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 Colt marked both .223 (lower) and 5.56 (barrel), wth?
jason934  [Team Member]
2/4/2012 7:02:03 PM EST
I've had my HBAR for quite some time now and have shot it hundreds of times with both 556 and 223 ammo without problems. I had never noticed until now that the receiver is marked as .223 though the barrel shows 5.56. Is it common for Colt to do this? Makes me wonder if it was mismatched at some point before I bought it new





thanks
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TexasBob  [Member]
2/4/2012 7:29:31 PM EST
That's common. My 6520s say 223 on the lower and 5.56 on the barrel. Some lowers say "Multi". The barrel is what tells the tale.
TadJackson  [Member]
2/4/2012 7:36:07 PM EST
Originally Posted By jason934:
I've had my HBAR for quite some time now and have shot it hundreds of times with both 556 and 223 ammo without problems. I had never noticed until now that the receiver is marked as .223 though the barrel shows 5.56. Is it common for Colt to do this? Makes me wonder if it was mismatched at some point before I bought it new

http://i281.photobucket.com/albums/kk218/ironbyron_2008/664c2f7b.jpg
http://i281.photobucket.com/albums/kk218/ironbyron_2008/2403555d.jpg


thanks




my colt is the same way. 5.56 on the barrel and .223 on the reciever
50-140  [Team Member]
2/4/2012 7:36:32 PM EST
My Colt 6721 has the same markings, nothing unusual.
jason934  [Team Member]
2/4/2012 7:39:21 PM EST
Thanks, part of the Colt mystique I guess... Of all companies, you'd think Colt would know there's a difference in the 2 cals, specially for a Match labelled rifle.
George_in_Wis  [Team Member]
2/5/2012 5:57:34 PM EST
Colt civilian receivers have always been marked .223. I suspect it has to do with the fact that nobody knew what "5.56" was when the rifle was introduced nearly fifty years ago, and it's only been relatively recently that 5.56-labeled ammo has been available.

Gentleman4561  [Team Member]
2/5/2012 6:02:03 PM EST
this
Originally Posted By George_in_Wis:
Colt civilian receivers have always been marked .223. I suspect it has to do with the fact that nobody knew what "5.56" was when the rifle was introduced nearly fifty years ago, and it's only been relatively recently that 5.56-labeled ammo has been available.



Augee  [Team Member]
2/5/2012 6:05:14 PM EST
When in doubt, trust the barrel markings.

You can slap any upper on any lower regardless of what's marked.

The chamber is in the barrel.

~Augee
George_in_Wis  [Team Member]
2/5/2012 6:19:53 PM EST
Thanks for the clarification Augee.

My post above is not intended in any way to imply that you should only shoot .223 in your Colt rifle. Even though the receivers say .223, nearly all Colt rifles are chambered for 5.56. Stamping on the barrel determines which ammo the rifle's chambered for.

jason934  [Team Member]
2/5/2012 6:22:08 PM EST
Originally Posted By George_in_Wis:
Thanks for the clarification Augee.

My post above is not intended in any way to imply that you should only shoot .223 in your Colt rifle. Even though the receivers say .223, nearly all Colt rifles are chambered for 5.56. Stamping on the barrel determines which ammo the rifle's chambered for.



while we're on this topic, anyone have a similar barrel? What ammo have you found for best overall performance?
Skillshot  [Team Member]
2/5/2012 7:53:19 PM EST

Originally Posted By jason934:
Thanks, part of the Colt mystique I guess... Of all companies, you'd think Colt would know there's a difference in the 2 cals, specially for a Match labelled rifle.

I'm glad they at least mark their lowers with a caliber. Otherwise how are you supposed to know what uppers you can put on it?
GHPorter  [Team Member]
2/6/2012 1:42:30 AM EST
The lower has absolutely nothing to do with what the UPPER is chambered for. The barrel says what it's chambered for, but ATF regs (at least used to require a caliber marking on the "firearm," which is the lower. So Colt generically marks their civilian-market lowers with ".223" but to my knowledge they don't even make barrels with .223 Remington chambers.
GHPorter  [Team Member]
2/6/2012 1:44:20 AM EST
Originally Posted By Skillshot:

Originally Posted By jason934:
Thanks, part of the Colt mystique I guess... Of all companies, you'd think Colt would know there's a difference in the 2 cals, specially for a Match labelled rifle.

I'm glad they at least mark their lowers with a caliber. Otherwise how are you supposed to know what uppers you can put on it?
You can put ANY caliber upper (that will work with the lower's mag well size) on a lower. The caliber marking on a lower indicates the "original configuration" of the firearm, just like a car would have the factory specs for the engine and drive train; in both cases you can upgrade to something different, as long as it all works together.

