.223 vs .5.56 and ...

[ISCS Yoda]

...skip the and, we can do a different thread there and I will.

As I recall, if your rifle is marked 5.56 NATO you're good to go with either .223 or 5.56 but if your rifle is marked .223 you should stick to .223. I hope it's not the reverse but my memory ain't that great.

You're all thinking M&P ARs or other AR platforms. Feel free to discuss those - but my question is, what about a typical bolt action rifle - if your bolt gun is marked .223 does it matter nearly as much as in an AR type of rifle?

Thanks.

***GRJ***

 

[JJEH]

Whatever the barrel says, that's what I load.

You need to ask the manufacturer of your firearm to be 100% sure b/c 5.56 still has a higher pressure and can cause damage on your rifle.

 

[Alpo]

I agree with the "ask the manufacturer".

I have a Mini 14 and a #1. Both, according to the markings on the gun, chambered in .223 Remington. Ruger says that their Mini 14s (except for one target-model Ranch Rifle) actually have 5.56 chambers, and are safe with both.

But the nice lady I spoke to at Ruger said, "No, don't be shootin' no 5.56 in that #1. That's a .223 rifle". Well, actually, she spoke Yankee, but I translated it.

But as I understand it, as a general rule, if your gun says 5.56 you can shoot either, but if it says .223, you need to stay away from the 5.56.

Exactly opposite of the 7.62/308 controversy.

 

[Bkreutz]

...skip the and, we can do a different thread there and I will.

As I recall, if your rifle is marked 5.56 NATO you're good to go with either .223 or 5.56 but if your rifle is marked .223 you should stick to .223. I hope it's not the reverse but my memory ain't that great.

You're all thinking M&P ARs or other AR platforms. Feel free to discuss those - but my question is, what about a typical bolt action rifle - if your bolt gun is marked .223 does it matter nearly as much as in an AR type of rifle?

Thanks.

***GRJ***

You've got it correct, but of course there will be people who disagree.

 

[BAM-BAM]

CZ USA has stated that their Model 527s ( w/ their mini-mauser action) marked .223 can handle either......

 

[DR505]

Make sure you pay attention to the markings on the BARREL. I have a Colt AR-15 that says .223 Remington on the mag well, but the barrel states 5.56mm NATO. It therefor has a 5.56mm chamber and can handle either.

 

[ISCS Yoda]

My Bushmaster says .223/5.56 so I'm good there. It's my Remington Model 700 ADL in .223 that inspired my question. I forgot I had it until I was discussing something else on here.

***GRJ***

 

[CAJUNLAWYER]

I agree with the "ask the manufacturer".

I have a Mini 14 and a #1. Both, according to the markings on the gun, chambered in .223 Remington. Ruger says that their Mini 14s (except for one target-model Ranch Rifle) actually have 5.56 chambers, and are safe with both.

But the nice lady I spoke to at Ruger said, "No, don't be shootin' no 5.56 in that #1. That's a .223 rifle". Well, actually, she spoke Yankee, but I translated it.

But as I understand it, as a general rule, if your gun says 5.56 you can shoot either, but if it says .223, you need to stay away from the 5.56.

Exactly opposite of the 7.62/308 controversy.

Well, if given the choice of believing the Ruger literature or some lady on the phone who could be the cleaning lady for all you know-I'm going with the manual. If my mini blows up shooting 5.56 I'll be getting a new rifle anyway

 

[JJEH]

My Bushmaster says .223/5.56 so I'm good there. It's my Remington Model 700 ADL in .223 that inspired my question. I forgot I had it until I was discussing something else on here.

***GRJ***

That's what Remington says in their FAQ's:

Question
What is the difference between the .223 Remington and the 5.56 calibers?

Answer

Per SAAMI specifications: The 5.56 and 223 Remington cartridges are similar, but the chambers of the guns and test barrels they are evaluated in are different. One of the key differences is the length of the throat or leade on the 5.56 chamber compared to the 223 Remington.

It’s almost twice as long in the 5.56 chamber versus the 223 Remington chamber.

Typically, the 5.56 round is loaded to a higher velocity and pressure level than the 223 Remington.

Firing the 5.56 round in a 223 Remington chamber with the shorter leade can dramatically increase chamber pressures.
Therefore, we recommend against firing the 5.56 round in a 223 chamber, unless the gun is marked with both cartridge designations such as our Model 7615 Patrol Rifle.

What is the difference between the .223 Remington and the 5.56 calibers? - Remington Arms Company, LLC

 

[Arik]

Make sure you pay attention to the markings on the BARREL. I have a Colt AR-15 that says .223 Remington on the mag well, but the barrel states 5.56mm NATO. It therefor has a 5.56mm chamber and can handle either.

I have the same. I have not heard of a 223 specific AR in a very very long time

I'm surprised that a bolt action cannot handle 5.56

 

[johngalt]

Technically, you shouldn't shoot 5.56 in a .223 chamber for the reasons already stated. As a practical matter, I haven't noticed any difference in my .223 Winchester M70 with 55gr and 62 gr bullets.

Long heavy bullets are a different matter, I wouldn't shoot those in a .223. The heaviest I've done is 62 gr. Besides the safety issue, I don't think my M70 has a fast enough twist rate to stabilize the heavy bullets.

