5.56 or 223 , whats the difference

[bored2bhere]

ive heard that you shouldnt shoot 223 in 5.56 chambered rifles and vice versa is there a difference ? i thought 5.56 was just the metric name of the 223 can anybody tell me???

[troylaplante]

I have often heard the same thing, and then I have also read articles online that contradict the warnings. I literally have ammo boxes that say BOTH on them. Go figure.

[Tex in Maine]

from what I have read it is ok to shoot 223 in 5.56, but you should'nt fire 5.56 in a 223 chamber because it is slightly longer.

try this link..

Winchester Law Enforcement

[.22guy]

I think some ammo labeled 5.56 is also military, so it will be loaded hotter, which might not be safe in some civilian guns.

[Big Dog]

I had major problems shooting surplus 5.56 in a Contender - it locked the action! Any commercial .223 worked fine.

Military chambers tend to be looser in tolerance, so as to prevent jams in the heat of battle.
My Bushmaster handles both types equally well.

[DWARREN123]

The standards are slightly different. If you have a .223 Rem match chamber then do not use 5.56mm in it. If you have a 5.56mm chamber or intermediate (Wyilde sp) chamber then you should be okay on both.
What does the instructions, that came with the firearm, say?

[lefty o]

the 5.56 is loaded to slightly higher pressures, and also has the leade in the chamber cut slightly longer. these are the only differences. you can therefore safely fire any 223 ammo in a 5.56 chambered rifle. firing 5.56 in a 223 chambered rifle is not a sure bet, and i wouldnt recommend it, though you may or may not get away with it.

[JoeLee]

FEEDBACK.Better then I can say it.
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Q. What is the difference between 5.56×45mm and .223 Remington ammo?
In the 1950's, the US military adopted the metric system of measurement and uses metric measurements to describe ammo. However, the US commercial ammo market typically used the English "caliber" measurements when describing ammo. "Caliber" is a shorthand way of saying "hundredths (or thousandths) of an inch." For example, a fifty caliber projectile is approximately fifty one-hundredths (.50) of an inch and a 357 caliber projectile is approximately three-hundred and fifty-seven thousandths (.357) of an inch. Dimensionally, 5.56 and .223 ammo are identical, though military 5.56 ammo is typically loaded to higher pressures and velocities than commercial ammo and may, in guns with extremely tight "match" .223 chambers, be unsafe to fire.
The chambers for .223 and 5.56 weapons are not the same either. Though the AR15 design provides an extremely strong action, high pressure signs on the brass and primers, extraction failures and cycling problems may be seen when firing hot 5.56 ammo in .223-chambered rifles. Military M16s and AR15s from Colt, Bushmaster, FN, DPMS, and some others, have the M16-spec chamber and should have no trouble firing hot 5.56 ammunition.
Military M16s have slightly more headspace and have a longer throat area, compared to the SAAMI .223 chamber spec, which was originally designed for bolt-action rifles. Commercial SAAMI-specification .223 chambers have a much shorter throat or leade and less freebore than the military chamber. Shooting 5.56 Mil-Spec ammo in a SAAMI-specification chamber can increase pressure dramatically, up to an ""additional 15,000 psi or more"".
The military chamber is often referred to as a "5.56 NATO" chamber, as that is what is usually stamped on military barrels. Some commercial AR manufacturers use the tighter ".223" (i.e., SAAMI-spec and often labeled ".223" or ".223 Remington") chamber, which provides for increased accuracy but, in self-loading rifles, less cycling reliability, especially with hot-loaded military ammo. A few AR manufacturers use an in-between chamber spec, such as the Wylde chamber. Many mis-mark their barrels too, which further complicates things. You can generally tell what sort of chamber you are dealing with by the markings, if any, on the barrel, but always check with the manufacturer to be sure.
Typical Colt Mil-Spec-type markings: C

[bored2bhere]

thanks for this guys!!! im getting me a panther carbine flattop in 5.56 and was just wondering

[rocketmonty]

Originally Posted by Tex in Maine

from what I have read it is ok to shoot 223 in 5.56, but you should'nt fire 5.56 in a 223 chamber because it is slightly longer.

try this link..

Winchester Law Enforcement

not even that, also powder loads are completely different. same way like a .308,versus the 7.62*51 are not the same load measurment's
that mean's short rifling,erosion in barrel's not suitable for heavier load's
example chrome lined barrel ,versus non chrome lined. also the factor in the rifling affects too. too much rifling