Augee  [Team Member]
2/6/2012 4:06:04 AM EST
Originally Posted By GHPorter:
The lower has absolutely nothing to do with what the UPPER is chambered for. The barrel says what it's chambered for, but ATF regs (at least used to require a caliber marking on the "firearm," which is the lower. So Colt generically marks their civilian-market lowers with ".223" but to my knowledge they don't even make barrels with .223 Remington chambers.


They do, but they're marked prominently not only on the barrel, but on the upper if it's factory assembled:



For ammunition, each barrel has its likes and dislikes, but I see no reason not to give 77gr. SMKs a try out of it to start with. The 1/7 barrel will be able to handle just about any projectile length, it just depends on what load you prefer.

~Augee
1saxman  [Member]
2/6/2012 4:36:32 AM EST
The original M16s and Colt magazines were marked .223. I guess they just kept using that on the lower, maybe to make it look more 'Sporter' after the military adapted the 5.56mm specification. Or, just to indicate the 'generic' caliber of the assembled rifle to satisfy their perception of legal requirements, or maybe it's just a Colt thing. Any way you cut it, it's basically just another facet of 'Coltness' to talk about. Many of us still refer to the caliber as '.223', and even on 5.56 ammo boxes you may find .223, 5.56 or both. I think the differences in the specs for the two versions are not significant enough that I would not shoot 5.56 in a .223 chamber in an emergency.
George_in_Wis  [Team Member]
2/6/2012 7:37:06 AM EST
Originally Posted By Augee:
Originally Posted By GHPorter:
The lower has absolutely nothing to do with what the UPPER is chambered for. The barrel says what it's chambered for, but ATF regs (at least used to require a caliber marking on the "firearm," which is the lower. So Colt generically marks their civilian-market lowers with ".223" but to my knowledge they don't even make barrels with .223 Remington chambers.


They do, but they're marked prominently not only on the barrel, but on the upper if it's factory assembled:

http://i901.photobucket.com/albums/ac216/Rockyriver1234/AR15%20Stuff/DSCN1068.jpg

For ammunition, each barrel has its likes and dislikes, but I see no reason not to give 77gr. SMKs a try out of it to start with. The 1/7 barrel will be able to handle just about any projectile length, it just depends on what load you prefer.

~Augee


The barrels on the "223 Colt" marked uppers are the same as those used on the unmarked uppers. Colt only used the 223 Colt marking on the uppers marketed as conversion kits during the period they were also selling conversion 7.62X39 uppers (which were marked "7.62X39"), in order to identify and distinguish them from each other.

I believe the only rifles Colt has built with a .223 Rem chamber are some custom shop rifles (Custom Elite?) with custom barrels. I used to own a 6724 upper when they were first available. I read in some gun rag that the 6724 barrel was made for Colt by Remington; it may have had a 223 chambered barrel, but honestly don't remember.
Augee  [Team Member]
2/6/2012 8:03:42 AM EST
Originally Posted By George_in_Wis:
Originally Posted By Augee:
Originally Posted By GHPorter:
The lower has absolutely nothing to do with what the UPPER is chambered for. The barrel says what it's chambered for, but ATF regs (at least used to require a caliber marking on the "firearm," which is the lower. So Colt generically marks their civilian-market lowers with ".223" but to my knowledge they don't even make barrels with .223 Remington chambers.


They do, but they're marked prominently not only on the barrel, but on the upper if it's factory assembled:

http://i901.photobucket.com/albums/ac216/Rockyriver1234/AR15%20Stuff/DSCN1068.jpg

For ammunition, each barrel has its likes and dislikes, but I see no reason not to give 77gr. SMKs a try out of it to start with. The 1/7 barrel will be able to handle just about any projectile length, it just depends on what load you prefer.

~Augee


The barrels on the "223 Colt" marked uppers are the same as those used on the unmarked uppers. Colt only used the 223 Colt marking on the uppers marketed as conversion kits during the period they were also selling conversion 7.62X39 uppers (which were marked "7.62X39"), in order to identify and distinguish them from each other.

I believe the only rifles Colt has built with a .223 Rem chamber are some custom shop rifles (Custom Elite?) with custom barrels. I used to own a 6724 upper when they were first available. I read in some gun rag that the 6724 barrel was made for Colt by Remington; it may have had a 223 chambered barrel, but honestly don't remember.


You may be right about the markings, though I could've sworn that I've handled a Colt standard 20" HBAR with a .223 marking. I might be confusing it with .222.

The Custom Shop rifle was the TE6700 with a 1/8 .223 bull barrel.

~Augee
George_in_Wis  [Team Member]
2/6/2012 8:44:49 AM EST
Thanks.

I remember the rifle and the specs–– just couldn't remember the model number.
Skillshot  [Team Member]
2/6/2012 9:08:08 AM EST

Originally Posted By GHPorter:
Originally Posted By Skillshot:

Originally Posted By jason934:
Thanks, part of the Colt mystique I guess... Of all companies, you'd think Colt would know there's a difference in the 2 cals, specially for a Match labelled rifle.

