5.56mm is not 223?

[harmonic]

If a S&W M&P 15 Performance Center is marked 5.56mm, does that mean it can't digest 223 ammo? And can anybody recommend instructional material for cleaning and maintenance?

thanx

 

[bang_bang]

From my understanding a rifle marked 5.56 will shoot both 5.56 ammo and .223 Rem.

One marked only for .223 Rem will not shoot 5.56 ammo.

Please correct me if I'm wrong.

 

[atlanticfire]

If its marked 5.56 you can shoot both. If its marked 223 than its ONLY 223.

 

[yenchisks]

whats the difference?

 

[harmonic]

thanx guys. It's a pleasure doing business with you.

 

[bang_bang]

Difference between them is a slight case sizing on one of the 2, my guess would be the military 5.56 casing.

I heard that this small difference will make the casing jam in the rifle.

 

[cbrgator]

You CAN shoot .223 in a 5.56 chamber with no problems. You CANNOT shoot 5.56 in a .223. The difference is that 5.56 has thicker brass and the precise dimensions of a .223 chamber will likely cause the gun to malfunction.

yenchisks, the difference is that in addition to the thicker brass, 5.56 is also loaded to higher pressures. This is to compensate for the fact that the thicker brass allows less capacity for powder.

 

[woodfiend]

5.56 is military, and .223 is civilian. They both have the same dimensions, but 5.56 is loaded hotter and has a thicker case. 5.56 usually has regulations regarding velocity, and other small things that have a minimum standard. .223 usually shoots about 200 feet per second or so slower than 5.56.

 

[ugaarguy]

Chambers Are Different

5.56 NATO has a thicker case web, and is loaded to higher pressure than .223 Rem. 5.56 NATO chambers are a bit looser (longer headspace) than .223 chambers. Also, the barrel leade to the threads is longer, and at a shallower angle in a 5.56 chamber vs. a .223 chamber. When 5.56 ammo is used in a .223 chamber the tighter headspace and shorter, steeper leade will further increase the overpressure situation.

More info here - http://ammo.ar15.com/ammo/project/hist_diff.html

 

[HorseSoldier]

This question comes up often enough that there should be a sticky up at the top of the Rifle Country section explaining this and 7.62x51 vs 308.

 

[yenchisks]

Well thanks, I did'nt no that.I guess you can teach a old dog.

 

[BHP FAN]

That's not really the answer,though.Some guns [my Mini-14 for example] will gobble either one without showing a preference.Boltys tend to be more finicky,though I've only had problems with reloads,not factory ammo.As to the difference in velocity ,200fps is exactly one half of a Daisy Red Ryder BB gun's worth of difference.That being said,you should always use the right ammo in the right gun.[obligatory lawyer type CYA phrase has been invoked...] so,YMMV.

 

[ugaarguy]

That's not really the answer,though.Some guns [my Mini-14 for example] will gobble either one without showing a preference.

It is the answer, because the ammo and chamber specs are different. I suppose SAAMI just doesn't know what they're talking about though.

Per SAAMI - http://www.saami.org/Unsafe_Combinations.cfm

CENTERFIRE RIFLE​

In Rifle Chambered For​

Do Not Use These Cartridges​

223 Remington​

5.56mm Military

222 Remington

30 Carbine​

 

[WardenWolf]

It's not always true. Many manufacturers will label a 5.56-compatible gun as a .223 because it makes it seem less evil to anti-gun people because it doesn't fire a "military round". Ruger has confirmed that their Mini-14's are, in fact, rated for 5.56 cartridges. It just does not market them as such. If in doubt, call the manufacturer and ask them over the phone if it is safe to use 5.56. They will usually tell you.

 

[sargenv]

Actually, your Mini-14 will not eat both of them.. at least not for long. I had a Mini-14 that I fed a good diet of 5.56 ammo through. It ate up the action and spit it out. One day it stopped working. It was cost prohibitive to fix it. You should only use ammo type .223 remington just like your manual tells you to, or one day it will stop working like mine did.

 

[janobles14]

the difference has to do with throat length more than anything else. you CAN actually shoot either round in any rifle (yes even the .223 chambered ones) but you will probably encounter pressure issues with anything but the bare minimum of loads (shooting 5.56 out of a .223 weapon.). the 5.56 is made for longer bullets (hence the longer throat issue). just stick with what these guys said and youll be fine.

 

[X-Rap]

Somebody forgot to tell my guns I have AR uppers in DPMS, FN, and Colt as well as a few bolts and they all shoot the same ammo seamlessly.
LC in all the .223 + .223 in all the 556. On top of that I reload them all the same and nobody got hurt.
Is it the same for 7.62 and 308? Heaven help me if it is.

