5.56 vs .223

[FyredUp]

Okay, can someone please clear this up for me once and for all?

.223 can be fired in a rifle that is made to fire 5.56mm? But 5.56mm isn't supposed to be fired in a rifle made to fire .223?

Is the Ruger Mini-14 capable of firing 5.56mm?

Thanks for the help.

[crghss]

Nothing to clear up

[olyinaz]

Winchester white box is available in both. The cases dimensions are exactly the same size but 5.56mm NATO has slightly higher maximum pressure allowed than .223 Remington (and by that I mean VERY slightly). WWB, for example, lists 50fps difference in the two loads. [PFFT] That's it!

So yes, the Mini-14 can handle 5.56mm without issue and mine has ingested and spit out thousands of rounds of 5.56mm ball ammo. Now as for accuracy that's a different story! You may find that 5.56mm doesn't shoot worth a darn in your rifle (it certainly doesn't in most of mine) and patterns more than it groups. Not a huge problem for plinking, but very unhelpful if you're actually trying to hit something.

Regards,
Oly

[Brian Pfleuger]

Originally Posted by crghss

Nothing to clear up

Uh, no. No, no, no.

From Winchester:
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.

[drjjpdc]

The old standard advice about using what's written on the barrel usually works for me.

[brian923]

they are NOT the same. if you reload, 5.56 brass is thicker, therfore, has less case volume capacity. when a powder bullet combo works for a .223, and is close to max. the same combo in NATO brass can become very dangerous. use only .223 unless you barrel, NOT THE STOCK, NOR THE RECIEVER. only the BARREL should be trusted with which ammo to use. if it says 5.56, then you can shoot both. if the barrel says nothing, have a smith look at it. its not worth losing you hand or your face for 35 bucks.

and to pressures only being a little different........ what are you talking about!!!!!!

.223 remington, sammi spec 55,000 psi
5.56 NATO 62,366 psi

that an amazing differeance!! 7,000 psi is nothing to scoff at. that 7,000 psi can really ruin you rifle and your day. when reading a reloading manual, 7,000 psi can be the differeance between a mild load, and a blown barrel. check it out, search reloading mishaps, or reloading problems. youll see what these pressures can do to a gun. it litterally blows them apart!

[sneaky pete]

old Sneaky Pete here: Does anyone "Honestly" have a count on how many times this topic has been argued over the past 10 years???? My advise--If you feel like firing a 5.56 in a .223Rem chamber--Go for It! If you don't then don't--I've been firing "Mil-Issue"-like out of my arms room- 5.56 NATO in my 1973 Colt SP-1 for over 20 years--NO-PROBLEMS, but then maybe "Your" rifle might Blow-Up--who knows???? Generally M-16 Chambers have Longer Throats then AR-15s and that is because of "Full Auto" fire and that's the diference. OBTW-- My handloads chronograph faseter than the Mil-issue 5.56NATO which mean Higher Preasure in my .223Rem chamber. Maybe I've got a Magic Rifle?? SNEAKY PETE

[blume357]

you can shoot 5.56 nato in a Ruger mini-14... the factory says it's okay.

I can't speak for other rifles.

[crghss]

I've been firing every 5.56 round I could find over the years in my Mini-14 until I got ride of it last year. The people I shoot with do the same in Rem 700, AR's and the like.

If you don't feel comfortable doing it then don't. I haven't had a problem.

[JWT]

I've always read you can fire a .223 in a gun chambered for 5.56 but should not fire a 5.56 in a gun chambered for .223. Read the instruction book that came with your particular gun and go with their advice.

[Come and take it.]

I talked to a retired Air force man ( my father in law) He worked in spec ops during Vietnam.

I was going shooting the other day with my 220 swift. Pulled the shell out to show it to him.

He said that it reminded him of the TWO-TWO-THREE he used in his M16.

After he left the air force he wouldnt have anything to do with guns. His knowledge of sporting arms is limited.

For him it was common terminology at the time to call the cartridge TWO-TWO-THREE

Interesting to say the least.

[Brian Pfleuger]

Originally Posted by crghss

Sorry I mentioned it.

I've been firing every 5.56 round I could find over the years in my Mini-14 until I got ride of it last year. The people I shoot with do the same in Rem 700, AR's and the like.

If you don't feel comfortable doing it then don't. I haven't had a problem.

That's fine.... and qualified information.... but it's entirely different than "They're one and the same. Nothing to clear up." Which is both technically incorrect and potentially dangerous.

[sneaky pete]

Sneaky Pete back---Can anyone explain to me why my Colt SP-1 after firing 5.56NATO @ 62,366 PSI ( as issued by my arms room) for over 20 years in a .223Rem chamber(rated @ 55,000 PSI-by SAAMI) hasn't blown up yet????--Does anyone think that possbly the "Design Engineers" posibly built a "Safety Factor" into the design???? And Don't forget about the "Lawyer-Factor--ie Liability" S/P

[Brian Pfleuger]

Can anyone explain to me why my Colt SP-1 after firing 5.56NATO @ 62,366 PSI ( as issued by my arms room) for over 20 years in a .223Rem chamber(rated @ 55,000 PSI-by SAAMI) hasn't blown up yet????

Well, your gun could be one with a longer throat than is typical of 223. Your gun may be built stronger by design or just sheer luck. There's also the likelihood that 5.56 is not all loaded to max pressure. My understanding is that there is approximately a 10% "safety margin" and then an additional margin before gun failure. If that's true, then you're running more than 1800 psi into the margin between "safety" and failure. How big is that margin?

