Is there a time or a way you can/should tell someone you have a gun to try and de escalate a situation?

I was thinking of hypothetical situations and was curious about what situation you might want to just tell a person that you’re armed. I was thinking it would always be better to keep it a secret until the need arises but is there some legal benefit perhaps to saying “dear adversary, I do have a gun so please stay calm”What do you think? Thanks. via /r/CCW http://ift.tt/2EjFPJx