And if it is not?Shoot it quick. I do not know what Armalite's warranty period is. Find out how well the barrel is indexed. For those who do not know what I am talking about, this means how close to absolutely dead centered the rear site aperture is to being EXACTLY dead centered left to right with the rifle shooting exactly dead centered right to left at all applicable ranges.
It MUST be within 4 clicks. Yes it is important. Also I would blacken that barrel by whatever proper means. Enjoy your rifle.
Hundreds of AR15 builds all done the correct way.