Corporal (CPL), Jeffery S. Fergoson (center), USMC, 1ST Battalion, 3rd Regiment, 3rd Marine Division, instructs a group of Philippine Marines on the proper techniques for cleaning the MK 19 40 mm grenade machine gun during Exercise BALIKATAN 2000. The Philippine Marines all carry 5.56mm M16A1 assault rifles. BALIKATAN 2000 is a joint combined field training exercise held between US and Philippines forces, and is the largest of its kind since 1995