[Outlaw Star]

I have searched and can confirm that I believe I know the difference between the two rounds: 5.56 is NATO standard with higher pressures and velocities than the .223 SAAMI civilian round. Also, .223 can be fired in .223 and 5.56 but 5.56 can only be fired in 5.56.

My question is more on nomenclature or identification. My rifle clearly says to use .223 remington and not 5.56 however all of the ammo I see online and in the store say ".223 REM (5.56x45mm)". How can I be sure that I do not accidentally pick up 5.56 (inteded for ARs) for use in my savage model 10? I have looked on google but since .223/5.56 is usually associated with ARs I am having trouble finding a definitive answer.

For example, gun-deals.com only lists .223 and not 5.56 similarly to the-armory.com.

Upon closer inspection of the Brown Bear ammo (.223) website, they have this:
"Brown Bear is loaded to exacting standards normally reserved for military specification ammo." However their website doesn't seem to list .223/5.56 under their Brown bear mil-spec category. .223 Rem is stamped on the brown bear casing but I am simply unsure weather to interpret them as having higher loading standards or if they are loading rounds intended for military or AR applications.
Have I been firing the wrong ammunition down my barrel and should I be worried about erosion due to improper velocities/pressures? I fire both Brown bear and PMC bronze which claims "This ammunition was constructed to Mil-Spec and loaded to SAAMI specs allowing it to be fired in either .223 or 5.56." leading me to believe that it is .223 that can be fired in my rifle safely as well as 5.56 ARs.

 

[Baldy]

Here is a link to a site that will tell you all about it.
http://www.6mmbr.com/223Rem.html

 

[oldbadger]

Here is a link to a site that will tell you all about it.
223 Rem + 223 AI Cartridge Guide

I looked at this site and noted it was from 2009. I did post on this topic with a question about using .223 brass reloaded to 5.56 data. I saved the site you linked.

 

[BerettaAPX9mm]

Don't forget that the .223 Wylde fires both safely as well.

 

[martinsean624]

.223 is civilian market, 5.56 is military. As with anything military is is built to allow more slop and lower tolerances to facilitate functioning on a battlefield in the mud, sand, etc. .223 is tighter and because of which you get a more consistent experience. As stated above .223 wylde is the best of both worlds

 

[Russ D]

Would anybody please share with us a story of when they fired 5.56 thru a 223 rifle, and it caused a problem?

We'll wait . . .

 

[Stamps6]

I for one am shocked at this new information.

 

[Square target]

Would anybody please share with us a story of when they fired 5.56 thru a 223 rifle, and it caused a problem?

We'll wait . . .

I've done it quite a few times and each and every time it was a problem when i ran out of ammo.

 

[Coalcracker]

So when i find .556 ammo laying on the ground. It won't hurt to shoot it in my Savage .223? I down load them by 3 grains of powder currently.

 

[Zhills]

So Coal, how much live ammo do you find laying on the ground? or are you talking about 5.56 brass? which if that's the case if you load it to .223 specs, it works just fine. I like to segregate my cases by type and head stamp.

 

[Coalcracker]

I find a lot of 22lr on the ground. I might find 1 live 223/556 out of 50. I find live 9mm pretty often too.

 

[Square target]

So when i find .556 ammo laying on the ground. It won't hurt to shoot it in my Savage .223? I down load them by 3 grains of powder currently.

I never even look at the head stamps. I just clean, process and load them to .223 specs regardless of which case they are.

 

[Coalcracker]

I sort by H.S for my one customer. Who is a competition shooter. With the slow down in brass recently. I ended up loading what i had set aside for him. I load the .223 on my lee turret press. I have a new turret coming for my Lyman brass smith press. It has no turret flex like the lee does. So im wodering if the flex vs no flex effects accuracy for rifle.If not i'll keep rolling them out on the lee.

 

[empiregladysNY24]

my goto is the .223 wylde

 

[Stamps6]

my goto is the .223 wylde

And what ammo do you use? There is actually no such round. It simply means that you can shoot .223 or 5.56 with no issues or over pressure. Reloading to .223 specs is the safest and you’ll never notice any difference.