ATOT Gun Nuts, Skool me on 556/223 please.

[Gillbot]

I've been looking at uppers to match up with my ordered lower. Everyone says to look for a 556 upper since it can shoot either 556 or 223 ammo. Fine, how the hell do I tell?
I saw this: http://www.joeboboutfitters.com/DPMS_Oracle_Upper_A3_Flat_Top_223_16_Lightweight_p/dpms-dpba-oce.htm

Listed as 223 REM or 556 NATO, is that enough to indicate it's safe for both?

 

[coxmaster]

Listed as 223 REM or 556 NATO, is that enough to indicate it's safe for both?

Generally yes. Plus receivers would usually be stamped, not sure about an upper.

 

[Vic Vega]

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[jhansman]

You would do better to head over to The High Road or The Firing Line for in-depth info on this topic.

 

[Joseph F]

Personally, I wouldn't put a .223 round in a rifle chambered for 5.56, or vice-versa.
It might not be outright dangerous, but I just don't like the idea of it.
(Not that I'm very knowledgeable on the subject, anyway)

 

[Nebor]

Guns stamped 5.56 can safely use 5.56 and .223.

Guns stamped .223 can safely use .223.

Guns stamped 5.56 & .223 can safely use 5.56 & .223.

This.

 

[Merad]

Personally, I wouldn't put a .223 round in a rifle chambered for 5.56, or vice-versa.
It might not be outright dangerous, but I just don't like the idea of it.
(Not that I'm very knowledgeable on the subject, anyway)

My understanding is that the only real difference between them is the pressure, with 5.56 > .223. So a 5.56 chamber is fine shooting .223, but the .223 chamber is not built for the pressures developed by 5.56.

 

[Broheim]

My understanding is that the only real difference between them is the pressure, with 5.56 > .223. So a 5.56 chamber is fine shooting .223, but the .223 chamber is not built for the pressures developed by 5.56.

this.

 

[shortylickens]

OP has been schooled. Shorty can leave.

 

[Gillbot]

My understanding is that the only real difference between them is the pressure, with 5.56 > .223. So a 5.56 chamber is fine shooting .223, but the .223 chamber is not built for the pressures developed by 5.56.

that was my understanding as well

Guns stamped 5.56 can safely use 5.56 and .223.

Guns stamped .223 can safely use .223.

Guns stamped 5.56 & .223 can safely use 5.56 & .223.

understood, but when buying online you cant see the markings and you have to rely on the description. some have them id'ed as 556/223 but advise against 556 ammo, hence my confusion.

 

[Pia]

It's not universal truth that you should get ARs in 5.56 though. The best AR gunsmith I know (high level IPSC competitor; builds custom ARs and guarantees 0.5MOA on factory ammo) recommends .223 over 5.56 for better initial accuracy and also for less accuracy lost due to wear over time.

 

[Gillbot]

It's not universal truth that you should get ARs in 5.56 though. The best AR gunsmith I know (high level IPSC competitor; builds custom ARs and guarantees 0.5MOA on factory ammo) recommends .223 over 5.56 for better initial accuracy and also for less accuracy lost due to wear over time.

No, but for better flexibility it's a good idea.

 

[Pia]

No, but for better flexibility it's a good idea.

Is 5.56 ammo cheaper for you than 223?
Other than that, I don't see much benefit in that flexibility in any sort of civilian context.

 

[Vic Vega]

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[Vic Vega]

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[Gillbot]

Is 5.56 ammo cheaper for you than 223?
Other than that, I don't see much benefit in that flexibility in any sort of civilian context.

If my brother already has 556, then yes! I can just swipe his ammo. :biggrin:

 

[Pia]

A single rifle being able to use two different standards of ammunition? No, there's no benefit there at all.

Okay, enlighten me. What is the real world benefit, other than potential cost saving, of being able to use 5.56 ammo in addition to .223 in a civilian rifle?

All the answers I can come up with are only a benefit if your planning and preparation sucks in general, or astronomically unlikely.

 

[Vic Vega]

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[Pia]

Sometimes you have .223 available and sometimes you have 5.56 available.

If you have a .223 rifle and no .223 ammo, it's because you have screwed up. .223 isn't some exotic cartridge; there's no excuse for running out of it any more than there is when you run out of .45ACP for a pistol.

 

[Vic Vega]

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[lxskllr]

If you have a .223 rifle and no .223 ammo, it's because you have screwed up. .223 isn't some exotic cartridge; there's no excuse for running out of it any more than there is when you run out of .45ACP for a pistol.

Well, sometimes people screw up, and flexibility can get you out of a jam. There's no reason to limit yourself unnecessarily.

 

[clamum]

Question posed by the OP has already been answered, and I would think today most modern AR-15s/uppers could handle 223 or 5.56. Is there that many ONLY 223 AR-15s around these days? Just wondering.

As far as the person wondering about the advantages of having a rifle that shoots both, that's kind of obvious and has been answered. It's nice to see some ammo on sale (100 rounds for $30) and just pick it up without wondering if it'll fire in your rifle.

 

[Joseph F]

Yeah, ignore this guy, see my post above.

Did I have to spell out "Take my advice with a grain of salt" for you?

 

[Pia]

Well, sometimes people screw up, and flexibility can get you out of a jam. There's no reason to limit yourself unnecessarily.

"Unnecessarily" implies there's no cost to this flexibility, but as I already said, there is a performance cost.

Whether you are shooting 9mm, .223, 5.56 or .338 Lapua Mag, the only reasonable thing to do is to make sure you have enough ammo in the first place and not rely on immediate availability from external sources (= luck). And that's easy; taking enough ammo with you is no more difficult than putting on a seatbelt if you have made a blanket decision to do it in the first place.

If you aren't screwing up systematically, the actual percentage of times where the option of using an alternative caliber makes the difference between you being armed and unarmed has to be astronomically small.

 

[Specop 007]

I cant recall hearing of any instance of a 223 chambered rifle letting go from shooting 556 ammo. Of course its best not to take chances with 50,000 psi of hot gasses 3 inches from your face too.

556 generally has less choices for bullet selection. .223 has all kinds of hunting and varmint bullets.

Heres a good description.

http://www.thegunzone.com/556v223.html

You can also go with a Wylde chamber which is in between the 2 so you supposedly get the accuracy of the 223 with the pressure limits of 556.

I'd go 556 whenever I have a choice.