.223 vs 5.56

[walkingnam]

I used to the difference between these rifle calibers, but now I don't. My son who believes himself to be an expert on this topic I'm not sure of anything anymore. So I'm just going to plunge forward and hope that I be doing the same to the forum.

I have three AR15 rifles and my problem starts here. Olympic Arms rifle is stamped as being able to use .223 and 5.56, the one from Palmetto State Armory does not appear to have a caliber listed. While the last one from PWA is stamped 5.56. So my first set is questions is.

1: I never heard of dual calibers outside of .38spcl and .357 mag or .44special/.44 mag being able to be fired from the same firearm. So can .223 and 5.56 be fired from the same rifle without any problems.

2; Can a rifle listing 5.56 fire a .223 round without problems

3: The palmetto state armory rifle was purchased within the past few month. So why is their no caliber stamped on the receiver.

I believe that the answer to the first two questions is yes and I think that I will have to contact palmetto armory concerning my questions there.

So now to the confusion caused by my son. He is of the impression the two calibers are vastly different. He is telling me that 5.56 chambering rifles can fire .223 without a problem. But .223 chambered rifles cannot fire 5.56 with some damage being done the rifle.

I on the other hand have extensive experience with the M-16 many years ago chambered in the 5.56 and nothing with the .223. However no current experience with the .223. I was always told that both calibers were basically the same and could be fired interchangeablely without any problems. He has my head spinning so bad I'm almost dizzy. Any informed comments on this would be appreciated.

 

[ErrosionOfAccord]

Your AR's are fine. Might proceed with caution shooting 5.56 from a .223 bolt action. JMHO

223 -vs- 5.56: FACTS and MYTHS – Ultimate Reloader

ultimatereloader.com

Where much of the confusion comes when trying to understand the differences between 223 Remington and 5.56 NATO ammunition is when reading the published maximum allowed pressure for each cartridge. You may see data published that looks like this:

223 Maximum pressure (SAAMI) 380 MPa (55,000 psi) 5.56 Maximum pressure (EPVAT) 430.00 MPa (62,366 psi)

…and this data would make it appear that 5.56 NATO ammunition is certified “to a higher pressure” than 223 Remington ammunition. That is actually not the case! It’s only when we observe the US Military’s updated pressure testing and rating data when we see a parallel:

5.56 Maximum pressure (SCATP 5.56) 380.00 MPa (55,114 psi)

 

[Joe King]

He is telling me that 5.56 chambering rifles can fire .223 without a problem. But .223 chambered rifles cannot fire 5.56 with some damage being done the rifle.

I'm no expert on it, but I have looked into it in the past and have come away with the same conclusion.

 

[chrisflhtc]

My Ruger Mini 14 will fire both and I reload to some high pressures approaching max.

 

[Voodoo]

Your AR's are fine. Might proceed with caution shooting 5.56 from a .223 bolt action. JMHO

223 -vs- 5.56: FACTS and MYTHS – Ultimate Reloader

ultimatereloader.com

Where much of the confusion comes when trying to understand the differences between 223 Remington and 5.56 NATO ammunition is when reading the published maximum allowed pressure for each cartridge. You may see data published that looks like this:


…and this data would make it appear that 5.56 NATO ammunition is certified “to a higher pressure” than 223 Remington ammunition. That is actually not the case! It’s only when we observe the US Military’s updated pressure testing and rating data when we see a parallel:

Just had this conversation with my brother-in-law (ex-military). I'm a rookie mind you. He said if you go the AR route just get the 5.56 as you can fire both. If you get one rated .223 then you might have problems with some ammo.

 

[smooth]

Your lower receiver may or may not be stamped it doesnt really matter because the upper receiver is where the rifle chamber is and there are many different cartridge offerings in the AR platform. Look on your barrel towards the chamber for cartridge spec.
Also if stamped .556 there are no worries shooting .223 if shooting .556 in a chamber spec. in 223 you could supposedly see higher chamber pressure. But I believe this is due to the NATO brass on the .556 being thicker not any difference in chamber dimensions. Im sure hundreds of millions of .556 rounds have been fired through .223 designated AR15's. Having said that, due to higher chamber pressures with the .556 it is not recommended in a rifle specifically chambered in .223.

 

[Joe King]

I found this article that goes into the fine details of the differences betwixt the two.

5.56 vs 223 Ammo - What's the Difference? 19 Things You Need To Know

In this article, we compare 5.56 vs 223 ammo. This will help you know the difference between 5.56 and 223, two calibers that are very similar.

bulkmunitions.com

One difference noted, is the following.

The 5.56 also has a longer throat with a difference of .125 inches in length when compared with that of the 223 Remington bullet. The longer throat allows more holding capacity for gun powder in the 5.56, thus implying that it has a higher performance as compared to the 223 Remington.

 

[Ttazzman]

you get similar issues with 308/7.62x51

i just buy .223 and .308 speced ammo and dont worry about it

 

[walkingnam]

Joe: I understand about throat differences. But to my way of thinking if you keep cutting back on throat length then there would be no difference between the two cartridges (length wise) and possible pressure wise also. Then the big thing would be the type of powder used to which I cannot speak to.

However the article state with certainity that the 556 cannot be shot from a 223. The 223 can be shot from a 556. The effective range of the 556 is longer with the accuracy edge going to the 223 over a shorter distance. The bullet weight is higher in the 556

The article seems to back up what my son said. So I can either see contacting the Palmeto armory to see what they mean by stamping multi (caliber) on their rifle. The last thing that I or anyone would be is to chamber an inappropriate cartridge.

So it looks like the kid was right which I kind of am reluctant to tell him. I feel like I need to inspect my stash to make sure I'm safe. Old knowledge is hard to get away from. I may have to sell the Palmetto rifle and get a new 553. So tomorrow I'm off to the local gun store to possibly swap out or exchange the Palmetto made rifle (which is a fine rifle).

 

[walkingnam]

Taz In have never given a thought to the possible differences between the .308 and 7.62 x 51 I always thought that they were the same. but the .308 could be the civilian version of the 7.62 x 51. I don't want to be a worry wart or nervous nellie.

 

[Ttazzman]

Taz In have never given a thought to the possible differences between the .308 and 7.62 x 51 I always thought that they were the same. but the .308 could be the civilian version of the 7.62 x 51. I don't want to be a worry wart or nervous nellie.

I try to just stick with the .223/308 ammo when buying...and prefer a 5.56 barrel chamber when buying... but I don't fret it either way as others have said millions of rounds have been missapplied over the years especially in ar's....most lowers are marked multi caliber all that matters is barrel stamp