Excuse a stupid question from a newbie 5.56/.223

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[ARCHIVED THREAD] - Excuse a stupid question from a newbie 5.56/.223

Posted: 8/17/2005 10:07:29 PM EDT

I've been a long time lurker (I have never owned or fired an AR-15) and am interested in the SEBR group buy. I am trying to get some things straight so that I can have accessories here before the rifle shows up.

In the spec sheet http://photos.ar15.com/images/products/m4-a3_sebr_carbine.pdf it states that the gun is 5.56mm OR.223.

I figured out that converting the numbers doesn't add up, so my stupid question is this:

Are the rounds in this gun interchangable, or is this telling me to select one or the other?

Posted: 8/17/2005 10:08:28 PM EDT

[#1]

SAMMI Specs.

Posted: 8/17/2005 10:08:57 PM EDT

[#2]

shoot either they will both work it is just stating it will shoot military spec ammo

Posted: 8/17/2005 10:10:26 PM EDT

[#3]

www.ammo-oracle.com/body.htm

All you would ever want to know is explained here

Posted: 8/17/2005 10:10:29 PM EDT

[#4]

Tons of info

Ammo Oracle .223 vs 5.56

Enjoy your new rifle!

EPOCH

ETA: damn, beat by 3 seconds!!!

KOOTER
Posted :: 8/18/2005 2:10:26 AM EDT

Posted: 8/17/2005 10:10:58 PM EDT

[#5]

The carbine is chambered to fire military 5.56 ammunition, therefore it can also fire the less powerful (a little slower) .223 ammunition.

Posted: 8/17/2005 10:12:18 PM EDT

[#6]

Short Answer: The rounds are interchangeable and almost the same.

Long Answer: Taken from the Ammo Oracle.

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.

Posted: 8/17/2005 10:20:43 PM EDT

[#7]

Quoted:
Tons of info

Ammo Oracle .223 vs 5.56

Enjoy your new rifle!

EPOCH

ETA: damn, beat by 3 seconds!!!

KOOTER
Posted :: 8/18/2005 2:10:26 AM EDT

[nelson]...HA-HA...[/nelson]

[ARCHIVED THREAD] - Excuse a stupid question from a newbie 5.56/.223

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