5.56 or .223?

[beerup949]

Does using 5.56 or .223 in my AR make a difference in accuracy?

Thanks

[kermit315]

some say yes, some say not enough to notice in an AR platform, but remember this: if you have a .223, you can only shoot .223 out of it. If you have a 5.56, you can shoot either.

Dont make a mistake and get a .223 barrel, then try to shoot 5.56 out of it, it is bad for the gun and possibly dangerous to you.

[reidnez]

Firing .223 out of a 5.56 barrel may cause a very slight reduction in accuracy because the leade (distance before the bullet engages rifling) is longer in the 5.56 specifications. As Kermit mentioned it's usually not major enough to make a big difference, in most AR platforms. If you have a super-accurized AR and you're firing match-grade .223 vs match-grade 5.56, you might notice it.

You don't want to shoot 5.56 in a .223 barrel because the 5.56 pressure rating is much higher.

[beerup949]

I have an AR that says 5.56 on the lower so thats good it shoots both. I have also only shot 5.56 so far through it but I wanted to try some .223 now. So no real big diff. though huh?

[offroadking]

I have an AR that says 5.56 on the lower so thats good it shoots both. I have also only shot 5.56 so far through it but I wanted to try some .223 now. So no real big diff. though huh?

you have to make sure the barrel says 5.56, not the lower

[kermit315]

it doesnt matter what the lower says, it matters what is stamped on the barrel. If the barrel says 5.56, you are ok, if it says .223, only fire .223 in it.

[Norccer]

BCM is stamped 5.56, correct?

[1lostinspace]

If you use .223 instead of 5.56mm the world will come to it's miserable end.

[God Bless The Mauser]

I've fired .223 and 5.56 out of my bull barrel AR with a 5.56 chamber and they shoot the same. I can get 1MOA with TAP and V-Max and thats with the stock trigger, if my match trigger would ever come I could get even better groups. I don't know why but it really hates PPU match, can only get 2-3MOA which sucks because that's what most of my ammo is.

[beerup949]

The barrel also says 5.56. I have a matching upper and lower. OC Armory I think drives to AZ and picks up their stuff and brings it back to Cali. So I bought this AR complete.

[kermit315]

sounds good, you should be GTG. Have fun blasting away.

[beerup949]

Cool.