“The fragmentation grenade was used frequently against suspected areas of heavy jungle growth and on some occasions for the destruction of booby traps around perimeter defenses. Its effect when used as a booby trap is questionable because of the long fuze time. The Japs used our grenades extensively in their night harassing raids against our bivouacs. Rifle grenades were used on some occasions with success against enemy pillboxes.
“In spite of its handicap of sounding like a Jap .25-caliber light machine gun, the Thompson sub-machine gun proved very satisfactory for specialized personnel such as linemen, artillery forward observers, vehicle drivers, and reconnaissance personnel. Its limited range made it especially useful in combat in rear areas.
“The Browning auto rifle gave excellent service. This weapon has high jungle mobility and provides excellent fire power for the short-range targets frequently encountered. It has been used many times to reinforce the final protective lines at night, to establish trail blocks, to cover patrol advances, and to destroy snipers.
“The light machine gun proved very effective in the night security of bivouacs. At other times, it was used to cover the advance of attacking echelons by placing heavy fire in the direction of suspected pillboxes. Since fields of fire and visibility were so limited the effectiveness of such support was questionable.
“We did not use the heavy machine gun to any extent in the attack in the jungle. This was mainly due to its weight and to its heavy ammunition supply requirements. It was used primarily for the defense of beachheads and water passageways, also to some extent in the defense of regimental and battalion command posts.
“The 60mm mortar was not effective against enemy pillboxes, although it unquestionably contributed by its demoralizing effect on the enemy. After we reached the outer taxiways of the airfield, we had excellent visibility from ideally situated OP’s, and the disorganized enemy presented many profitable targets for this weapon. The exceptional accuracy of the weapon made it very valuable in close support, and its use during the assault on the revetments and shell craters at Munda Field and Kokengolo Hill is credited with saving many lives.
“The 81mm mortar proved to be one of the most important single weapons contributing to the success of this offensive. Because of the difficulty of supply only two mortars were taken forward with each heavy-weapons company, the balance of the personnel being used as ammunition carriers. Troops frequently remarked that if given the choice of rations or 81mm mortar ammunition, they would gladly take the latter.
“While the 37mm AT gun is admittedly a weapon of opportunity in jungle warfare, there were two occasions on which it served us handsomely. The Nips had a field piece located where it could interdict our beachhead at Laiana. Scouts located the gun, but our mortar fire couldn’t silence it. We disassembled a 37mm gun and carried it forward under cover of the dense foliage. The gun was then assembled under cover and moved rapidly to a point in the open from where it could command the target. Three accurately aimed rounds destroyed the gun and killed its crew.
“On another occasion we picked up an enemy occupied pillbox about 600 yards from one of our OP’s. The 37mm gun was manhandled to a position on the forward slope in only partial concealment. It placed accurate and intense fire on the pillbox and completely destroyed it.