March 28, 2017, by Travis Pike – The United States Marine Corps has a very broad mission. To meet these mission requirements, they have various personnel in different specialties – otherwise known as Military Occupational Specialties or MOS. The main fighting force of the Marine Corps is the infantry.
Infantry carries a 03 designation with two following numbers that break down their specialty. The Marines break down their infantry fighting force into different MOS positions. Infantry Marines fall into a few categories, mainly line and weapons companies.
Line companies are the main fighting force of an infantry battalion.
An infantry battalion is made up of three line companies, and each company consists of three rifle platoons and one weapons platoon.
There is one weapons company per infantry battalion. Traditionally, it is made up of a heavy mortars platoon, an anti-armor platoon, and a heavy machine gun platoon.
It is also divided into Combined Anti-Armor Teams (CAAT). It is made up of mostly 0331’s, 0351’s, and 0352’s.
There are specialty infantry battalions in the Marine Corps.
These are small battalions that usually have only one unit per division. These include Light Armored Reconnaissance Battalion, Division Recon, and Marine Special Operations Battalions.
Here’s a look at the enlisted infantry specialties out there.
Military Occupational Specialty (MOS)
The Marines’ ability to create specialized infantry forces has made them a force to be reckoned with. At the core of every infantry is the rifleman.
They are the core fighting force of the USMC. The majority of the infantry is made up of riflemen. They are the backbone of the infantry and are specialized in both close and medium range combat.
Every MOS in the Marine Corps exists to support the mission of the rifleman. 0311’s serve in line companies primarily.
All infantry Marines are trained as a rifleman at the School Of Infantry. At any time, they can be called to cover a rifleman’s position.
0313 Light Armor Vehicle Crewman
The 0313 community makes up the Light Armored Reconnaissance Battalions found throughout the Marine Corps.
Their mission is both amphibious and land-based. They operate the LAV and its weaponry in the ship to shore, direct action and recon operations.
0331 Machine Gunner
Machine gunners provide automatic, suppressive fire in support of squad level operations. They can be assigned to a Combined Anti-Armor Team (CAAT) or a line company. They are specialized with the M240, the M2, and the MK-19.
Mortarmen provide indirect fire capabilities to an infantry battalion. They serve in weapons battalions or weapons platoons.
Mortarmen in line companies carry the lighter 60mm mortar, and those in weapons companies utilize 81mm heavy mortars.
0351 Infantry Assaultman
Infantry Assaultmen act as the demolition specialist for Marine infantry battalions. They serve in both line and weapons companies.
An Infantry Assaultman provides anti-armor capability through the SMAW rocket launcher. They also act as breachers and demolition specialists with C4, TNT, and other explosives.
0352 Anti-tank Missileman
Anti-tank Missilemen serve in weapons battalions. They are armed with the vehicle or ground mounted TOW (Tube-launched, Optically-tracked, Wire-guided) weapon system and portable Javelin missile launchers.
These are designed to destroy armored vehicles or defeat bunkers and placed positions.
0365 Infantry Squad Leader
One of the newest MOS categories is the Infantry Squad Leader. They are created through the Squad Leader Development Program (SLDP).
It is designed to give Marines in junior leadership positions greater training opportunities and skill building through Sergeants Course and Infantry Small Unit Leader’s course.
0369 – Infantry Unit Leader
Infantry unit leaders are Marines in Staff NCO positions. Staff Sergeant to Master Gunnery Sergeants in the infantry becomes 0369. They are considered infantry experts and can lead any core infantry MOS.
0317 Scout Sniper
The scout sniper MOS has changed over time, but has settled into the 0317 designations. They provide long range reconnaissance, scouting operations, and direct action with surgical precision.
0317 is a designation earned after a Marine passes the Scout Sniper School.
0321, 0323, 0324, and 0326 Recon Man
Recon Men go through different MOS designations based on their qualifications. They are capable of operating from land, air, or sea. They provide long range recon for Marine infantry battalions and provide valuable intel for combat operations.
They are also capable of direct action offensive operations. Recon Man is further divided into normal Recon Marines and Force Recon Marines.
0372 Critical Skills Operator
Another new MOS is the 0372. A critical skills operator is a Marine who is part of MARSOC and has passed the MARSOC training.
These Marines are under SOCOM/JSOC and the premiere Special Operations Unit in the Marine Corps.
About Author: Travis Pike is a former Marine Machine gunner who served with 2nd Bn 2nd Marines for 5 years. He deployed in 2009 to Afghanistan and again in 2011 with the 22nd MEU(SOC) during a record-setting 11 months at sea. He is a writer at Outdoor Empire and you can read his articles here.