AR question...

[97F1504RAD]

Man I was geting ready to panic for a second, lol! I am still a n00b to the whole AR game, even though I ma piecing together my first AR right now. I bought a case of .223 55 grain for my AR. The barrel is a Mil Spec 5.56 with a 1/7 RHT, I was looking for 5.56 ammo and .223 always pops up. So I went ahead and ordered the .223 since it is the same that the Mil uses lol! Okay enough of my n00biness!

-Gio

Do not feel bad like i said I have been using both types of ammo interchangeably for around 20 plus years and this was the first time I had ever heard this said.

Google is your friend. It is amazing what you can find on the internet.

My hopes would be that a google search would lead me back here and I would hope since this is a internet forums related to guns some would simply answer the question here.


Also if I am not mistaken his manual for the Colt says something to the effect of magazines for the .223(5.56) caliber ammunition have a capacity of 8 rounds but have a 5 round limiter for hunting. That to me says it shoots both

[x-ring]

Thanks...BUT!

Your Colt upper is chambered in 5.56 anyway, btw. Look at the stamping towards the front of the barrel. That's what tells you the type of ammo for which your barrel is chambered, not the marking on the lower.

The caliber markings on the lower do not create any restrictions on what caliber upper you can put on it. You must always go by what is stamped on the barrel.

Thanks for the info...

With all respect I want to make one comment. And yes it's probably beating a dead horse but many on the forum are new to the shooting sports and if ONE person reads this and says "wow, I didn't know that"...then it's worth the time.

It's chambered in .223 (not 5.56) and it's a match rifle with match tolerances in the chamber (throat). BIG DIFFERENCE 'twixt the two.

This isn't directed specifically at the author of the above post...but I hear/see so many people talk and act as if they're the same round and they're not. Shooting .223 in a 5.56 rifle isn't a problem, but going the other way can be a BIG problem.

The primary difference between .223 Remington and 5.56 x 45 mm is that .223 is loaded to lower pressures and velocities compared to 5.56 mm.

.223 Remington ammunition can be safely fired in a 5.56 mm chambered gun, but the reverse can be an unsafe combination. The additional pressure created by 5.56 mm ammo will frequently cause over-pressure problems such as difficult extraction, flowing brass, or popped primers, but in extreme cases, could damage or destroy the rifle.

Chambers cut to .223 Remington specifications have a shorter leade (throat) area as well as slightly shorter headspace dimensions compared to 5.56 mm "military" chamber specs, which contributes to the pressure issues.

Some have observed up to 20,000 psi higher pressure when shooting a 5.56 round in a rifle chambered for .223. That's the "proof" pressure limit (or close to it) on EVERY round...

...and obviously VERY dangerous. I know there are doubters out there. You may be reading this and telling yourself it ain't no big deal.

You may have gotten away with it for a while, but sooner or later something will fail.

Dead horse is now thoroghly flogged...

[Gio]

^

Good stuff there x-ring, see I learned a lot from a simple yet most made mistake by a lot of people out there. I am glad we have forums like this that have infinite amounts of wisdom and also stupidity so that others can learn either way

-Gio

[97F1504RAD]

Yep I agree.^^^^

So I have another question on this matter. Not to beat a dead horse any longer, but If i am not mistaken the Colt HBAR says .223 on the lower but there are no markings on the barrel. At least none that are visible. So how can we truly find out if it will handle the 5.56 safely. It lists it in the owners manual that the magzines take the 5.56 but no where does it mention not to shoot 5.56 in the firearm. Also are most of the new Ca. Legal AR's being sold in the 5.56 form or the .223 and how can we again be certain if no barrel markings?

[ar15barrels]

It's chambered in .223 (not 5.56) and it's a match rifle with match tolerances in the chamber (throat). BIG DIFFERENCE 'twixt the two.

This isn't directed specifically at the author of the above post...but I hear/see so many people talk and act as if they're the same round and they're not. Shooting .223 in a 5.56 rifle isn't a problem, but going the other way can be a BIG problem.

The primary difference between .223 Remington and 5.56 x 45 mm is that .223 is loaded to lower pressures and velocities compared to 5.56 mm.

So you have a Colt Match HBAR Elite with the 24" stainless barrel?
That's the only one Colt ever did with a 223 chamber.
The rest are 5.56's...

And US Mil-spec 5.56 ammo is loaded to 55,000 PSI, the same as 223 ammo made to SAAMI specs.
Lookup the Mil-specs in TM 43-0001-27
M193 is on page 154 and M855 is on page 170.

Only foreign-made NATO spec 5.56 is going to be higher pressure and the spec on that is 62,000 PSI.

[ar15barrels]

If i am not mistaken the Colt HBAR says .223 on the lower but there are no markings on the barrel.

If there are no markings on the barrel, it's not a colt.

Colt barrels are well marked, usually something like this:



or this:

[Seesm]

In that Colt from all I can find I would say "Just run the .223 to be safe, even though you have run the 5.56 also" I will in any builds I do only do the 5.56 to leave some options open.

So if you swap uppers ever... you can shoot both cuz your new upper will be the 5.56 if you order a 5.56

[97F1504RAD]

If there are no markings on the barrel, it's not a colt.

Colt barrels are well marked, usually something like this:



or this:

Would these markings be under the handguards?

And thanks for posting this info.

[ar15barrels]

Would these markings be under the handguards?

And thanks for posting this info.

Always forward of the front sight base at 12:00.
The marked area is about 3" long so you won't miss it.

Only the oldest military colt barrels, say from 1963 to 1970 are not marked for chambering and those were all 20" A1 barrels.

[97F1504RAD]

Always forward of the front sight base at 12:00.

Only the oldest military colt barrels, say from 1963 to 1970 are not marked for chambering and those were all 20" A1 barrels.

Thank you very much for this info.

[ohsmily]

I guess you don't have a colt upper.

[Omega13device]

Thanks for the info...

With all respect I want to make one comment. And yes it's probably beating a dead horse but many on the forum are new to the shooting sports and if ONE person reads this and says "wow, I didn't know that"...then it's worth the time.

It's chambered in .223 (not 5.56) and it's a match rifle with match tolerances in the chamber (throat). BIG DIFFERENCE 'twixt the two.

Yeah I know the difference between the two calibers, you didn't say it was the Match HBAR Elite so I just assumed you had the Match Target HBAR which is chambered in 5.56 like almost every other Colt EBR. Understandable mixup.

Anyhoo...Regardless of my assumption about YOUR rifle, anyone reading my advice will be in good shape because I said you should always work from the stamp on the barrel.

[97F1504RAD]

Great info in this thread thanks to all who contributed it gave me info that i never knew so if it has helped anyone else then i say good deal.