SOI: School of Infantry
All graduates of Marine Corps recruit training attend the School of Infantry (SOI). At SOI, they will train with one of two training battalions, either MCT or ITB. All non-infantry Marines attend training at Marine Combat Training Battalion (MCT), while infantry Marines (all Marines with a Military Occupational Specialty (MOS) of 03xx) attend training at Infantry Training Battalion (ITB).
MCT: Marine Combat Training
All non-infantry Marines, upon completion of recruit training, will undergo Marine Combat Training (MCT). MCT consists of 29 days of battle skills training that enables Marines, regardless of MOS, to operate in a combat environment.
ITB: Infantry Training Battalion
Infantry Training Battalion's (ITB) mission is to train and qualify infantry Marines in the Military Occupational Specialty (MOS) of 0311 Riflemen, 0331 Machinegunner, 0341 Mortarman, 0351 Assaultman, 0352 Anti-tank Guided Missileman, or 0313 Light Armored Vehicle (LAV) Crewman. ITB consists of a 59 day 0311 course that must be completed by all infantry Marines regardless of specific MOS. After training day 21, the "split" will occur. This means each Marine will be separated by their specific MOS and conduct training specific to that MOS.
Reviewed by CH
Marines training to be machine gunners break up their ammunition into different lengths before starting a sequence of fire on range 218A in the 53-area of Camp Pendleton, California.
—USMC photo by Cpl. Orrin G. Farmer