Actually it can't kill 1 person with 1 pull of the trigger actually unless you get a headshot. Soooo....
Oh it certainly kill in one burst, the other two guys were maybe partially injured but yeah the gun is beast
It does 33 damage and shoots 3 bullets per burst.
He was trying to tell you that the only way you were able to kill a guy in one burst is because at least one of those bullets in that burst landed on the head, which multiplied the damage enough to allow it to kill in a single burst.