Jump to content

What did I buy? AR .223/5.56 question


Guest pusherman

Recommended Posts

Guest pusherman

Sorry if this is a dumb question-

I got a Colt AR15 in about '96. I HAD to have a black rifle, so I got just picked one. I know... not so smart. But at the time that damn assault ban was in place and I couldnt afford a pre-ban rifle.

At the time I assumed 556 and 223 where the same round. I've learned a bit since and I know now thats not the case. Something about bullet length or head space and chamber pressure.

Anyway, stamped on the lower is this -

Match HBAR

CAL. 223

ser CMH 025xxx

But on the end of the barrel is this

C MP 5.56 NATO 1/7 HBAR

So, is this a .223 or a 556? What the heck did I buy?

thanks in advance!

-Jason

Link to comment
  • Replies 18
  • Created
  • Last Reply

Top Posters In This Topic

You have a 1-7" twist barrel. You can shoot the heavier bullets such as the 77 grain bullets and they will stabilize just fine.

You can shoot the lighter bullets also, just the heavier stuff will stabilize. You will pay a premium for the heavier bullet ammo but it is worth it.

Yes, you can fire .223 ammo through it no problem

Link to comment
So, is this a .223 or a 556? What the heck did I buy?
They're essentially the same round. 5.56mm is the NATO designation, and .223 caliber is the for us that don't use the metric system. Edited by mj12
Link to comment
Guest bkelm18
So, is this a .223 or a 556? What the heck did I buy?/QUOTE]Essentially the same round. 5.56mm is the NATO designation, where .223 caliber is the for us that don't use the metric system.

No they are not the same round. 5.56 is loaded to much higher pressure than .223. Same physical shape and size for the most part, but much different pressures.

Link to comment
Guest Todd@CIS
They're essentially the same round. 5.56mm is the NATO designation, and .223 caliber is the for us that don't use the metric system.

If this were true, this thread probably wouldn't exist.

SAAMI considers firing 5.56 in a .223 chamber an unsafe practice.

http://www.saami.org/specifications_and_information/publications/download/SAAMI_ITEM_211-Unsafe_Arms_and_Ammunition_Combinations.pdf

Edited by Todd@CIS
Link to comment

The lower is a part that is for use in rifles sold in the USA. the 5.56 barrel is used for rifles sold world wide. I use 223 in barrel stamped 5.56 but not the reverse. pressure is not the same size is not exact same

Link to comment

EXACT same size, metric vs u.s. meas. anyone who tells you different has no idea. The throat isnt different, its not taller, the case wall thicker, however it doesnt alter the shape of the case. they give you BOTH in iraq for .223 rifles. Pressures are slightly different but not enough to impact ballistics in a major way. All modern rifles (1990+) can handle both. I contracted with a large gun manufacturer, pimped them for information on coffee breaks.

Edited by kesava
Link to comment
Guest manofsteel

my dpms is the same, lower 223, upper is 5.56. i shoot 223 ammo of all types, so far no problems. seams to really like federal best:up:

Link to comment
EXACT same size, metric vs u.s. meas. anyone who tells you different has no idea. The throat isnt different, its not taller, the case wall thicker, however it doesnt alter the shape of the case. they give you BOTH in iraq for .223 rifles. Pressures are slightly different but not enough to impact ballistics in a major way. All modern rifles (1990+) can handle both. I contracted with a large gun manufacturer, pimped them for information on coffee breaks.

I guess you know better than SAAMI and all the major ammunition manufacturers. :tinfoil:

Edited by TN-popo
Link to comment
Are all over the counter ARs sporters, SAAMI chambered? Are some military chambered and head spaced so they can safely fire 5.56?

If the barrel is stamped 5.56 it can shoot both if it is stamped .223 it should only be shot with .223. Most AR's can shoot both. Usually only the hunting oriented or target specific rifles are stamped .223.

Link to comment
I guess you know better than SAAMI and all the major ammunition manufacturers. :poop:

As a reloader and one with an understanding of how SAMMI Derives their data.

Yes....Yes I do. I am somewhat ashamed that the people here at TGO lack the critical thinking to do the same. It is very simple actually, but it is easier to tell people "don't do it" rather than try to explain to people that can't understand. Has to do more with the history of the guns chambering the cartridge rather than the cartridge itself.

Link to comment

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

TRADING POST NOTICE

Before engaging in any transaction of goods or services on TGO, all parties involved must know and follow the local, state and Federal laws regarding those transactions.

TGO makes no claims, guarantees or assurances regarding any such transactions.

THE FINE PRINT

Tennessee Gun Owners (TNGunOwners.com) is the premier Community and Discussion Forum for gun owners, firearm enthusiasts, sportsmen and Second Amendment proponents in the state of Tennessee and surrounding region.

TNGunOwners.com (TGO) is a presentation of Enthusiast Productions. The TGO state flag logo and the TGO tri-hole "icon" logo are trademarks of Tennessee Gun Owners. The TGO logos and all content presented on this site may not be reproduced in any form without express written permission. The opinions expressed on TGO are those of their authors and do not necessarily reflect those of the site's owners or staff.

TNGunOwners.com (TGO) is not a lobbying organization and has no affiliation with any lobbying organizations.  Beware of scammers using the Tennessee Gun Owners name, purporting to be Pro-2A lobbying organizations!

×
×
  • Create New...

Important Information

By using this site, you agree to the following.
Terms of Use | Privacy Policy | Guidelines
 
We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.