.223 vs 5.56

One thing to point out. Ruger actions are made very strong. Technically they are the strongest of the main Manufactuers. Colt, Sig, Remington, etc, etc. so I don't hink using slightly higher pressure rounds would hurt the gun. Now if you had some no name $150.00 Rifle I might tell you differently.
 
here is the skinny from my favorite LTC:
<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>There are no "cartridge" headspace specs. There are, however, weapons
headspace specs. There is, for example, no 5.56mm NATO headspace spec.
All depends on the weapon in question. SAAMI has adopted a recommendation
for bolt action rifles. Using this in other firearms is a mistake.

Semiautomatic and automatic weapons have larger headspace specifications to
insure proper functioning. There are separate headspace specification for
the M14 rifle and the various 7.62mm NATO machineguns for example, just
like there's a different spec for the M16A2 and M249 SAW, both of which are
5.56mm.

I get really tired of the old women in the world worrying about "excessive
headspace." Unless one uses a grinder there's no way you can get
"dangerous headspace." You'll wear out the barrel first.

There are no safety or any other issues firing .308 ammunition in the M14 and other 7.62mm NATO weapons provided the weapons meet weapon headspace
requirements. Same for .223 in the M16A2 or SAW.

Nit picking and quibbling aside 7.62mm NATO and .308 Winchester are
functionally identical meaning you can fire either cartridge with impunity
as needed. Same for 5.56mm NATO and .223 Remington.

Military cartridges normally have thicker cases making them smaller on the
inside than commercial cases. Outside they're the same within tolerances.

Anyone who tells you that 7.62mm and .308 have different "headspaces"
hasn't a clue what headspace's function is. Same same for 5.56mm and .223.
Weapons have headspaces, not cartridges.

For reliable operation the AR15 should use the M16A2 headspace. Notice
there's no mention of caliber here.

- -- Chuck[/quote]
 
dZ: A couple of minor quibbles on the headspace thing: Too tight a chamber, the bolt won't close or lock into battery. Too much headspace in the chamber, and the case might seat just enough forward that it's possible for the primer to be blown out, making life exciting for the shooter.

The latter case is of significance only on "put together" guns--typically older military bolt actions--where one has no idea of the history. For currently-shot rifles, it's almost unheard of...

No biggie, Art
 
The whole thing is not very complicated. If you have a .223 barrel, it probably has a tighter chamber. It may have trouble shooting 5.56mm ammo reliably. It may not. My Bushmaster has a big problem with 5.56mm ammo. My Mini-14 does not. If you want to increase the chance that your rifle will function reliably with anything you put in it-buy a 5.56mm barrel. It may not have the "match accuracy" of a .223 barrel, but it will be more likely to happily digest your ammo without faillure in adverse conditions. A bolt action rifle is a different animal. The fact that is safe to fire 5.56mm in a Ruger M77 really has nothing to do with the question.

If there was no difference, why would SAAMI say there is a difference?
 
What it boils down to is that the 5.56x45mm and 223 are the same cartridge. But when it says 5.56 the cartridge [or gun] is not held to SAAMI tolerances...the 5.56 is held to what NATO specs? You can run into the smae problem with 9x19mm ammo or 45 acp.

If you think that is the problem with your AR take it in and have them slip go/no go gages in or take a caliper to your rounds before you shoot them and check OAL.

If long (measured) rounds give you problems then you have ID the problem. You might also look at bullet shape.
 
PEOPLE, PEOPLE

***PLEASE***

It's a PRESSURE difference, NOT a cartridge case dimension difference!!!!!!

Let me demonstrate it another way. You have a revolver, chambered for 38Special, which it says. You have a pocket full of cartridges loaded to 38, and some with the headstamp 38+P. Now, both the 38 and 38+P are dimensionally the SAME. Always were, always will be. Is it safe to shoot those +P through your gun? Maybe, maybe not. To be safe, you need a gun that is rated for 38+P, right?
SAME LOGIC APPLIES TO .223 and 5.56mm NATO, with the added complication of gas pressure and bolt/carrier velocity!!!!!!!!!!!!!!!!!!!!


IT'S A PRESSURE THING, MAN!!!!!!!

Now, go back and read Mountain and my first posts, as well as those by dz.

Tom

------------------
A "Miss" is the ultimate overpenetration!
You can never be too rich, too skinny, or too well armed!
Wake up and realize that you have the moral imperative of action..!!!

[This message has been edited by Banzai (edited August 02, 2000).]
 
Banzai: Gotta quibble with ya, a bit. With GI ammo, if I've never seen pressure signs in my bolt-action .223, or had a problem with any of 3 or 4 Mini-14s, why should I expect any in the future? That's a bunch of ammo, since whenever Ruger first produced the Mini and I bought my first one. Over 25 years? My mind remembereth not. Any pressure difference seems to be very, very trivial.

I also have great difficulty believing the mechanism of the M-16 is stronger than a bolt action.

Last, if there were indeed a real-world problem, I think the gunzines would have yawped about it at great length, and all manner of warnings would be all over the place. Commercial manufacturers would much rather see me buy their product, rather than glom on to military surplus...

Regards, Art
 
Ok so the S&B ammo I have is marked:

.223 (5,56x45) (yeah they used a comma)

And my Bushy lower is marked .223-5.56

So can I use either? I have used both .223 and 5.56 and had no problems feeding, but which is better to use? or does it even matter?
 
Art, I never said there was a problem. As you pointed out, you MAY NEVER have a problem using 5.56 in a .223 marked gun, especially a bolt gun. I also stated this in my first post! The problem is in when you DO have a problem, as could be seen when mixing ammo, usually reloads, between an AR and a Mini. The AR gas system requires much more gas than the Mini, and ammo that cycles an AR can SOMETIMES cause problems in a Mini, to wit: the latest import SS109(5.56 NATO headstamp) from Spain, which is locking up many ARs with too much pressure. Imagine what it would do to a Mini??? :)
The question posed was what was the difference, and I answered with what the difference is, from SAAMI's point of view.
To clear this up, perhaps someone could actually find some pressure data for 5.56mm NATO, since it seems to be sorta hard to find, whereas .223 seems to be in several load manuals?? Just a thought!

Tom


------------------
A "Miss" is the ultimate overpenetration!
You can never be too rich, too skinny, or too well armed!
Wake up and realize that you have the moral imperative of action..!!!
 
Banzai: "...the latest import SS109(5.56 NATO headstamp) from Spain, which is locking up many ARs with too much pressure."

Is this stuff for issue to NATO troops in Europe? If so, Oh Joy, Oh Joy! I'm just glad my son got the #$%# out of the service!

I won't comment further...

Art
 
i think the problems may stem from reloading ammo

5.56 brass is thicker so the powder capacity of the cartridge is different

If the 5.56 chamber is larger and you shoot .223 brass in the gun, then the thiner .223 brass is stretched and needs resized when reloading.

Last time i checked, the Military doen't consider policing brass & reloading ammo a priority. Even AR magazines are disposable.

dZ
 
Just got an email back from Bushmaster. I asked what to use as my Bushy is markerd .223-5.56 and they said it is chambered for 5.56 but .223 works fine too. But said to stick with the 5.56 for better results.
 
You must log in or register to reply here.
Back
Top