 

[RobzGuns]

Make sure you pay attention to the markings on the BARREL. I have a Colt AR-15 that says .223 Remington on the mag well, but the barrel states 5.56mm NATO. It therefor has a 5.56mm chamber and can handle either.

Yup... Same with my Colt CSR1516. The Mag Well reads .223, but the Barrel is stamped 5.56. Go by what's on the Barrel.

 

[LVSteve]

I have the same. I have not heard of a 223 specific AR in a very very long time

I'm surprised that a bolt action cannot handle 5.56

If the chamber is too short there will be too much pressure. I doubt the gun would blow up, but i bet the accuracy would be hopeless due to bullet setback and pressure spikes. probably find that extraction would be sticky, too.

 

[alwslate]

I have a Ruger 77 MKII in .223. I have fired 5.56 ammo in it with no
problems at all. The Ruger is a strong bolt action and I don't know how
the chamber is actually cut but I doubt the gun will be harmed by
mil-spec ammo. I don't shoot the 62 gr stuff in it though because i'm
sure the rifling twist is too slow to handle it.

 

[Hans Gruber]

...skip the and, we can do a different thread there and I will.

As I recall, if your rifle is marked 5.56 NATO you're good to go with either .223 or 5.56 but if your rifle is marked .223 you should stick to .223. I hope it's not the reverse but my memory ain't that great.

You're all thinking M&P ARs or other AR platforms. Feel free to discuss those - but my question is, what about a typical bolt action rifle - if your bolt gun is marked .223 does it matter nearly as much as in an AR type of rifle?

Thanks.

***GRJ***

5.56 NATO is a military spec chamber built to a slightly different spec than commerical .223 Remington chambers. The mil-spec NATO chamber has more throat or "leade" which allows the bullet to start moving sooner before meeting resistance. A shorter leade means the bullet is more likely to build pressure before making the "squeeze" from chamber to bore.

There are "studies" that suggest 5.56 NATO ammo fired in .223 chambers makes pressures above 70,000 psi which is a bit on the hot side.

The "rule" is, if you have a 5.56 NATO chamber you can shoot that plus the .223 Rem.

WHY you may ask would anyone WANT a commerical spec .223 Rem chamber? Because they tend to be more accurate. On chambers with greater freebore (leade), bullets have more propensity to become slightly offset during the explosive transition from case mouth to bore, but a "shorter" chamber means the bullet engages the rifling sooner.

There IS a "best of both worlds" chamber called the "Wylde" that allows you to shoot 5.56 NATO and .223 commerical with excellent accuracy and lower chamber pressure!

 

[ArchAngelCD]

I have a Ruger 77 MKII in .223. I have fired 5.56 ammo in it with no
problems at all. The Ruger is a strong bolt action and I don't know how
the chamber is actually cut but I doubt the gun will be harmed by
mil-spec ammo. I don't shoot the 62 gr stuff in it though because i'm
sure the rifling twist is too slow to handle it.

The common barrel twist rate in bolt action .223 rifles is 1:12 just like my Howa 1500. My Howa will stabilize a 62gr bullet just fine and even heavier (longer) bullets.

What is the twist rate of the barrel on your Ruger that you feel it won't stabilize a 62gr .224" bullet

 

[alwslate]

The common barrel twist rate in bolt action .223 rifles is 1:12 just like my Howa 1500. My Howa will stabilize a 62gr bullet just fine and even heavier (longer) bullets.

What is the twist rate of the barrel on your Ruger that you feel it won't stabilize a 62gr .224" bullet

The twist rate is 1:12 I believe. I've never shot any bullets
heavier than 55 gr out of it and I just assumed that the 62 gr
bullets would not stablilize in it. I based my assumption on
the fact that the Nato bullet is longer than a game bullet due
to being dual core, so was thinking in reference to shooting
the green tip military ammo. I thought the military had
determined that the 62 gr ammo was not properly stabilized
out of the old 12" twist M16s by testing but I could be wrong.

 

[johngalt]

Another factor that confuse the issue is labeling on commercial ammo. Some say .223 and really is .223. I have some that is labeled .223/5.56, which I'm told means it is 5.56. I have some labeled 62 gr .223 but I've been told is really 5.56.

It is highly unlikely that my M70 chamber is any weaker than a AR chamber so I don't worry about it. I just keep the bullet weight at 62 or less to avoid stabilization and long bullet issues.

 

[brucev]

Interesting thread. Have fired all manner of surplus 5.56mm in all manner of rifles marked 5.56mm and .223 Remington. The rifles have been both AR-15 and common bolt-action domestic and import bolt-action rifles. First time I ever remember shooting a bolt-action .223 was about 1983... using hand-loads and Lake City 5.56mm. The rifle was a S&W 1500 Mountaineer (I think... definitely a S&W by Howa). There was also a S&W 1500 heavy barrel varmint rifle and a Ruger No. 1 heavy barrel, Remington 700 varmint and various AR-15's. Have fired both domestic and foreign manufactured 5.56mm in these rifles. Never had a single problem at all. YMMV. Sincerely. brucev.

 

[gregintenn]

I've never had a promblem using the two interchangeably. A web search will provide a lifetime supply of conflicting information.

To be on the safe side, you'll probably want to stick with manufacturers' recommendations for specific rifles.