Machinists perform various duties incident to fabrication, repair or modification of engineer, motor transport, weapons, and accessories. Duties include selection of proper stock and set up of work on lathes, shapes, milling machines, internal and external grinders, drill presses, saws and cylinder, or line-boring machines. Machinists work from sketches, diagrams, blueprints, written specifications, or oral instructions. The control of quality and accuracy is met by the machinists' use of precision measuring devices to include micrometers, vernier gauges, and various other gauges and the subsequent adjustment of machine tool controls. Fabrication of metals is also followed by welding with all standard welding equipment. Maintenance of all shop equipment is performed to ensure that serviceability is sustained. Coordination with other repair shops, reporting of work completion, and the shop administrative functions are requirements to be effected by machinists.

The electro-optical ordnance repairer performs electrooptical maintenance and repair to ground ordnance laser and night vision devices, small missiles systems, and other fire control equipment. Duties also include performing mechanical, mechanical-optical and electrical repairs to include inspecting, troubleshooting and adjusting fire control instruments and systems. The electro-optical ordnance repairer, grades Private through Corporal, also completes basic shop administrative forms and records using technical publications. At the grades of Sergeant and above, the electrooptical ordnance repairer trains, supervises, and performs various duties and tasks incident to the management of an electro-optical ordnance repair shop or facility.

Senior ground ordnance weapons chief supervise the maintenance, repair, and inspection of all small arms weapons and towed artillery howitzers and direct the activities of assigned enlisted personnel in a small arms or towed artillery repair shop or facility. They supervise and manage the administration of small arms or towed artillery maintenance facilities and offices. The senior ground ordnance weapons chief is proficient in the organization, management, operation and conduct of technical inspections of small arms weapons, and towed artillery howitzers, all equipment, and maintenance shops or facilities for maintaining small arms or towed artillery howitzers. The senior ground ordnance weapons chief assists the weapons repair officer in all duties and tasks. They manage command environmental and hazardous waste programs. They supervise and provide oversight of disposal, storage, emergency planning for hazardous waste, and ozone depleting substances.