223rem vs 5.56

[yotesmoker]

Can 5.56 ammo be shot in a savage 24v 223/20 ga rifle?

[dougk]

I would call Savage on that question.  Great question BTW....

[trotterlg]

And Savage will say no, there are no manufactures of sporting rifles that will tell you it is OK to shoot military loads in their rifles.  I would doubt you could tell the difference in which one you shot, however the twist rate in your rifle may not be fast enough to shoot the heavier military bullets well.  Larry

[skarke]

OK, here's the scoop on 5.56 vs 223.

1.  5.56 is a slightly longer case at the neck, sort of like a Wylde
2.  The 5.56 is rated to 60,000 CUP, and uses in its current configuration a 69 gr bullet with a fast twist.  The 223 generally has a shorter neck, closer lands (freebore if you like), and slower twists for lighter 50 or 55 grain bullets
3.  The 223 is a thinner case rated to about 50,000 CUP

There's more, but that should do.  Bottom ine, it's fine to shoot 223 in a 5.56, but the other way around in a tight 223 chamber can be very dangerous, because the case mouth can be pinched by the end of the chamber, causing HUGE pressure problems.

Lots of people say that it is fine to shoot 5.56 in a varmint gun, but with all due repect, they are mistaken.  ESPECIALLY with minimum SAAMI chambers in fine varmint rigs.

[trotterlg]

Don't know where you get your case length info, but from what I find they are the same, personal opinion is that the SAAMI/NATO ratings are like the boogy man, not sure it is true at all.  There are lots of things written on this, but I think they are same-same.  Larry

http://stevespages.com/page8d.htm

[pastorp]

I too believe them to be interchangeable. Same with 30/06 & 308 and their military counterparts.

In the 5.56 lighter weoght bullets are available. Your rifles twist should regulate the bullet weight you use.

As far as longer necks, etc. Thats hog-wash. JMO

Regatds,

[skarke]

http://www.thegunzone.com/556v223.html Has a nice summary, if you are interested.

Guys, please, I respond with all respect and humility, but this is a serious, and seriously dangerous issue.

There are very critical differences in case design and chamber design, and this isn't the first or last time it'll be discussed here.  Just weigh a true 5.56 brass case, then a 223 case.  it becomes real obvious real quick.  COAL is another.  Take your garden variety 223 55gr remington psp, measure it.  Then measure a 5.56 69 gr steel point, that's called a need for additional leade 

It is true, however, that current case externals are now identical, and case length at the throat does not appear to be a current problem, so I humbly retract that one portion of my comment.

BUT, case design, pressures, leades in military vs civilian guns, and many other characteristics are importantly different.

SAAMI does still list 5.56 in a 223 chamber as a "do not use" dangerous combo.  Seems like they shoud know.


Bottom line, it's ya'lls guns.

[skarke]

Well, here we go again.  There ARE case differences, including case length.

http://www.ar15barrels.com/data/223vs556.pdf

I'm just gonna shudup.     

[alsaqr]

I have fired a few hundred thousand rounds of 5.56 mm ammo in over a dozen different .223 rifles since my Sako was re-chambered to that caliber in 1968.  The only factory .223 rifle that I would not fire a 5.56 mm military round in is the H@R/NEF single shot:  That company re-ground their reamers and their chambers vary from huge to very tight. 

There are several myths about the differences in the cartridges:

Myth 1.   US military brass is thicker than civilian .223 brass. 
 
Not so.  I weigh and segregate my brass for all my accuracy re-loads.  Go to AR-15 barrels-tech-brass weights.

Myth 2.  5.56mm ammo generates 60,000 psi:  Higher pressure than civilian .223 ammo. 

Go to page 10-3 of US Army TM 43-0001-27 and find out that the M193 5.56mm round generates 52,000 psi.

http://www.scribd.com/doc/13027441/ammo-data-sheets-small-caliber-firearms 

Would SAAMI lie to you.  You bet that SAAMI would lie.  For over 20 years SAAMI said nothing about the alleged difference between civilian and military 5.56mm/.223 ammo.  Then after all that cheap military ammo started coming into the US SAAMI became alarmed by their competition so they lied.

SAAMI asked the BATFE to re-write the regulations for ammo storage and manufacturing plants.  When the draft BATFE regs came out SAAMI lied like a wet stinky dog and whined about the new regulations.  They got the NRA-ILA to lie for them and the NRA demagogued on the issue. 

For many years Ruger rifles has seen fit to say that you can fire either 5.56mm or .223 ammo in their rifles.  Yes, there are some tight match chambers in .223 that should not have 5.56mm ammo fired in them. 

 

[trotterlg]

Also, most (not all) rifles now in .223 were also chambered in 17 Remington which is the same size case head but had a SAAMI pressure of 52,000 cup, I know there is no direct conversion to PSI however you can bet it is over 60,000psi.  I would like to see any verified report of any nato round damaging a .223 rifle.  I have never seen one that wasn't something like "My cousins brother had a friend that blew up his rifle by.........."  Like I said, I think it is the boogy man.  Larry

[pastorp]

Sharke, I respect your attitude and believe you are sincere. I also believe you are sincerely wrong. It's this kind of misinformation that taints the truth. I have shot thousands of rounds of military ball ammo in comercial rifles without problems.

I respectfully submit that your decission to drop the subject is the best idea you've had on this topic.

Regards

[skarke]

I guess you guys are right. I've been involved with BR shooting for a while now, and chamber dimensions are maybe a little too critical to my previous posts. It seems that most all factory rifles have enough forgiveness to accomodate a variety of brass, including military brass, with the possible exception of freebore, or leade if you like. I have a bushmaster 223 that eats anything. But, I wouldn't think of running the same through my SAAMI minimum spec varmint rifle, in some part as a concern posed exactly from discussions like this, but mostly because I load completely differently for the two guns.

So, I'll admit when I'm probably mistaken, but I'll still keep my brassmanbrass for my bushmaster, and reserve the Lapua for the accuracy gun.

Good shooting, and I always appreciate the opportunity to learn something.

[Merle]

Don't know where you get your case length info, but from what I find they are the same, personal opinion is that the SAAMI/NATO ratings are like the boogy man, not sure it is true at all.  There are lots of things written on this, but I think they are same-same.  Larry

http://stevespages.com/page8d.htm

FWIW, my only 223 sporter (a TC carbine) will not chamber most 5.56 loads. The action will not close, and when I inspect the case I can see the brass is "polished" at the case mouth. There are no other marks on the case, so I am inclined to say the chamber is a wee bit shorter. Never got enough of them to go off to say for sure about the pressure, but the gun opened OK and the cases extracted easily.

 

[skarke]

Man I wish that I'd never opened this can of worms.  I've done a mountain of reading since this original post (MOUNTAIN), and the bottom line is that the 5.56 and 223 are, for all practical purposes, identical.

That said, chambers do vary, and military chambers are usually a little sloppier than sporter arms, BUT NOT ALWAYS!!!  The guys on this post set me straight.  The brass is the same, except for very minor lot to lot variations.

[saltydog]

The first time you reload it the point is mute - sevral mfg's use a Wylde chamber to compensate for any difference. Think of the typical use of mil spec 5.56 ammo - full auto fire in M16's not for use in a bench rest / varmit rifle. The thickness of the brass case wall varies by mfg. and lot. That said you should pay attention to the brass when reloading mil spec 5.56 brass such as Lake City to max loads as the case capacity can be less and you could create a high pressure cartridge.