Educate Me 223 or 556

[Jon B]

I have never bought projectiles that were only .223 they have all shown to be .224

[muzzlebrake]

I used to have a Sako Vixen in .223 and I shot both out of it for many years. My Saber Defence AR15 don't care which one I feed it either. All guns are not created equal however. I would say if the round chambers easily and there is no excess resistance closing the bolt and no sticky cases after firing then you will be OK.