Reloading 223 for 5.56 chambered ar

[mikey454]

I have a question about loading 223 for a 5.56 chambered ar 15.
I have read in a couple of loading books (hornady, sierra) that you need to use reduced loads when loading 223 for a ar. ( around 3000 fps for 55gr bullets) or you could damage the receiver , bolt , and barrel. i have read that 5.56 is a higher pressure round so is it safe to load 223 to it's max load in a 5.56 chambered gun or do I have to use the reduced loads ?

 

[shredder]

I have a question about loading 223 for a 5.56 chambered ar 15.
I have read in a couple of loading books (hornady, sierra) that you need to use reduced loads when loading 223 for a ar. ( around 3000 fps for 55gr bullets) or you could damage the receiver , bolt , and barrel. i have read that 5.56 is a higher pressure round so is it safe to load 223 to it's max load in a 5.56 chambered gun or do I have to use the reduced loads ?

There's a sticky in the Black and Green Rifles forum that covers this, but the basic answer is YES, you can use max .223 loads in a 5.56 chambered barrel.

It is NOT recommended to use max 5.56 loads in a .223 barrel however.

 

[AlexF]

There are 223/5.56 issues but the most important point to remember is port pressure: the AR, like many semi-autos, works by tapping high pressure gas from the barrel and using its energy to cycle the mechanism.
The main problem with the AR is that it's impossible on all non-piston versions to adjust que quantity/power of the gas used to cycle the rifle.

Short answer, follow Sierra, Hornady and Lyman recommended loads to the letter to avoid overdriving your rifle and breaking it.

Alex