One Bullet at a Time, is an achievement\trophy in Max Payne 3. It requires the player to get 300 headshots.
The achievement/trophy also reference another famous saying by Max Payne in Max Payne 2's final level: That Old Familiar Feeling whereupon realising that Vladimir Lem's Desert Eagle was with him, Max grabbed the gun and thought: "I was ready to give Vlad his gun back, one bullet at a time."