[Palladin8]

OP you're better off sticking with 223 Rem than chance damaging your firearm or yourself if the gun were to let go.

I have seen first hand what firing XM193 5.56x45 will do to a .223 Rem chambered rifle. It was a S&W AR-15 and it blew up the gun. S&W would not honor their warranty because 5.56 was fired in it when it was clearly marked 223 Rem.
The upper receiver was sitting in the gun room of the person I know as a reminder that you shoot what your gun is chambered for.
He told me that it was the second box of ammo he had put through it that caused it to let go.

5.56 is loaded to a higher pressure than standard .223 Rem. The chamber is cut slightly different and has a longer lead (think Weatherby) to accommodate any NATO nations ammo.

If anyone on here would like to read up more on this and see people's damaged guns you can find them online or even on AR15.com forum.

 

[mouser868]

OP you're better off sticking with 223 Rem than chance damaging your firearm or yourself if the gun were to let go.

I have seen first hand what firing XM193 5.56x45 will do to a .223 Rem chambered rifle. It was a S&W AR-15 and it blew up the gun. S&W would not honor their warranty because 5.56 was fired in it when it was clearly marked 223 Rem.
The upper receiver was sitting in the gun room of the person I know as a reminder that you shoot what your gun is chambered for.
He told me that it was the second box of ammo he had put through it that caused it to let go.

5.56 is loaded to a higher pressure than standard .223 Rem. The chamber is cut slightly different and has a longer lead (think Weatherby) to accommodate any NATO nations ammo.

If anyone on here would like to read up more on this and see people's damaged guns you can find them online or even on AR15.com forum.

Like I've always been told, it might not be the first one, but it will be the last one.

 

[BigEd63]

OP you're better off sticking with 223 Rem than chance damaging your firearm or yourself if the gun were to let go.

I have seen first hand what firing XM193 5.56x45 will do to a .223 Rem chambered rifle. It was a S&W AR-15 and it blew up the gun. S&W would not honor their warranty because 5.56 was fired in it when it was clearly marked 223 Rem.
The upper receiver was sitting in the gun room of the person I know as a reminder that you shoot what your gun is chambered for.
He told me that it was the second box of ammo he had put through it that caused it to let go.

5.56 is loaded to a higher pressure than standard .223 Rem. The chamber is cut slightly different and has a longer lead (think Weatherby) to accommodate any NATO nations ammo.

If anyone on here would like to read up more on this and see people's damaged guns you can find them online or even on AR15.com forum.

I'd like to know what model of S&W M&P15 that was. Most have a 5.56NATO chamber.

 

[runfiverun]

it isn't the chamber.
those are identical down to pretty much every detail.
okay more like down to the cheapness of the makers reamer sharpening skills or you know how many times he uses it before replacing it.

anyway it comes down to the throat shape and the amount of powder stuffed into the case.
the bullets construction plays a large part in the 223 thing too.
it all adds up or down and it goes up much quicker than it goes down.

anyway the larger throat on the 5.56 rifles is just like adding that much more room to the case capacity of the round.
it allows some of the expanding gas to escape around the bullet, and it gives more volume to the boiler room, both things lower pressure [and velocity]

hence the jack it back up to where we were before thing causing a problem in a gun without those features.

 

[PaleHawkDown]

AFAIK, the difference is in OAL and chamber pressure, the 5.56 is slightly longer and higher, respectively. I shoot them interchangeably, as well as my hand loads, in ALL my .223 and 5.56 chambered long guns and bolt pistols. In my world, there are no dangerous factory rounds in this caliber, in any modern gun. YMMV.

I have listened to all the "experts" and arm chair Generals debate this topic ad nausiem. AFAICT, There is no cause for alarm. Even a short chamber/long neck, high pressure round combination is not likely to raise chamber pressures to a dangerous level.

Accuracy of the wilde chamber, (really just a long throated .223), has been subject to much testing and hand wringing, that jury is still out. Until I get one that will not stay under 1/2 MOA, I don't care that much
Over ambitious hand loads are a different matter entirely. (If I didn't reload it, I don't shoot it)

Just another old man's opinion.

Paul

To me interchanging rounds like this in firearms not designed for it is the equivalent of pouring whiskey in a gas tank.

You can do it. It may even work better in the short run. Every time you do it, though, you increase the chances of causing a catastrophic failure, and that says nothing of the additional wear on parts.

 

[bsshog40]

Thanks y'all for all the help and comments. Yep, gonna stay with just .223's in this gun. Lol

 

[MosinRuger]

Come on peeps, what the OP is wanting to know is whether his Saiga 223 actually has a 223 Remington chamber or whether Saiga chambers them in 5.56x45 NATO . . .

I was thinking the same thing, and believe that to be the case. dont they ( europe and russia and virtually everywhere but here) have some thing about military calibers not being allowed for civilians to own, so they may have just stamped it .223 to make it more accessible, but im pretty sure if its a well built ak action, it should be able to handle 5.56.

but since im not 100% i decided not to comment initially thinking someone else would surely know and not wanting to add to the already muddy water.

 

[Palladin8]

I did a quick search and this is the first article I pulled up. This shows the difference in the two chambers and also has explanations and picture of what will potentially happen from shooting the wrong ammo in the wrong gun.

https://www.80-lower.com/blogs/80-lower-blog/5-56-nato-vs-223-remington-223-wylde/

 

[Palladin8]

I'd like to know what model of S&W M&P15 that was. Most have a 5.56NATO chamber.