 

[hso]

From nationmaster.com.

5.56 mm NATO versus .223 Remington

While the 5.56 mm and .223 cartridges are very similar, they are not identical. Military cases are made from thicker brass than commercial cases, which reduces the powder capacity (an important consideration for handloaders), and the NATO specification allows a higher chamber pressure. The 5.56 mm chambering, known as a NATO or mil-spec chambers, have a longer leade, which is the distance between the mouth of the cartridge and the point at which the rifling engages the bullet. The .223 chambering, known as SAAMI chamber, is allowed to have a shorter leade, and is only required to be proof tested to the lower SAAMI chamber pressure. To address these issues, various proprietary chambers exist, such as the Wylde chamber (Rock River Arms)[1] or the Armalite chamber, which are designed to handle both 5.56 mm and .223 equally well. Handloading is the process used to create firearm cartridges by hand versus those put together en masse and sold commercially, generally in packages of 6 to 50. ... Saami or SAAMI can stand for: Sami peoples Sporting Arms and Ammunition Manufacturers Institute This is a disambiguation page — a navigational aid which lists other pages that might otherwise share the same title. ... A proof test is a test wherein a deliberately overpressure round is fired from a firearm in order to verify that the firearm is not defective and will not explode on firing. ... ArmaLite, originally the ArmaLite Division of the Fairchild Engine and Airplane Corporation, is one of the most influential corporations in the history of 20th century small arms. ...


Using commercial .223 cartridges in a 5.56-chambered rifle should work reliably, but generally will not be as accurate as when fired from a .223-chambered gun due to the excessive lead.[2] Using 5.56 mil-spec cartridges (such as the M855) in a .223-chambered rifle can lead to excessive wear and stress on the rifle and even be unsafe, and the SAAMI recommends against the practice.[3] Some commercial rifles marked as ".223 Remington" are in fact suited for 5.56 mm, such as many commercial AR-15 variants and the Ruger Mini-14, but the manufacturer should always be consulted to verify that this is acceptable before attempting it, and signs of excessive pressure (such as flattening or gas staining of the primers) should be looked for in the initial testing with 5.56 mm ammunition.[4] Mini-14 Ranch Rifle (note folding leaf rear sight) with flush 5 round magazine The Mini-14 is a small, lightweight semi-automatic rifle manufactured by Sturm, Ruger. ...

 

[WardenWolf]

Actually, your Mini-14 will not eat both of them.. at least not for long. I had a Mini-14 that I fed a good diet of 5.56 ammo through. It ate up the action and spit it out. One day it stopped working. It was cost prohibitive to fix it. You should only use ammo type .223 remington just like your manual tells you to, or one day it will stop working like mine did.

That may have been one of the older ones. Ruger has made a number of design changes since it was first introduced, and the newer ones are a bit more robust.

 

[harmonic]

Using commercial .223 cartridges in a 5.56-chambered rifle should work reliably, but generally will not be as accurate as when fired from a .223-chambered gun due to the excessive lead

Thanx HSO. But where does one find 5.56 brass? None of my typical haunts catalogues it as such.

 

[janobles14]

once fired lake city can be found TONS of places!

 

[X-Rap]

My intent was not to sway people to stray from safe firearm practice but rather lay some fears aside as to what I have seen personally. I can also state that I have seen and know others who have mixed brass and shot in various rifles without problem.
Here comes the CYA clause. Work up your loads carefully and make these choices using your own data and experience.

 

[WardenWolf]

Some can handle it better than others. Take the Saiga .223, for instance, where everything except the bolt and the barrel's internal diameter (external is the same) are the same as the 7.62x39 version. It's so overbuilt and has so much extra material, there should be no way the 5.56's pressure could hurt it. But then again, do I fire 5.56 through mine? No. Am I confident it could eat it 100% reliably if it had to? Yes. I do not endorse or recommend putting 5.56 through ANY gun not specifically labeled for it without first consulting the manufacturer.

 

[elmerfudd]

I've put a fair amount of 5.56 through my Saiga .223. No problems so far.

 

[JonB]

So does this mean one should not use Lake City brass to reload for a .223?

My AR is marked 5.56 so I don't care what I feed it. But I've had my eye on a Savage 12BVSS which is .223.

I reload for my AR using .223 load data (24gr of H335) and .223 dies but most of my brass is LC. Would I need to buy some .223 marked brass for the Savage?