I was wondering if you are shot in the lung does it seal its self?

Not likely: Don't believe what you see on TV. When someone is shot in the chest with injury to the lung, it is a life threatening event which can lead to bleeding and death very quickly. Puncture of the lung can lead to tension pneumothorax which can kill in minutes if not treated rapidly with decompression. Not to mention bleeding, or infection of the lung from contamination. Advice: Don't try this at home.