I'm glad they at least mark their lowers with a caliber. Otherwise how are you supposed to know what uppers you can put on it?
You can put ANY caliber upper (that will work with the lower's mag well size) on a lower. The caliber marking on a lower indicates the "original configuration" of the firearm, just like a car would have the factory specs for the engine and drive train; in both cases you can upgrade to something different, as long as it all works together.


Yeah but it's going to void your warranty.
Frens  [Team Member]
2/6/2012 10:02:35 AM EST
Originally Posted By jason934:

while we're on this topic, anyone have a similar barrel? What ammo have you found for best overall performance?


both my colt barrels like 69gr bullets
underdogII  [Member]
2/6/2012 10:34:12 AM EST
My two month old Colt SP6920 Sporter has no caliber markings on the lower, only 5.56 on barrel?
Unicorn  [Industry Partner]
2/6/2012 4:35:38 PM EST
At one point thee was no such thing as "5.56."
There are people who don't know the difference and don't know that .223 can be fired in either chamber. This makes it easier for them to find ammo in wherever they are, instead of searching forever for 5.56 because they think that's all they can shoot.

Posted Via AR15.Com Mobile
1saxman  [Member]
2/6/2012 4:48:56 PM EST
Originally Posted By underdogII:
My two month old Colt SP6920 Sporter has no caliber markings on the lower, only 5.56 on barrel?


They 're making changes on the recent guns.

Unicorn  [Industry Partner]
2/8/2012 6:11:29 PM EST
Colt does not recognize a difference. Their chambers (and the military) have never changed. They were called .223 until NATO nations adopted it in 1980 or so. NATO did not create the caliber, they just started calling it their metric name.
It was originally designed as a military cartridge, with the longer leade and specific pressure.
Some company wanted a tighter match type chamber and this was the problem. It's been changed from the original .223 / 5.56 chamber designed. If the makers doing this were to have done itcorrectly they would have given it a totally different name.
Most commercial ammo is underloaded to avoid risk with these out of spec, improperly named chambers.
In reality NATO is using the Colt chamber.

Posted Via AR15.Com Mobile
TM109  [Member]
2/11/2012 10:15:02 AM EST
Originally Posted By Unicorn:
Colt does not recognize a difference. Their chambers (and the military) have never changed. They were called .223 until NATO nations adopted it in 1980 or so. NATO did not create the caliber, they just started calling it their metric name.
It was originally designed as a military cartridge, with the longer leade and specific pressure.
Some company wanted a tighter match type chamber and this was the problem. It's been changed from the original .223 / 5.56 chamber designed. If the makers doing this were to have done itcorrectly they would have given it a totally different name.
Most commercial ammo is underloaded to avoid risk with these out of spec, improperly named chambers.
In reality NATO is using the Colt chamber.

Posted Via AR15.Com Mobile


This. Bore diameter is .219 in which equals 5.56mm.
Dragynn  [Member]
2/11/2012 10:40:32 AM EST
Originally Posted By Augee:

You may be right about the markings, though I could've sworn that I've handled a Colt standard 20" HBAR with a .223 marking.

~Augee


You have.

My circa-1992 R6601 HBAR has the .223-marked lower with a 5.56 marked barrel.

CJan_NH  [Team Member]
2/11/2012 10:43:36 AM EST
Originally Posted By jason934:
Originally Posted By George_in_Wis:
Thanks for the clarification Augee.

My post above is not intended in any way to imply that you should only shoot .223 in your Colt rifle. Even though the receivers say .223, nearly all Colt rifles are chambered for 5.56. Stamping on the barrel determines which ammo the rifle's chambered for.



while we're on this topic, anyone have a similar barrel? What ammo have you found for best overall performance?

Currently I own two Colt 6601 HBARs. 69gr SMK, 75gr Hornady TAP, and 77gr all perform very well with that particular barrel. Even the lighter Nosler Ballistic Tip varmint rounds work well too, despite the fast 1:7 twist



Posted Via AR15.Com Mobile
George_in_Wis  [Team Member]
2/11/2012 11:16:24 AM EST
Originally Posted By Dragynn:
Originally Posted By Augee:

You may be right about the markings, though I could've sworn that I've handled a Colt standard 20" HBAR with a .223 marking.

~Augee


You have.

My circa-1992 R6601 HBAR has the .223-marked lower with a 5.56 marked barrel.



I believe Augee was referring to a .223 barrel marking. 5.56-marked barrels are the norm.

Patriot556  [Team Member]
4/7/2012 11:13:43 AM EST
I always go with the markings on the barrel.

My "Clinton" Colt Match HBar reads 223 on the lower and 556 Nato 1/7 on the barrel.
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