Army enlisted jobs are called "MOSs," or "Military Occupation Secialties."
The Army divides their MOSs into "Fields," of jobs that have similar missions. Below are the MOSs that belong to the Field Artillery Field:
13B - Cannon Crewmember
13C - Tactical Automated Fire Control Systems
13D - Field Artillery Automated Tactical Data Systems Specialist
13E - Cannon Fire Direction Specialist
13F - Fire Support Specialist
13M - Multiple Launch Rocket System Crewmember
13P - Multiple Launch Rocket System Operations/Fire Direction Specialist
13R - Field Artillery Firefinder Radar Operator
13S - Field Artillery Surveyor
13W - Field Artillery Meteorological Crewmember
13Z - Field Artillery Senior Sergeant