I honestly am not sure what the model was. This was back in 2009 or 10. The person who bought it was just getting into guns at that time because of then President Obama.

 

[BudW]

I'm finding a lot of conflicting information on this subject. I have a Saiga .223 and I was wondering if it was also chambered for 5.56. Does anyone here know for sure? Thanks!

My understanding is not advisable to shoot 5.56 out of a .223 but a 5.56 barrel you can shoot .223

 

[writerinmo]

http://forum.saiga-12.com/index.php?/topic/52973-raac-response-about-shooting-556-in-your-223-saiga/

 

[reverendg]

It’s a good question. I know the older mini-14’s were marketed as .223 weapons, but the manual stated that they were actually chambered for 5.56 rounds. But you had to look to find the info.

 

[chesterwin]

It’s a good question. I know the older mini-14’s were marketed as .223 weapons, but the manual stated that they were actually chambered for 5.56 rounds. But you had to look to find the info.

In doing a recent partial mag. inventory I found some mini 14 mags. I forgot I'd ordered and this thought crossed my mind. I need to find the manual and give it a look. Thanks.

 

[TXplt]

There is no AR platform I have that will not shoot 5.56/.223 interchangeably but usually the accuracy in 5.56 is significantly degraded in all but the .223 Wylde upper. I know of only one case in a semi (Ruger) where it won't shoot both .223 and 5.56 of US manufacturers. On almost all US modern manufactured guns the caliber is stamped on the barrel.

WITHOUT definitive manufacturer guidance on an unknown chamber and unknown rifle I'd not shoot 5.56 in it. Sorry if that doesn't answer your question; I haven't read any posts here which definitively know which chamber your rifle has so lacking this information I'd stick to .223.

 

[bsshog40]

There is no AR platform I have that will not shoot 5.56/.223 interchangeably but usually the accuracy in 5.56 is significantly degraded in all but the .223 Wylde upper. I know of only one case in a semi (Ruger) where it won't shoot both .223 and 5.56 of US manufacturers. On almost all US modern manufactured guns the caliber is stamped on the barrel.

WITHOUT definitive manufacturer guidance on an unknown chamber and unknown rifle I'd not shoot 5.56 in it. Sorry if that doesn't answer your question; I haven't read any posts here which definitively know which chamber your rifle has so lacking this information I'd stick to .223.

Yea, I was just curious. I don't plan on using anything other than. 223's. It was a question out of curiosity. When we were at the gun show a couple weeks back, one of the vendors was telling me there was no difference. Not sure he knew what he was talking about.

 

[TXplt]

Yea, I was just curious. I don't plan on using anything other than. 223's. It was a question out of curiosity. When we were at the gun show a couple weeks back, one of the vendors was telling me there was no difference. Not sure he knew what he was talking about.

Ya......he didn't lol.

Oddly enough I get better performance from fiocchi and Speer Gold Dot .223's than the 5.56 green tips or XM193s although the 5.56 operate at higher pressures (all of what I have can use either 5.56 or .223). Comes down to what a certain upper (barrel/chamber) likes; the Gold Dot have shot consistently well in just about everything I have and the fiocchi in most everything (and were cheap before the latest ammo run). Oddly, the only thing that doesn't seem to like the fiocchi 55's is my 1/8 11.5" PSA upper build (it does just fine with the gold dots); even it isn't bad but not of the same accuracy as my 10.5's with the fiocchi. All of them like the Gold Dot 64s especially well and do well with the Gold Dot 55's as well.

 

[Ron The Legend]

My H&R varmint heavy barrel single shot chambered in.223 will only shoot .223. 556 will stick in the chamber most times and will not eject the shell and it will have to cool off and be driven out with a cleaning rod. .556 brass resized to .223 and trimmed work just fine.

 

[reverendg]

I know for a fact that there exist National Match ar-15s that are chambered for .223, not 5.56x45, and should not be used with 5.56 ammunition. Wylde chambers are now sometimes found in NM rifles, but the competitors I knew always had match grade .223 chambers, and this was typical.

There is no AR platform I have that will not shoot 5.56/.223 interchangeably but usually the accuracy in 5.56 is significantly degraded in all but the .223 Wylde upper. I know of only one case in a semi (Ruger) where it won't shoot both .223 and 5.56 of US manufacturers. On almost all US modern manufactured guns the caliber is stamped on the barrel.

WITHOUT definitive manufacturer guidance on an unknown chamber and unknown rifle I'd not shoot 5.56 in it. Sorry if that doesn't answer your question; I haven't read any posts here which definitively know which chamber your rifle has so lacking this information I'd stick to .223.

 

[bsshog40]

So I had to jump in again. I found this ad of someone selling a saiga 223. It looks just like mine and 5.56 is not on the gun itself. Here's a link to his description he is giving and also this is a pic of the label on the box. My serial number is not far from his either so I know it's the same gun.

https://www.gunsamerica.com/9732935...23-Rem-5-56-BANNED-New-LAYAWAY-OPTION-170.htm

 

[xOFSx]

So I had to jump in again. I found this ad of someone selling a saiga 223. It looks just like mine and 5.56 is not on the gun itself. Here's a link to his description he is giving and also this is a pic of the label on the box. My serial number is not far from his either so I know it's the same gun.

https://www.gunsamerica.com/9732935...23-Rem-5-56-BANNED-New-LAYAWAY-OPTION-170.htm

View attachment 147296

I'm not an expert but I heared Izhmash actually creates AKs chambered in 5.56x45 NATO but labels them as 223. for obvious (and red highlighted) reasons.