I thought there would be no one shot kills in this game, but from the wiki
“Unlike all other Weapons in the game, the Barnett is capable of delivering one-hit kills unbuffed when shooting opponents in the head. It is possible for the Barnett to kill a Light Body Type when shot in the chest and Medium Body type when shot in the head.”
Now i am definatly NOT playing light type, and i am debating wether to just Forget about medium aswell. the chest is A big target.