Is the Sheiva with the high caliber attachment a one-hit headshot kill?

The Sheiva is normally a two hit kill, but I noticed that it could have the High Caliber attachment on it, which makes each headshot do more damage than usual. Since I'm pretty sure the Sheiva is already a two headshot hit kill, does the High Caliber attachment make it one, like a sniper?


When the high caliber attachment is used on the shieva it does give you a one shot headshot, and if you are in hardcore mode I believe you can have a one shot headshot without the shieva.