I have been wondering about that. If you were to three tap him center mass, the vest would stop the rounds, but could he continue the fight?
Good tactical body armor will stop a rifle round. My CHL carry sidearm wouldn’t even sting him if he was wearing that type of ballistic protection.
Were he wearing a standard DOJ IIIA rated concealable vest...... Yes it would hurt like the dickens an derail his plan A for sure.
My opinion.... Stay Safe !