Guns are typically linked to death, violence and killing. For this reason dreaming about guns is a bad thing as it means you’re having negative thoughts either about yourself or others. It can also be a symbol of ending something, either a relationship, a career, a job or a bad habit. They’re linked to stopping and destroying things.
It can ALSO be linked to accuracy and focus as when you fire a gun you try and aim for a particular target. Maybe it means you want to focus more, or you’re focused on an important event or goal in your life, and you’re worried about whether you’ll achieve it or not.