Marine Combat Arms Jobs: Infantry, Artillery, Armor

When searchers say they want a Marine combat-arms job, they are usually mixing together three different operational lanes. Some mean infantry. Some mean artillery. Some mean a mounted or amphibious vehicle path but use the word “armor” because that is the closest civilian shorthand they know. These are not the same daily life, the same training pipeline, or the same post-service career bridge.

The faster way to choose well is to split the question into three pieces: foot-mobile combat, fires, and mounted assault support. Getting that distinction right before you walk into a recruiter’s office saves a conversation full of wrong turns.

What combat arms means in Marine structure

The Marine Corps groups combat-arms fields by occupational code. The three fields that cover most of what applicants mean when they say “combat arms” are OccFld 03 Infantry, OccFld 08 Field Artillery, and OccFld 18 Tank/AAV/ACV. A fourth combat-arms-adjacent field, OccFld 13 Armor, was closed when the Marine Corps deactivated its tank battalions in 2021. The current mounted lane now lives inside 18, centered on amphibious and armored vehicle employment.

Each field sits close to combat, but they solve different problems in different ways. An infantry rifleman and a field artillery cannoneer are both in the fight, but one is the point element on foot and the other is supporting the fight through indirect fires from a gun line. Understanding that difference before you decide is more useful than any description of how demanding either path is.

OccFld 03 Infantry: the foot-mobile lane

The 03 Infantry hub is where most combat-arms conversations start, and for good reason. Infantry is the foundation of ground combat. If your mental picture of a Marine job involves patrolling on foot, small-unit tactics, weapons employment at close range, and living in the field, you are describing infantry.

The field runs several distinct specialties that share the same infantry culture but do different things inside it.

0311 Rifleman is the reference point for the whole field. The public Marine infantry page describes 0311 as the base infantry role built around rifle-team work, patrol, and direct-ground combat. Current open public material does not publish a standalone line-score floor for 0311, which distinguishes it from more specialized infantry paths. The training pipeline is the School of Infantry at either Camp Lejeune, North Carolina, or Camp Pendleton, California. The SOI program for infantry Marines runs approximately 59 days and produces a Marine who can operate in a rifle squad as a trained rifleman. The daily work for a 0311 Marine in a rifle battalion covers patrolling, entry operations, vehicle movements, live-fire ranges, combat fitness training, and the full range of small-unit infantry tasks.

0331 Machine Gunner is the direct-fire weapons specialty inside infantry. The published ASVAB requirement is EL, GT, or MM 90. Marines also need to qualify at the WS-B water survival level before completing training. The pipeline goes through the Infantry Marine Course and then the Machine Gunner Course at SOI East or West. A 0331 Marine’s identity is tied to the crew-served weapon: the M240 and similar systems. The work involves sustained direct fire, gun-crew discipline, loading, positioning, and maintaining weapons effectiveness across the full range of infantry operations. Experienced NCOs attend the Advanced Machinegun Course, which covers more complex crew tactical problems and leadership of a machinegun section.

0341 Mortarman is the indirect-fire infantry specialty. The published baseline is CL or GT 90, plus the standard WS-B requirement. Training follows the same Infantry Marine Course first and then the Infantry Mortarman Course at SOI. Mortarmen serve in rifle company weapons platoons and in 81mm mortar platoons at the battalion level. The work mixes the physical demands of infantry field life with the crew-drill precision of mortar employment: calculating data, running the gun correctly, and adjusting fires in coordination with supported elements. NCOs attend the Advanced Mortarman Course. A Mortarman who wants to read the problem rather than pull the lanyard can move toward fire support teams, which sit at the intersection of the infantry world and the artillery field.

0313 Light Armored Reconnaissance Marine sits inside infantry but operates from the Light Armored Vehicle. The current MOS Manual identifies this specialty as skilled in armored reconnaissance, surveillance, and security. The published qualifications include CL 90 or GT 90, normal color vision, a valid driver’s license, WS-B, and height between 65 and 75 inches. Marines first complete the Infantry Marine Course and then the Light Armored Reconnaissance Marine Course at Camp Pendleton. The WS-I water survival qualification is required before completing the LAR course. Senior NCOs complete the Light Armored Reconnaissance Commander Course. The 0313 path blends infantry field craft with vehicle crew work in a way that gives it some of the strongest civilian transfer potential in the 03 field: vehicle discipline, mounted operations, and reporting habits that translate better to civilian employers than a pure foot-combat role.

