Is a 5.56 chamber stronger than a .223?

[Skeet Mcgee]

I'm considering buying a Ruger American Ranch. It is chambered in 5.56/.223 while the other models of american rifles are chambered in .223 only. Does this mean the Ranch's chamber or action is beefier or somehow stronger to accommodate the higher pressure 5.56 round? I was under the impression that all Ruger American short actions were the same...

Any info is appreciated. Thanks.

 

[bsand]

I think difference is in the throat? The mil case has a shorter throat while civilian has longer?

 

[Skeletor68]

If is reads 5.56 on the Barrel? good to go for both, If it reads .223 on the barrel, ONLY .223

 

[tjhaile]

I think difference is in the throat? The mil case has a shorter throat while civilian has longer?

Yes, but the other way around; the NATO 5.56 chamber has a longer throat than the SAAMI .223 minimum one. That said, actual chamber dimensions will vary and most .223 rifles have longer throats than SAAMI minimum.

A good in-depth discussion can be found here, including pressure test results:
http://www.luckygunner.com/labs/5-56-vs-223/

To summarize, 5.56 ammunition in a .223 chamber is usually OK, with the likely worst case being popped primers tying up the trigger mechanism of semiauto rifles. When in doubt, discontinue use of any ammunition that shows adverse effects.

 

[Skeet Mcgee]

Thanks tjhaile, Great info!