DPMS says 5.56 is OK in .223

[X-Rap]

Has anyone had of seen damage to a 223 from shooting 556 other than throat erosion? Do they use weaker steel in 223 barrels and bolts?
Throat damage will occur with shooting a max load as is known to happen with small cal. large volume calibers not realy dangerous as wasteful.

 

[SHvar]

On the bottom of the barrel in front of the front sight/gas block is a stamped identification letting you know what the barrel and chamber are sized and designed for.
Keep in mind that Sturm Ruger uses cold hammer forged barrels, and chambers them to fire both.
My DPMS is chambered for 5.56x45.
Maybe on their stainless steel .223 barrels it is safe to do, after all stainless steel is alot tougher and more corrosion resistant than standard barrel steel or milspec barrel steel.
Its up to you, you have the info at your disposal.

 

[CoryS]

Ive always heard shoot only 223 in a gun chambered in 223 but 556 will shoot both.

The barrel for my new ar build is chambered in 223 Wylde and will shoot either

Cases are slightly different between a 223 and 556

 

[WardenWolf]

It depends. Some manufacturers actually design their guns for 5.56 but market them as .223 so as not to gain unwanted attention. Unless the manufacturer has confirmed this, however, you should only shoot what the gun is labeled as.

 

[SHvar]

If you reload these rounds you would know that the .223 is a thinner case, can physically hold higher amounts of powder, but can damage from hot loads easily. The 5.56 has a lower wider shoulder, is alot thicker, and is designed to reload with limited powder amounts over and over and over without damage.
The shape, and thickness (therefore less elasticity in the brass) the smaller space, similar load of powder, the 5.56 produces higher pressures, but it depends how you load them both.

 

[heavyshooter]

Why does Ruger use the two synonymously?

Yes, 5.56 in a Mini 14 is fine. It's in the Ruger manual. I think they have a 5.56 chamber anyway.

http://www.ruger-firearms.com/Firear...anuals-RI.html

Quote:
The RUGER®MINI-14®RIFLES are chambered for the .223 Remington
(5.56mm) cartridge. The Mini-14 Rifle is designed to use either standardized U.S. military, or factory loaded sporting .223 (5.56mm) cartridges manufactured in accordance with U.S. industry practice. See “Ammunition Notice” & “Ammunition Warning”, below.

I have heard on more than one occasion that both calibers can be used in a Mini-14. TexasRifleman, thanks for citing a source. This brings up a question that I hope will not change the subject. Why is a Mini-14 capable of safely handling both a .223 Rem. and a 5.56mm? The manual uses the two monikers synonymously. Is it because TexasRifleman's guess holds true; the gun is chambered for 5.56mm and is therefore capable of handling a .223 Remington? Is it basically a .38 Special in a .357 Mag. chamber?