A professional who tends machine that loads small arms cartridges with powder and inserts bullets. Responsibilities include:

• Inserts bullets in holes of dial feed plate and observes cartridge case feed lines for tipped and inverted cases.
• Notifies loading-unit tool-setter of machine malfunction.
• Measures samples of loaded cartridges for conformance to specifications, using go-not-go gauges.
• May replenish powder supply.