.223 vs 5.56 Is there a difference?

[letusbuyyourcar]

I have a home build AR and my PSA upper reads 5.56 mm on the barrel. I also have maybe 100 rounds of Tula steel case .223 . Is it safe to shoot in my rifle? M first AR WAY back in 95 was a DPMS and it had .223 and 5.56 on the lower.
I have always assumed that 5.56 was just the military metric nomenclature for the round just like .308 is 7.62x51mm. So what's the real deal?

 

[Plinker66]

556 is hotter than 223

308 is hotter than 7.62x51

ODT will correct me if I'm wrong four shore.

 

[medium187mph]

556 is a thicker brass

Think bulk drop from up above 100k rounds to the sandbox... heavy duty brass for war.

Velocity and also a higher pressure on 556 as well over the 223.

223 is a civilian version of the military

If barrel is marked 223... don't shoot 556

If the barrel is marked 556, you can shoot both

 

[BangBang]

If barrel is marked 223... don't shoot 556

If the barrel is marked 556, you can shoot both

THIS

 

[letusbuyyourcar]

556 is a thicker brass

Think bulk drop from up above 100k rounds to the sandbox... heavy duty brass for war.

Velocity and also a higher pressure on 556 as well over the 223.

223 is a civilian version of the military

If barrel is marked 223... don't shoot 556

If the barrel is marked 556, you can shoot both

Cool! So I'm in the safe range running this cheap Tula in my PTAC upper. I was afraid it might have been the other way around with .223 being hotter and intended more for bolt action heavy barrel guns.

 

[medium187mph]

Cool! So I'm in the safe range running this cheap Tula in my PTAC upper. I was afraid it might have been the other way around with .223 being hotter and intended more for bolt action heavy barrel guns.

based on the info you described as saying your barrel is marked 5.56, you can shoot both with no issues.

Tula is a bit dirty and I'd recommend slathering your BCG till it's dripping wet while running it.

I'd rather be shooting Tula then looking at my rifle collecting dust. Go have fun man!

 

[Fatal_Bert]

Cool! So I'm in the safe range running this cheap Tula in my PTAC upper. I was afraid it might have been the other way around with .223 being hotter and intended more for bolt action heavy barrel guns.

No clue what Tula' 223's specs are but they definitely ain't very hot. There's noticably less recoil when compared to 556, and it has the dirty stench of communism when you shoot. But it's cheap and surprisingly accurate for what it is.

 

[Kahrnut]

it has the dirty stench of communism when you shoot.

 

[palmettomoon]

God Jesus not this **** again.

 

[Moondog1]

Yeah there are threads on this with more info. Some bolt guns are marked .223 but in the manual they say 5.56 is fine.