A professional who tends equipment that imparts decorative bluing or brown-black color, and hard, corrosion resistant surface to gun barrels. Respnsibilities include:

• Mixes solution of acids and metallic salts, according to formula.
• Places barrels on conveyor that passes through coloring tanks, electrical drying, and preheating oven into steam chamber where controlled temperature and humidity promote oxidation.
• Rinses barrels in boiling water and holds them against wire or fiber brush wheel to remove loose rust particles and produce satin finish.
• Repeats rusting and brushing cycle until color of barrel conforms to specified standards.
• Swabs browned barrels with rust-preventing oil, using rag or sponge.