Can .223 safely be fired from a 5.56 rifle?

I can never remember which way that whole thing goes. But I'll bet a quick search on the forum might find some answers. This thread subject pops up like every week.

.223 remington can be fired in a 5.56x45 chamber

www.thegunzone.com/556v223.html

yes...

M

.223 Remington is safe in a 5.56 NATO rifle.

The reverse is not recommended because of SAAMI pressure.

mopar92 said:

A gunsmith at a local small town gun store told me the .223 is not good to fire in a 5.56 gun.

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Find a new gunsmith.

^No Doubt!

That is something gunsmiths should know, like .38 Special/.357 Magnum...

Ummm...I fired 5.56 from my Mini 14. I guess that was a bad thing??? It was just one box...nothing blew up.

Mini-14s are okay to shoot 5.56 Nato. The Ruger manual says so...

Even though it says "cal. 223" on the receiver.

Bushmaster and some others used to mark their ARs "556" on the barrel and "cal 223" on the receiver. Now it's "cal. 223-556 Nato" marked on the receiver.

When in doubt about any rifle chambering, contact the manufacturer.

M

Thanks for the info, and for the reminder to break out the manual...I guess there is a reason companies spend months of company time making those. My FiL told me it was ok, I guess I just took his word for it.

M1key said:

Mini-14s are okay to shoot 5.56 Nato. The Ruger manual says so...

Even though it says "cal. 223" on the receiver.

Bushmaster and some others used to mark their ARs "556" on the barrel and "cal 223" on the receiver. Now it's "cal. 223-556 Nato" marked on the receiver.

When in doubt about any rifle chambering, contact the manufacturer.

M

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From what I understand the Target ruger mini is the only one that you should only use true .223 in. Correct me if I'm wrong. All the others are fine with either 5.56 or .223, like 99% of ARs. Some custom/target ones with very close-tolerance chambers are .223 only but as noted, the mfg will be able to tell you for sure.

1KPerDay said:

From what I understand the Target ruger mini is the only one that you should only use true .223 in. Correct me if I'm wrong. All the others are fine with either 5.56 or .223, like 99% of ARs. Some custom/target ones with very close-tolerance chambers are .223 only but as noted, the mfg will be able to tell you for sure.

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I believe you are correct. At least that is what I hear from the Mini-Target owners. Again the owners manual should tell you what is safe to shoot.

M

look at it this way, i always remember which way it goes by thinking in numbers, 556 is a bigger number than 223, so smaller fits bigger but bigger dont fit in smaller, hope thats a simple way to help you remember

In my experience, it's kind of the other way around except safety doesn't have much to do with it. I have a Savage 24 .223 over 12 gauge. 5.56 rounds, even the 'good stuff' like Lake City don't extract, you need to poke them out, and are very inaccurate. .223 rounds are fine.

I might also add that the rifle barrel on the Savage has like a 1:14 or somethinng like that twist. It does not handle rounds over 55 grains well at all; you get a perfecct bullet outline keyhole with 64 grain .223's. But at least they extract

Kurt S. said:

In my experience, it's kind of the other way around except safety doesn't have much to do with it. I have a Savage 24 .223 over 12 gauge. 5.56 rounds, even the 'good stuff' like Lake City don't extract, you need to poke them out, and are very inaccurate. .223 rounds are fine.

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That's what Giterboosted just said. 5.56 ("bigger") don't fit "smaller" (.223 barrels). You likely have a true .223 chamber IMO.

my colt is chambered in .223, barrel in 5.56. and I shoot it all through that thing and it couldn't care less.

It's my understanding that the 5.56 chamber is basically the same as the .223 except the beginning of the rifling is further forward so it can accept longer bullets without getting wedged into the rifling when chambered. I don't know How this would be a problem since mil spec ammo is 55 grain thus making it unlikely that the bullet would extend into the .223 rifling. Seems it would be a problem reloading heavy bullets (ie: 90 grain) for a .223 chamber. The larger issue here is probably that the 5.56 with greater space to the rifling (leade) may be less accurate than the .223 spec chamber.

The 5.56 cases are said to be thicker than the .223 resulting in a smaller case volume and greater pressures when reloaded to .223 specs. This would only be an issue for reloading 5.56 and one could just avoid loading to max specs. I've read that the thicker brass causing greater pressures is just a theory and in practice the difference is insignificant.

The 5.56 cartridge is said to have a thicker base which could cause some head space issues and higher pressures. I've never read that this has been an issue in practice.

The 5.56 spec is said to have loads to a higher pressure than the .223 specs. Here one would need to check with the gun specs to see what the max safe load is and check with the manufacturer to determine whether 5.56 military loads would be safe. I believe most .223 cal rifles are made to safely shoot the 5.56 and even be chambered to 5.56 specs (even if it's not indicated on the gun). It's always a good idea to know your gun, so do a little research.

Mopar, load that thang with either 223 or 556 and shoot heck out of it.


BTW, Saigas are .223 Rem on the receivers and mags, but have 5.56 chambers (it's an import thing, I guess).




M

grizzly - That depends on which military ammunition you are talking about. M193 ball is 55gr (and used 1-14 and then 1-12 rifling in the M16 and M16A1), but SS109/M855 ball is 63gr, and uses 1-7 in the M16A2, A4, all M4 variants, and the M249SAW. This change made the standard ball ammo's impact area match the tracer ammo's impact better than M193 ball does. IOW, they did it mostly to accomodate the SAW.

In DM/SPR rifles, there is also the 75gr OTM bullet, still using the 1-7 rifling, and, so I hear, a different-cut chamber to allow the extra long bullet. So, there you have another military bullet that isn't 55gr.

OP - .223 is perfectly safe in a 5.56x45mm chamber, and should be completely functional. The opposite may not be true. 5.56 SHOULD NOT be fired in .223 Match chambers. Your Colt should have a standard 5.56 chamber.

.223 can be fired safely from a 5.56 NATO chambered rifle. There is some debate on whether it is safe to fire 5.56 NATO from a .223 chambered rifle. But specifically yes a
.223 can be safely fired from your 5.56 NATO chambered rifle.

Some of you folks need to do some real research at the primary source on this subject

What exactly do you mean by that, MW?

I had Jeff Quinn from Gunblast and a service rep from Savage tell me that the .223 Edge/Axis has a Wylde chamber. When I get the chance to get out in the field with a camera I'm going to shoot a whole mess of 'wrong dimension' tracers and steel core out of it just to make all of the 'barrel erosion' and 'grain vs barrel length' haters mad. yeah they gonna be mad.