A professional who sets up and operates metalworking machines to cut, shape, and fit parts to fabricate prototypes or modify existing models of small arms for use as production models, analyzing specifications and determining procedures according to knowledge of metal machining and layout. Respnsibilities include:

• Lays out design of new parts on steel stock according to blueprints and scale drawings.
• Determines fixtures, tooling, and sequence of machining operations to fabricate parts.
• Sets up and operates metalworking machines to cut, shape, and fit parts.
• Files, grinds, burnishes, and polishes parts to obtain smooth movements.
• Verifies conformance of machined workpiece to specifications, using sine bars, verniers, calipers, and micrometers.
• Records data for use of tool maker and tool designer in establishing operating standards and machinery procedures.
• May test fire prototypic arms.