Is a 5.56 the same as a .224 ?

**sid** · May 19th, 2009, 07:50 PM

I had read somewhere that a 5.56mm round is also a .224 . Is there any truth to this? I had only read it in maybe 2 places and both were on sites that sell barrels. Their available barrel chamberings among others were .223 and .224, they never mentioned a 5.56 chambering. Needless to say I didn't even think about buying a bbl from them because I was looking for a 5.56 chamber and figured they weren't the same. I wanted to be safe rather than sorry. I have since gotten a bbl but am curious as to if the .224 is the same.
This a .224 round I saw for sale (very expensive):

Caliber :224 Weatherby Mag
Bullet Type :Spire Point
Bullet Weight :55 GR
Muzzle Energy :1627 ft lbs
Muzzle Velocity :3650 fps

sid

**338winmag** · May 19th, 2009, 08:18 PM

Originally Posted by sid

I had read somewhere that a 5.56mm round is also a .224 . Is there any truth to this? I had only read it in maybe 2 places and both were on sites that sell barrels. Their available barrel chamberings among others were .223 and .224, they never mentioned a 5.56 chambering. Needless to say I didn't even think about buying a bbl from them because I was looking for a 5.56 chamber and figured they weren't the same. I wanted to be safe rather than sorry. I have since gotten a bbl but am curious as to if the .224 is the same.
This a .224 round I saw for sale (very expensive):

Caliber :224 Weatherby Mag
Bullet Type :Spire Point
Bullet Weight :55 GR
Muzzle Energy :1627 ft lbs
Muzzle Velocity :3650 fps

sid

no 5.56 is 223 but the 5.56 is a higher preshser round than the 223.that is why you can shoot 223 out of a gun marked 5.56 but not the other way around.

**novice** · May 19th, 2009, 08:20 PM

5.56x45mm NATO is the same as .223 Remington. It was developed for use in the M-16. Not sure if they're truly identical in the milspec vs. commercial version; previous post says they're not truly interchangable.

http://en.wikipedia.org/wiki/5.56x45mm_NATO

**knight0334** · May 19th, 2009, 08:25 PM

You have to separate the name of the round from the diameter of the bullet.

5.56mm bullets are .224 calibre. A .224" bullet can be used in a number of other cartridges. 223Rem, 222Rem, 222Rem Mag, 220Swift, 22-250, 5.56Nato, 224Wby Mag, etc, etc, etc..

**RaisedByWolves** · May 19th, 2009, 08:25 PM

Lots of info on .223 Vs 5.56 on here, search it out.

**sid** · May 19th, 2009, 08:30 PM

I know the 5.56 is the same as the .223 but thought since the 5.56 is millimeters and the .223 is inches maybe the 5.56 could be slightly larger thus the .224. I know you should never shoot a 5.56 from a .223 barrel but if the .224 chamber allows for a greater headspace making it possible to shoot the 5.56 in a .224 barrel. Not exactly but kind of like 9mm, .38 special and .357 Mag.

sid

**sid** · May 19th, 2009, 08:32 PM

Originally Posted by RaisedByWolves

Lots of info on .223 Vs 5.56 on here, search it out.

I'm not comparing the .223 to 5.56

sid

**sid** · May 19th, 2009, 08:34 PM

Originally Posted by knight0334

You have to separate the name of the round from the diameter of the bullet.

5.56mm bullets are .224 calibre. A .224" bullet can be used in a number of other cartridges. 223Rem, 222Rem, 222Rem Mag, 220Swift, 22-250, 5.56Nato, 224Wby Mag, etc, etc, etc..

So you can shoot a 5.56 nato round through a bbl chambered in .224 but not a bbl chambered in .223 correct?

sid

**knight0334** · May 19th, 2009, 08:49 PM

Originally Posted by sid

So you can shoot a 5.56 nato round through a bbl chambered in .224 but not a bbl chambered in .223 correct?

sid

NO... You're missing what I'm saying. The 5.56nato and the 224Wby Mag have the same bore down the barrel. The chambers and casing are different.

The bullets are the same, the casings and the corresponding chambers are different.

See the difference..

**sid** · May 19th, 2009, 08:57 PM

OK cool. Thanks for the clearing this up for me. Like I said I knew about the .223 issue and have read it many times. I just thought (from what I had read somewhere else) that the .224 would be ok with 5.56.

Thanks,
sid

edited to add:
I didn't think about the case differences.