Buckshot is good.<quoted text>
If this guy was trying to force his way into my house in a crowded place like Boston I would not want an AR15. I would prefer my grandfather's double barrel 12 ga. with no. 4 buckshot in one barrel and a slug in the other. Give him the buckshot in the chest first. It would knock him down even if he was wearing body armor. Then stand back a few feet and give him the slug right through the teeth. With an AR15 even my old fashioned 30-30 deer rifle there would be too much chance of the bullet going clean through him, across the street, through the wall of the house next door, and hitting the neighbor.
An Ar is way better than a slug.
You need to bone up on your home defense.