Abstract: On November 3, 2010, Employee #1 was proof testing a.357 Magnum hand gun in a device called the Snail. The gun is mounted onto a holder and the door closes and the gun is fired by activating a control. There is no way to see into the machine. When Employee #1 opened the door of the machine, his head, hands, arms, and torso were engulfed in a fireball that came out of the machine. An examination of the machine indicated that the coolant system was not adjusted properly which resulted in ignition of un-combusted powder causing a fire within the machine. A layer of approximately 0.125-in. of burned residue was found in the vent pipe section leading up from the machine. The inspection found that proper checks and maintenance of the equipment were not being done that would have detected a faulty spray pattern. Employee #1 was hospitalized with second and third degree burns to his hands and second degree burns to his face and head.