MOS 0341 is the United States Marine Corps (USMC) Military Occupational Specialty (MOS) for Mortarman.
The mortarman in the Marine Corps infantry is the mobile support to the rifleman on the front lines. They utilize the M252 81mm mortar and the M224 60mm mortar systems. They are usually located in a 81mm mortar platoon, which in turn is located in the Weapons Company of the Battalion. The mortar platoon is made of up three major components: Forward Observer (FO), Fire Direction Center (FDC), and the gun line.
The mortar platoon is made up of two sections with a total of 68 Marines(67 enlisted, 1 commissioned officer). Each section of the platoon is made up of 4 mortar teams, an FO, and FDC.
Mortar gun lines are typically made up of 4 - 8 mortar systems. Each mortar system has a team of 4 or 5 Marines attached to it. These Gun Teams are broken down as follows:
1.) Gunner - Looks through the sights and aligns them with the aiming post during firing. Remember NFL (Near Post - Far Post - Line)
2.) Assistant Gunner (or A-Gunner for short) - The one who drops the round in the mortar.
3.) Ammo Man - Handles the rounds out of the boxes and packaging. Sets fuses and charges on the rounds before handing them to the A-Gunner for firing. Also keeps a round count to ensure the accountability of all rounds that pass through the mortar.