Do what you want with your own gun.... and you're own hands and face, but telling others to do the same should come with a disclaimer, at the very least.

[Edward429451]

Ruger Mini 14 chambers have always been mil spec. Even if they are marked 223, call em and ask, I did. It's the bolt guns that are 223 and shouldnt take the mil spec ammo.

[tju1973]

I alsways was hung up wanting a 5.56 until I actually looked at gunshops locally and box stores-- almost always there is no 5.56 to be found-- .223 is abundant as heck though-- that being said, most good ARs (and the Mini 14 always) have 5.56 chambers, so you are ok with either. Unless you get a killer deal on a pallet of 5.56 that "fell off the truck", you probably are better served by just getting .223..IMHO...

[koolminx]

I really don't get it why questions like this pop up all the time...

A .223 will shoot .223 ammo, and a 5.56 shoots 5.56 ammo, and a 30/30 shoots 30-30 ammo, and right on down the scale.

Why would someone want to shoot something that was NOT made for their particular gun? This just astounds me... Is it so you can pick up downed enemies ammo and continue the good fight? I am really stumped.

I never understood the need to shoot .38 through a .357 either... Or which ever direction that went...

Why is there a need to do this? Please explain

[Brian Pfleuger]

Why would someone want to shoot something that was NOT made for their particular gun? This just astounds me... Is it so you can pick up downed enemies ammo and continue the good fight? I am really stumped.

I never understood the need to shoot .38 through a .357 either... Or which ever direction that went...

Why is there a need to do this? Please explain

It's called money. 5.56 military surplus ammo can be had for fractions of the price of 223.

38 in a 357? Let's see.... cheaper, less recoil, quieter practice, all in a gun that can handle much more power should the need arise. The guns are essentially designed to be interchangeable between 38sp and 357mag. That's a whole different world. Much like shooting 9mm in a gun designed for 9mm NATO spec ammo. No problem, everything is fine. On the flip side, some 9mm guns cannot handle 9mm NATO pressures and some can. Just like 5.56 and 223, telling someone "Go ahead! I do it all the time!" is dangerous.

[handlerer]

Higher pressure doesn't necessarily mean higher energy. A smaller case capacity must function at a higher pressure to achieve the same MV. The 223 case is thinner and accommodates a larger powder charge at lower pressure, yet achieves equivalent MV,and ME. I have used both 223 and 556 in my Mini-14 and must caution reloaders about getting the two mixed up. Most 556 will not accept a primer, w/o pocket reaming, but some will, maybe 1 in 10. These ones are not safe, because the primer deformed being seated and with a max load, 69 gr Sierra bt , and a hot h335 load. I popped two primers and the second shell was stuck halfway ejected, with the case rim missing a couple of sections. Luckily I was able to tap the shell out with a rod and after a good cleaning there was no damage, but now I know to do my homework before attempting to reload 223 , and 556 brass. You must keep from getting mixed, and follow instructions carefully, about case preparation.

[ranger dave]

let talk about the 7.62x51mm vs 308 win

[Come and take it.]

It's the bolt guns that are 223 and shouldnt take the mil spec ammo.

Bolt actions are among the strongest actions around. Plus many have ports in the side to bleed off pressure if a case ruptures.

Wouldn't have a problem really hopping up a load for a bolt action as much as I would a semi-automatic.

If the shoe fits, wear it

In this case if the cartridge fits than shoot it

[koolminx]

Thanks for the info Peetzakilla.

Why do people buy pieces they can't afford ammo for? Never mind...

[olyinaz]

Well, I'm sorry fellas but the hoopla just strikes me as baloney given my years of shooting and zero known incidents over it. Can anyone honestly tell me they know (reliably) of anyone, anywhere who has damaged a .223 rifle by shooting 5.56 mil spec ammo out of it? I think it's complete horse manure but, well, that's just my opinion and obviously Winchester has taken the trouble to offer a counter opinion.

I quote from Wikipedia (I know I know, but prove it wrong): "According to the official Commission Internationale Permanente pour l'Epreuve des Armes à Feu Portatives (C.I.P.) guidelines the .223 Remington case can handle up to 430 megapascals (62,366 psi) piezo pressure. In C.I.P. regulated countries every rifle cartridge combo has to be proofed at 125% of this maximum C.I.P. pressure to certify for sale to consumers. This is equal to the NATO maximum service pressure guideline for the 5.56x45mm NATO cartridge."

Heck, throat/leade design isn't even standardized but is a matter of design choice by the given rifle/barrel maker. And lastly, given the state of legal wrangling we are swamped with in the U.S. I have a hard time believing that all of the major manufactures are sending likely grenades out the door by the thousands but whatever - the easy road is not hard to travel in this case given how available .223 ammo is.

The best web page I've found regarding the issue: http://www.thegunzone.com/556v223.html

And look at this. Doggone manufacturers are all over the map on the shape/size of both .223 and 5.56: http://www.ar15barrels.com/data/223-556.pdf

Oly

[csmsss]

I guess I'm with onlyinaz. Can anyone provide a link to a documented example of a rifle chambered in .223 Winchester being damaged by firing 5.56/45mm ammo?

[MLeake]

... it requires following a link contained in the article the first link leads to.

In that monograph, McKee said in no uncertain terms to NOT use 5.56mm in a .223 chambered rifle. He indicated there's a risk of the shorter leade actually grabbing and interfering with the round leaving the cartridge.

I don't know if this has ever happened, but the source you quote is arguing exactly 180 out from your own argument.