"If the shooter is facing you, quickly reach up and take hold of the barrel, and then aim it away from your body. The move should be as clean and economical as possible."
sounds easy enough.
"Then, punch him in the face or the throat as hard as you can. Hit him on the nose, jab your fingers into his eyes, or strike him with the heel of your open palm. Then use your free hand to grab the nonbusiness end of the gun. With two hands on the gun, you can knee the attacker in the groin. A better idea might be to twist your hands like they are revving a motorcycle engine. The weapon will pivot and break the gunman's finger inside the trigger guard."
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