0321 Reconnaissance Marine is the most selective path inside OccFld 03 and one of the most demanding pipelines in the enlisted Marine Corps. Published qualifications include CL 105 or GT 105, WS-I to enter the Reconnaissance Training Assessment Program, and WS-A to enter Basic Reconnaissance Course. The RTAP physical standards are published: 8 pull-ups minimum, a 3-mile run in 22:30, and a continuous 500-meter swim in 15 minutes. The pipeline runs from MCT through RTAP to BRC. From there, Reconnaissance Marines can pursue advanced qualifications in SERE, low-level static-line parachuting, military freefall, and combatant diving. The follow-on NMOS designations are 0322 (Sniper Qualified), 0323 (Parachute Qualified), 0324 (Combatant Diver Qualified), and 0326 (Parachute and Combatant Diver Qualified).

The ASVAB picture for infantry varies by path. 0311 has no published standalone floor. 0331 and 0341 both require composite scores in the 90-range. 0313 and 0321 require 90 and 105 respectively on CL or GT. For all infantry paths, the GT composite built from VE + AR + MC is the primary line score, with verbal accuracy mattering most because report writing, patrol reporting, and command communication all depend on clear written output.

OccFld 08 Field Artillery: the fires lane

The 08 Field Artillery hub is where the fires conversation starts. Artillery supports the fight from a distance, delivering indirect fires that shape terrain, suppress enemy movement, and enable maneuver. The field’s identity is different from infantry in important ways: the work is crew-centered, procedure-intensive, and built around a system of synchronized fires rather than individual weapon employment.

0811 Field Artillery Cannoneer is the gun-line path. Public Marine artillery guidance describes cannon duties as moving, loading, firing, and maintaining cannon weapons systems. That is the clearest public description of the 0811 daily role. A cannoneer’s workday in a firing battery centers on the gun itself: emplacing it in the firing position, running crew drills until the section can operate smoothly and safely, executing fire missions, and moving to new positions when the battery displaces. Artillery is loud, physically demanding, and heavily dependent on the entire crew moving together. Current open public material does not publish a standalone line-score floor for 0811, but the combat-arms assignment process still applies standard enlistment standards and field-specific physical requirements. The 0811 career comparison points are 0844 Field Artillery Fire Control Marine, which handles firing data and fire-direction work, and 0861 Fire Support Marine, which handles the liaison and coordination side.

0861 Fire Support Marine is the fires-coordination path. Public Marine artillery material describes observation and liaison duties as checking and analyzing combat plans and communicating advice and operating information. The 0861 role puts Marines close to supported maneuver units rather than on the gun line. They help connect the artillery system to the units that need fires: observing, advising, and coordinating so that fires arrive where they need to, when they need to, with the right effect. The daily work demands communication skill, situational awareness, and the ability to stay clear in the head while maneuver elements are under pressure. The civilian transfer story for 0861 is often cleaner than for pure gun-line artillery because the coordination and communication habits the job builds are more legible to civilian employers.

Other paths in the field include 0842 Field Artillery Radar Operator and 0844 Field Artillery Fire Control Marine, which handle the technical and fire-direction sides of the fires problem.

The artillery field as a whole does not provide the cleanest individual ASVAB picture because public composite floors are not consistently published for each specialty. Marines interested in the 08 field should confirm current line-score requirements through their recruiter.

OccFld 18 Tank/AAV/ACV: the mounted lane

The 18 Tank/AAV/ACV hub covers the Marine Corps’ mounted combat-arms lane. When the Corps deactivated its tank battalions, OccFld 18 shifted to center on amphibious vehicle employment. The field now represents the intersection of mounted vehicle operations and amphibious assault capability.

1833 Assault Amphibious Vehicle Crewmember is built around the legacy AAV platform. The work mixes vehicle operations, weapons handling, crew drills, and mechanized movement. Public qualification material for 1833 does not publish a standalone ASVAB floor. The pipeline follows Boot Camp and Marine Combat Training, then vehicle-community schoolhouse instruction tied to amphibious vehicle employment. The daily reality of 1833 work involves maintenance cycles, crew accountability, mounted movement, and vehicle security operations, all within a crew that depends on everyone pulling weight.

1834 Amphibious Combat Vehicle Crew Marine is centered on the current-generation Amphibious Combat Vehicle. The ACV replaced the AAV as the Corps’ primary amphibious assault vehicle. The daily work for a 1834 Marine involves the same crew disciplines as 1833: vehicle operations, weapons employment, maintenance, crew coordination, and mechanized movement in both amphibious and ground environments. Same qualification picture as 1833: no published ASVAB floor, standard accession and vehicle-safety requirements apply.

For Marines who want a mounted combat-arms path but want to stay inside infantry culture, 0313 Light Armored Reconnaissance Marine is the closest adjacent option. It sits inside OccFld 03 but operates from the LAV-25 and provides a different mounted identity than the 18-field vehicle crew paths.

How the three fields compare

What the daily training rhythm looks like

Combat arms daily life has more in common across the three fields than it does with the support community, but the rhythm differs by lane.

