Firearm & Gun Forum - FireArmsTalk.com > Long Guns > Auto & Semi-Auto Discussion > AR-15 Discussion > .223 vs 5.56

Reply
 
LinkBack Thread Tools Display Modes
Old 10-20-2012, 02:17 PM   #1
Feedback Score: 0 reviews
 
Join Date: Oct 2012
Posts: 7
Liked 1 Times on 1 Posts

Default .223 vs 5.56

I've been told you can shoot a 223 through a 556 but not vise versa any knowledge about this out there?



__________________
truckie98 is offline  
 
Reply With Quote

Join FirearmsTalk.com Today - It's Free!

Are you a firearms enthusiast? Then we hope you will join the community. You will gain access to post, create threads, private message, upload images, join groups and more.

Firearms Talk is owned and operated by fellow firearms enthusiasts. We strive to offer a non-commercial community to learn and share information.

Join FirearmsTalk.com Today! - Click Here


Old 10-20-2012, 02:58 PM   #2
+ TRES VERBO DICTUM +
FTF_SUPPORTER.png
Feedback Score: 0 reviews
 
Vincine's Avatar
 
Join Date: Jun 2011
Location: Adirondack Mts.
Posts: 3,270
Liked 1616 Times on 844 Posts
Likes Given: 1305

Default

I looked into this. There are extensive threads on FTF, which I have contributed to, in the ammo sub-forum I believe, and elsewhere concerning this.

The gist of it is there are small differences in the neck/throat area of the cartridges and corresponding chambers that result in higher pressures in a military 5.56. It was adopted from the civilian 223, but I believe it was changed to provide more energy in order to reliably cycle a dirty automatic weapon under adverse conditions, which a bolt action .223 didn't need to do.

You can shoot a 5.56 out of a .223 firearm but it’s supposed to fatigue the weapon over time and may prove dangerous. I don’t know how many rounds that would take. There are others who load ‘hot’ 223s and use them without issue, so I don’t know whether this is just a theory or a proven fact.

You can shoot a .223 out of a 5.56 without any problem, but may suffer a slight accuracy loss. That said, I would think the difference would be way smaller that one’s own inconsistency in marksmanship.

Rock River Arms’ AR15s, and some others, use a ‘Wylde’ (sp?) Chamber’ which is designed to shoot either without any difference in fatigue or accuracy.

Mossberg makes a bolt action that’s chambered for 5.56. I don’t know of any others. It seems to be rare relatively speaking. You would think there would be more given the flexibility of ammunition a ‘dual' .223/5.56 chambered weapon could use.

And if I wrong I’m sure someone here will let us know straight away.



__________________
"Sometimes I pretend to be normal, but it's boring and I go back to being me."
"You might as well be yourself, people won’t like you anyway."

Last edited by Vincine; 10-20-2012 at 04:23 PM.
Vincine is offline  
 
Reply With Quote
Old 10-20-2012, 03:14 PM   #3
Feedback Score: 0 reviews
 
rhyno13's Avatar
 
Join Date: Jun 2012
Location: A small town inTexas
Posts: 664
Liked 271 Times on 153 Posts
Likes Given: 193

Default

This should answer some of your questions.

http://www.humanevents.com/2011/02/15/223-remington-vs-556-nato-what-you-dont-know-could-hurt-you/

__________________
rhyno13 is offline  
 
Reply With Quote
Old 10-20-2012, 04:31 PM   #4
FTF_SUPPORTER.png
Feedback Score: 0 reviews
 
Join Date: Jul 2007
Location: SW OK
Posts: 4,195
Liked 1978 Times on 1064 Posts
Likes Given: 2950

Default

SAAMI has been spewing this stuff since large quantities of 5.56mm surplus ammo came on the market: Before that SAAMI was silent on the issue. I've been firing 5.56mm M193 US ammo in my .223 rifles since 1968. The fifteen or so .223 rifles i have owned since 1968 have fired at least 200,000-250,000 rounds of 5.56mm ammo with no ill effects. If you don't feel comfortable firing 5.56mm ammo in your .223 then don't do it.

Until recently no one had tested this SAAMI claim. That has now changed:

http://www.luckygunner.com/labs/5-56-vs-223/

There are at least one dozen different .223/5.56mm chambers. Here are some of them. See detailed reamer dimensions:

http://ar15barrels.com/tech.shtml

__________________

Last edited by alsaqr; 10-20-2012 at 04:38 PM.
alsaqr is offline  
 
Reply With Quote
Old 10-20-2012, 04:41 PM   #5
Feedback Score: 0 reviews
 
AgentTikki's Avatar
 
Join Date: Oct 2010
Location: City of Lost Angels, Kommifornia
Posts: 3,444
Liked 335 Times on 264 Posts
Likes Given: 51

Default

read this, all the answers you seek and much much more

http://www.firearmstalk.com/forums/f20/ar15-primer-beginners-guide-59600/

__________________
Assumption is the mother of all ****ups.
Know what you know, Know what you don't know. -Paul Pedzolt
"Jack of all trades, master of none, though oftentimes better than master of one" -Mynshul
AgentTikki is offline  
 
Reply With Quote
Old 10-20-2012, 05:21 PM   #6
+ TRES VERBO DICTUM +
FTF_SUPPORTER.png
Feedback Score: 0 reviews
 
Vincine's Avatar
 
Join Date: Jun 2011
Location: Adirondack Mts.
Posts: 3,270
Liked 1616 Times on 844 Posts
Likes Given: 1305

Default

Quote:
Originally Posted by alsaqr View Post
SAAMI has been spewing this stuff since large quantities of 5.56mm surplus ammo came on the market: . . . . (etc)
Wow! Science!

It always seemed to me that tests with consistent pressure measurement methodology would have been easy enough to perform. I couldn’t understand why it was never done, until now. It also seemed to me that what differences in pressure there are, should have been easily accommodated by the safety tolerances engineered into the product. I was surprised that firing a 5.56 in a .223 barrel was considered a risk. I would’ve expected the .223 barrels, or any firearm for that matter, would be much more robust and be able to handle pressures two or three times the stress.

Thanks for this.


__________________
"Sometimes I pretend to be normal, but it's boring and I go back to being me."
"You might as well be yourself, people won’t like you anyway."
Vincine is offline  
 
Reply With Quote
Reply

Thread Tools
Display Modes