5.56 & .223

Tonkaboi72

Tonkaboi72

Member
EE Expired
Rating - 100%
1   0   0
Location
B.C.
I just wanted to make sure one thing.

Is it correct that in theory .223 and 5.56 are interchangeable.

However, one should and can fire .223 with 5.56 rifle but not the other way around.

So if I wanted to shoot both, I should buy 5.56 rifle.
Am I making any sense??


Thanks.
 
Tonkaboi72 said:
I just wanted to make sure one thing.

Is it correct that in theory .223 and 5.56 are interchangeable.

However, one should and can fire .223 with 5.56 rifle but not the other way around.

So if I wanted to shoot both, I should buy 5.56 rifle.
Am I making any sense??


Thanks.
Click to expand...

The US is not issuing export licenses for anything marked 5.56mm, and have clarified that they are enforcing this. If the rifles you are looking at are American export, and they're new, talk to your dealer about particular specs/capabilities, there may be more to the situation than meets the eye.
 
It likely already does shoot 556 safely, but for coversation sake, a 223 spec chamber adjusted to 556 spec is a 556 spec chamber.

Over the next few months all new legally exported US guns sold in Canada that may have been previously marked/marketed as 556 will be marked/marketed as 223.

In some cases much time and expense has gone into ensuring that this is a complete non-issue (both in perception and in actuality) for end users.
 
Last edited:
dangertree said:
It likely already does shoot 556 safely, but for coversation sake, a 223 spec chamber adjusted to 556 spec is a 556 spec chamber.

Over the next few months all new legally exported US guns sold in Canada that may have been previously marked/marketed as 556 will be marked/marketed as 223.

In some cases much time and expense has gone into ensuring that this is a complete non-issue (both in perception and in actuality) for end users.
Click to expand...
What a friggen joke.
 
I had this confusion because some times I would see such marking or description as ".223/5.56" or ".223 and 5.56" and ".223" or "5.56".

If they are interchangeable, why would there be so many differnt types of marking?

I heard that 5.56 was derived from .222 not from .223 so there IS very tiny difference in measurement. Also since 5.56 is mostly military issued ammo, it will produce higher pressure when fired. Combination of such, could prove to be very costly.


From what I read from here, I guess it is safe to assume now that all new .223 rifles are adjusted to discharge 5.56 safely??:confused:
 
Aside from the longer leade and slightly bigger headspace of the 556 chamber, outside case diamensions are exactly the same. The case wall of a NATO 556 round is thicker than that of a 223. The smaller case capacity generates higher pressure and not wise to shoot in REM 223 chambers. If handloading, I'd be careful using NATO 556 load data in 223 cases. :)

Because NATO 556 rounds generate higher pressures, the longer leade not only aids the bullet gain velocity before it hits the lands, but the slightly greater headspace gives the brass a bit of room to expand and togeather help reduce overall pressure.
 
Last edited:
see below.........
" Before the Internet came along a guy could mix and match 223/556 and 308/762 (nato) with nary a problem......"
Click to expand...

Before the internet, we didn't know how many blew their face off because of it. ;)

Regards.
 
Last edited:
The original poster's final assumption is great... Unless you are talking from the perspective of shooting something like a Mini-14.

Is it safe to say that here in Canada, it is a non issue because we don't have milspec ammo or firearms that would make it a problem?
 
223 556

Been shootin both in military 556 rifles and 223 commercial rifles interchangeably for 40 years - never had a problem :weird:
 
You must log in or register to reply here.
Back
Top Bottom