I was under the impression that CIP doesn't differentiate between 5.56 and .223, while SAAMI does. If it's made to CIP spec it's likely loaded to 5.56 pressures.
maybe someone can fire a round in a 223 Rem chambered gun.
If it completely self destructs, it is 5.56.
Should only take one round...
Most companies just list 223 as 223, but Barnaul's package says 223 then (5.56), since it is coming from Russia is it really 223 or the slightly longer 5.56?
556 is NOT longer than 223.
maybe someone can fire a round in a 223 Rem chambered gun.
If it completely self destructs, it is 5.56.
Should only take one round...
The difference is in the chambering. The leade is about double the length (freebore) in a 5.56 nato chamber. ALSO, the rifling starts at an angle like a ramp, while with .223 the rifling edge is not ramped, more like a straight up/down edge. Both of these conditions can lead to high pressures if ammo, loaded to slightly higher pressures for 5.56, is loaded into a tighter dimensioned chamber area of a .223
So the 5.56 chamber gives the bullet an unrifled freebore section twice the length of a .223 chamber, which lowers the pressure some, and when the bullet contacts the rifling, the edge of that rifling is ramped to also help keep pressure spikes down. Put 5.56 ammo in a .223 rem chamber, and it has half the freebore, and a 90degree start to the rifling edge. This is where problems can occur if your gun is on the weak side of available actions, or your brass is bad.
maybe someone can fire a round in a 223 Rem chambered gun.
If it completely self destructs, it is 5.56.
Should only take one round...
I've got a suggestion.
Stick your know it all attitude back in your pocket and forget all the garbage about 556 and 223 and just shoot the ammo. There is no reason not to shoot 556 in a 223 chamber. Prior to the internet, millions of people shot hundreds of millions of rounds of 556 in whatever chamber and nobody ever heard of a rifle blowing up as a result.
Consider that a Rem 700 action is the same OD regardless of the cartridge. 223 or 300 Ultra Mag. That means the barrel OD is also the same regardless of cartridge. There is no fear of the action or bbl blowing up when the gigantic Ultra Mag is fired in that rifle. How on earth could anyone think the exact same rifle action is somehow going to explode because the puny little 556 was fired in a 223 chamber?
The entire 223 vs 556 hand wringing is beyond silly and always has been. It is the territory of internet nitpicking.
Awesome cutaway of the 300 Blackout down a .223 pipe!