Ok, I'm a dummy. Explain .223 vs 5.56 to me please

[Guest MilitiaMan]

I have a Core 15 Scout M4. I have bought a ton of 5.56 for it.

 

Now, I see several cases of .223 (5.56x45) for sale andnot sure to buy.

 

My concern is that I have heard people talking about "don't shoot .223 through a rifle chambered 5.56 or it will damage it". Or it might be vice versa.

 

 

I would appreciate it if someone could school me on this source of confussion lol

 

Thanks.

[babelt]

If your rifle is rated for 5.56 it will shoot 223. If it is just rated for 223 don't shoot 5.56. I am not the up most expert but 5.56 is the hotter round. The core rifles should be rated for 5.56 but look on the barrel to double check. 

[atlas3025]

You can shoot 223 through a 5.56 safely.  It just may not be quite as accurate because the bullet is seated a little more deeply, so the bullet has to travel a hair further before it engages the rifling of the barrel. 

 

The risk is going in the other direction.  A 5.56 round in a 223 will possibly touch the rifling when chambered, which will cause higher pressure.  But even then it isn't likley to be a problem. 

[gjohnsoniv]

There is a difference between the SAAMI specs and mil specs on the leade of the round. You can fire .223 through through a 5.56 barrel but not recommended for vice versa. The other option is a Wylde chamber.

[Dolomite_supafly]

The difference between 223 and 5.56 is pressures of the loaded ammunition. 5.56 is actually loaded to a higher pressure, 10K-15K, than commercial 223. And because it is loaded to a higher pressure something must be done to reduce pressures and that is why a 5.56 chamber generally has a longer throat. The long throat allows pressures to begin to drop before they encounter the resistence of the rifling.

 

Firing 5.56 is a gun chambered in 223 is not going to result in a catastrophic failure of your gun. It will cause a bit more wear and tear on your firearm. If your 223 firearm blows up from shooting 5.56 then your gun has some serious issues. Is it recommended to shoot 5.56 through a 223 chambered gun, no. But doing so from time to time will not cause the world to stop spinning or gravity to reverse like some people seem to imply. Pressure signs yes but no dramatic failure.
 

There are a lot of guns that are marked with 5.56 chambers that are actually 223 chambers. And likewise I have checked the throats on several guns chambered in 223 and they were longer than 5.56's throat. There is an article where 1 in 4 "5.56" guns actually have 223 chambers. If a 223 chamber resulted in a kaboom when firing 5.56 there would be a lot of guns blowing up.

 

I have a AR chambered in match 223 that I shoot 5.56 out of regularly and have yet to see a single problem.

 

Dolomite

[Guest MilitiaMan]

Thank you guys.

[battleop]

I have a Core 15 Scout M4. I have bought a ton of 5.56 for it.

 

Now, I see several cases of .223 (5.56x45) for sale andnot sure to buy.

 

My concern is that I have heard people talking about "don't shoot .223 through a rifle chambered 5.56 or it will damage it". Or it might be vice versa.

 

 

I would appreciate it if someone could school me on this source of confussion lol

 

Thanks.

 

.223 is to 5.56 as .38 is to .357 or 44 special is to 44 mag.  

[Fourtyfive]

The difference between 223 and 5.56 is pressures of the loaded ammunition. 5.56 is actually loaded to a higher pressure, 10K-15K, than commercial 223. And because it is loaded to a higher pressure something must be done to reduce pressures and that is why a 5.56 chamber generally has a longer throat. The long throat allows pressures to begin to drop before they encounter the resistence of the rifling.

Firing 5.56 is a gun chambered in 223 is not going to result in a catastrophic failure of your gun. It will cause a bit more wear and tear on your firearm. If your 223 firearm blows up from shooting 5.56 then your gun has some serious issues. Is it recommended to shoot 5.56 through a 223 chambered gun, no. But doing so from time to time will not cause the world to stop spinning or gravity to reverse like some people seem to imply. Pressure signs yes but no dramatic failure.

There are a lot of guns that are marked with 5.56 chambers that are actually 223 chambers. And likewise I have checked the throats on several guns chambered in 223 and they were longer than 5.56's throat. There is an article where 1 in 4 "5.56" guns actually have 223 chambers. If a 223 chamber resulted in a kaboom when firing 5.56 there would be a lot of guns blowing up.

I have a AR chambered in match 223 that I shoot 5.56 out of regularly and have yet to see a single problem.

Dolomite

After reading and reading and searching I thought I had a handle on this ; chamber closed. Edited March 8, 2013 by Threeeighty

[Rowdy]

.223 is to 5.56 as .38 is to .357 or 44 special is to 44 mag.  

Or, as 308 is to 7.62. :)

[dlm37015]

223 556 is the same the chambers are a little more free bore in the 556 but the ammo is the same

sammi spec is the same same powder charge same brass same bullet same thing check it out with sammi

go to an ammo plant they only load 1 load you get higher pressures with some bigger bullet loads m262 comes to mind

the reason for the free bore is because in the field ammo might be hot higher temps henceforth higher pressure

i have the sammi and us lake city specs if someone would like to see them

[Reservoir Dog]

Or, as 308 is to 7.62. :)

Actually, it is the opposite when talking about .308/7.62.  The .308 WIN cartridge has a higher pressure than the 7.62 NATO.  Therefore, a .308 chambered rifle can shoot both, but .308 is not recommended for use in a 7.62 NATO chambered rifle.

[Oh Shoot]

The difference between 223 and 5.56 is pressures of the loaded ammunition. 5.56 is actually loaded to a higher pressure, 10K-15K, than commercial 223. And because it is loaded to a higher pressure something must be done to reduce pressures and that is why a 5.56 chamber generally has a longer throat. The long throat allows pressures to begin to drop before they encounter the resistence of the rifling.

 

....

 

Unlike SAAMI, which I understand as 5.56 at max 62,000 psi vs .223 at max 55,000 psi, CIP specs for 5.56 and .223 are the same: max 62, 000 psi.

 

It is my understanding that given same NATO spec load, the only reason some 5.56 is higher psi than .223 is because for a time military brass was a bit thicker than commercial .223, hence same powder charge in slightly smaller capacity casing equaled more pressure.

 

And that the only real difference in the longer leade ("throat")  in the 5.56 chamber was to better accommodate the heavier and longer bullets which were were only speced for possible military usage at the time the original chamber depth was also speced due to initial testing by Armalite and the Army?

 

- OS

Edited March 8, 2013 by Oh Shoot

[Smith]

.223 is to 5.56 as .38 is to .357 or 44 special is to 44 mag.  

No. Different issues there.