although they nominally are the same cartridge. SOME 5.56mm cartridges that barely meet military specs are a bit long for the commercial .223 chamber.

The result is, that most mil-spec .556 ammo will shoot fine in a .223 chamber, but some produced within tolerance of the .556 but with slightly oversized cases can cause problems. If the cases are at the max spec for diameter, they won't chamber properly in a .223, but if they are at the max spec for length they will chamber, but the mouth of the case jams into the back of the rifling, causing it to grip the bullet tighter and consequently raise chamber pressures, sometimes astronomically.

Target shooters prefer .223 chambers because they're more accurate. MILSPEC .556 chambers are slightly larger which result in poorer accuracy but much greater reliability. My AR-15s are both chambered for .223 Wilde, which has the .223 spec for chamber diameter, but with a slightly longer throat so that 5.56mm ammo won't jam into the rifling. It's almost as accurate as a .223 target chamber, and almost as reliable as a 5.56 chamber.

 

[roadchoad]

5.56 and .223 don't really have a huge pressure difference, it's just the differences in measurement methods that make it look as such.

So, based on all that chamber/leade info, seems to me that any 55gr 5.56 should work in a .223, since the bullet won't be any longer than .223 round, and can't cause a pressure spike. Go look at pics of different varieties of M855, M856, M193, etc. The loaded cases are all the same length. It would have to be the reduced case volume due to the fact that a longer bullet must be deeper seated in the case, and the additional rifling contact surface of the longer bullet that contribute to higher pressure.

What is the average bullet weight for a .223? Aren't there long 70 grainers out there, that would also exhibit this same situation??

All this discussion seems purely academic. I have seen no reports of actual failure whenever this topic comes up. If anyone can point to one, it would lend some credibility to this debate, or at least one side of it.

 

[awgrizzly]

OK, I'll weigh in with my understanding of the difference in the calibers: The specifications for the 5.56mm chamber are a bit looser than for .223, although they nominally are the same cartridge. SOME 5.56mm cartridges that barely meet military specs are a bit long for the commercial .223 chamber.

The result is, that most mil-spec .556 ammo will shoot fine in a .223 chamber, but some produced within tolerance of the .556 but with slightly oversized cases can cause problems. If the cases are at the max spec for diameter, they won't chamber properly in a .223, but if they are at the max spec for length they will chamber, but the mouth of the case jams into the back of the rifling, causing it to grip the bullet tighter and consequently raise chamber pressures, sometimes astronomically.

Target shooters prefer .223 chambers because they're more accurate. MILSPEC .556 chambers are slightly larger which result in poorer accuracy but much greater reliability. My AR-15s are both chambered for .223 Wilde, which has the .223 spec for chamber diameter, but with a slightly longer throat so that 5.56mm ammo won't jam into the rifling. It's almost as accurate as a .223 target chamber, and almost as reliable as a 5.56 chamber.

No no no, I'm sorry but that's full of errors, even wreckless. The case is not too large for the chamber. The mouth of the case does not jam into the back of the rifling and grip the bullet tighter... that's actually very silly... do you have any idea how long the neck would have to be to do this? I doubt if there is a problem with loose military specs. Any greater looseness in chamber diameter due to loose military specs would not present a danger.

The only issue would be that the bullet (meaning the lead projectile with a point in front) may jam into the back of the rifling in a .223. But even that may not be true, because technical theory and reality are often quite different. Bear in mind that the maximum overall length for the 5.56 cartridge is exactly the same as a .223 Remington. The larger bullet would have to be seated deeper and if the powder charge wasn't tuned to this it could cause high pressures. People would probably only face this in hand loaded ammo.

 

[awgrizzly]

5.56 and .223 don't really have a huge pressure difference, it's just the differences in measurement methods that make it look as such.

So, based on all that chamber/leade info, seems to me that any 55gr 5.56 should work in a .223, since the bullet won't be any longer than .223 round, and can't cause a pressure spike. Go look at pics of different varieties of M855, M856, M193, etc. The loaded cases are all the same length. It would have to be the reduced case volume due to the fact that a longer bullet must be deeper seated in the case, and the additional rifling contact surface of the longer bullet that contribute to higher pressure.

What is the average bullet weight for a .223? Aren't there long 70 grainers out there, that would also exhibit this same situation??

All this discussion seems purely academic. I have seen no reports of actual failure whenever this topic comes up. If anyone can point to one, it would lend some credibility to this debate, or at least one side of it.

Thank you, common sense alone dictates this to be true. What you say about reduced case space is correct. I decided to load some 55gr Hornady VMax recently using the same powder load as my FMJBTs. It wasn't until I seated the bullets that I realized how much longer they are due to the plastic insert. As a result I had to seat them so much deeper I have real misgivings about using them. I'm waiting for the snow to melt at the range to test a couple (it's a relatively tame load). Perhaps I should enlist the aid of someone I don't like to shoot the first round!

One has only drop a round into the magazine and look at how much space there is in front of the bullet. It should be nearly impossible to get bullets too long for the lead on a .223 unless they are hand fed. But perhaps the diameter of the rounded bullet taper might be a factor.

 

[303tom]

Time for some more pictures...........

 

[dprice3844444]

nobody will ever notice it from brooklyn,just shoot it

 

[roadchoad]

For fun, I did search for 5.56, .223, and kaboom, explosion, or failure. I noticed a lot of bad .223 ammunition causing failures in both .223 and 5.56 guns, and some 5.56 failures in 5.56 guns, but no 5.56 in .223 failures. Judging by that, I'd say you are more likely to blow up a gun by getting a bad batch of ammo than shooting 5.56 in a .223. Like all things, use your own judgement and don't believe everything you read on the internet.

EDIT: I have since found a single case of 5.56 in a .223 failing. Ironically, these are all AR type rifles.

 

[montveil]

interesting from H&R

I called H&R and they told me NO 5.56.
BUT my 1 in 9 twist 223 will shoot better with heavier bullets between 62 and 77 grains.
I found that interesting and the previous discussion about heavier bullets being longer does not seem to apply.
Seeing there ARE differences between the 223 and 5,56 and almost all manufacturers so no to 5.56 in a 233 chamber, I'll stick to the 223
Thanks for all the replies

 

[alsaqr]

There is a popular myth that the leade of the 5.56mm chamber is longer because the tracer bullet is longer. Yep, the tracer bullet is longer than the ball bullet but it protrudes no further from the case. Recently a "gun expert" at Rifle Shooter magazine made the statement that the tracer bullet is "almost twice as long" as the ball bullet. Well its not.

http://img208.imageshack.us/img208/4615/dsc01331r.jpg

 

[alsaqr]

There are popular SAAMI myths out there:

Myth: US military 5.56mm cases are thicker than commercial cases. Go to Tech, then go to .233 brass weights comparison.

http://ar15barrels.com/tech.shtml

There are at least 10-12 different .223/5.56mm chambers; some are listed here. Go to Tech, then go to Detailed .223 vs 5.56mm reamer.......

http://ar15barrels.com/tech.shtml

A local gunsmith tells me that no current maker produces what it known as a "SAAMI chamber".

 

[roadchoad]

Shot my .223 handi for the first time today, just 4 times since my son and my brother's fiance didn't like the louder guns and they wanted to shoot the 9mm carbine. The two .223 Winchester (3600fps varmint stuff) 45gr factory shells had flattened primers. The two 5.56x45 55gr M193 Malaysian had no signs of high pressure. Take from that what you will.