Infantry battalions in garrison alternate between range weeks, field exercises, and administrative periods. Range weeks are dense: weapons qualification, combined arms ranges, and live-fire exercises. Field exercises run from two days to several weeks and replicate operational conditions. For 0311 and 0331 Marines, those exercises center on small-unit movements, patrols, and direct-action drills. For 0341 Marines, the exercise work includes setting mortar positions, running crew drills under time pressure, and adjusting fires with supported elements.

Artillery batteries have a different garrison rhythm. Maintenance and crew-level training are the daily foundation. Gun-line crews run drills on emplacement, loading, and operation without actually firing, because the repetitions are what build the section’s reliability. When a live-fire exercise comes, the weeks of dry-fire practice pay off. For 0861 Marines, time in garrison often involves working with maneuver units, attending their planning cycles, and staying current on fires procedures through tabletop exercises and combined arms training events.

Mounted units in OccFld 18 run a rhythm built around vehicle health and crew proficiency. A vehicle out of maintenance is useless in the field, so crewmembers spend real time on maintenance documentation, operator checks, and parts accountability. When units go to the field, the mounted exercises build the crew discipline that makes amphibious operations safe and effective.

Career progression in combat arms

Every combat-arms field runs the standard Marine enlisted promotion track, but the specific NCO responsibilities differ by field.

In infantry, E-5 Sergeants lead squads. For riflemen and machine gunners, the squad leader role is the first position that requires managing other Marines in direct combat leadership. Mortarman NCOs take on section-leadership roles within weapons platoons. The most experienced infantry NCOs serve as platoon sergeants and company gunny sergeants.

In artillery, E-5 Sergeants move toward gun-section leadership in 0811 roles or toward more independent fire-support positions in 0861 work. Senior NCOs often hold battery-level leadership roles, fire-direction chief positions, or training NCO billets.

In the 18 field, vehicle commanders are the career milestone that follows initial crew qualification. Leading a crew in field operations, maintaining vehicle readiness standards, and training junior crewmembers are the main NCO responsibilities.

For Marines interested in the officer side of these fields, 03 Infantry officers, 08 Field Artillery officers, and 18 vehicle officers lead the formations that enlisted Marines operate in.

Reserve considerations

All three fields have reserve presence, but the nature of that presence differs significantly.

Infantry reserve units provide access to infantry training and deployment cycles, but the frequency of field time depends heavily on the unit’s schedule and whether it is aligned with an active-duty deployment cycle. The 59-day SOI pipeline still applies at accession regardless of reserve status.

Reserve artillery presents the same challenge: the guns and the crew are only valuable when they train together at real pace. Reserve batteries that deploy or train alongside active-duty artillery units provide more useful experience than those with limited field time.

Reserve 18-field billets are constrained by platform availability. Vehicle units only exist where vehicles exist. Marines interested in 1833 or 1834 reserve service need to research specific billet locations before assuming the option is available near them.

For 0321 Reconnaissance Marines, reserve access is the most constrained of any combat-arms path. The screening, pipeline, and unit structure all favor active-duty service as the primary route.

Civilian transfer across the three fields

Civilian transfer from combat arms requires honest planning. None of these fields hands you a civilian job title. What they build are the foundations that can be converted into competitive civilian credentials with the right follow-on work.

The clearest transfer picture comes from vehicle-centered and coordination-heavy paths. The 0313 LAR Marine has crew discipline, vehicle operations, reporting, and reconnaissance habits that civilian employers in transportation, fleet operations, and public safety can recognize. The 0861 Fire Support Marine has coordination, communication, and support-integration experience that maps to operations and logistics roles. The 1833 and 1834 crewmembers build vehicle maintenance awareness, crew accountability, and team operations skills.

Pure foot infantry (0311, 0331, 0341) builds some of the most important intangible skills in the Marine Corps: endurance, leadership under real pressure, team trust, and the ability to function in genuinely hard conditions. Those skills transfer, but they transfer through the person rather than through the job title. An employer who has never met an infantry Marine may not know what to do with “0311 Rifleman” on a resume. An employer who has hired veterans before knows exactly what it means.

The education strategy that makes combat arms transfer cleanest is using GI Bill benefits and tuition assistance during service to build a degree or professional credential that civilian employers can evaluate directly. An infantry Marine with a criminal justice degree has a clearer application than the same Marine without it. A vehicle crewmember with a commercial driver’s license opens a different job market than one without. The investment in education does not replace the military experience. It makes it readable to a broader employer pool.

Marines deciding between the three combat-arms lanes should start with 0311 Rifleman vs 0331 Machine Gunner vs 0341 Mortarman for the infantry split, Marine Field Artillery MOS: 0811 vs 0861 for the artillery split, and Best Marine Combat Arms MOS for Civilian Career Transfer for the post-service planning question.

The ASVAB line score requirements for combat arms vary by path. The Marine ASVAB study guide covers how GT, CL, and other composites are calculated and which subtests drive each score.