U.S. Army First Lieutenant Bruce Geiger participated in the protracted siege of Khe Sanh during the Vietnam War. For 77 days, the United States 26th Marine Regiment withstood the assault of three North Vietnamese Army divisions. During the famous siege, Geiger commanded A Battery from the 1st Battalion, 44th Artillery (1/44th), a U.S. Army air defense artillery battalion attached to the 3rd Marine Division, the parent unit of the 26th Marine Regiment.
A pair of M42A1 Dusters proved to be valuable components in the defense of the combat base’s airstrip. Positioned at either end of the airstrip with a company of entrenched Marines between them, the Dusters were greatly admired for the heavy firepower furnished by their twin-mounted 40mm Bofors guns. Geiger’s battery was augmented by four truck-mounted .50-calibre machine guns known as Quad-50s.
At the beginning of the siege on January 21, 1968, Geiger confidently told his commanding officer, Marine Corps Colonel David Lownds, that his Dusters and Quad-50s possessed sufficient firepower to repulse a North Vietnamese assault on the northern sector of the combat base should they attempt a human-wave attack. He based this not only on the confidence he had in his equipment, but also on the skill of the crews operating the weapons. Although severely tested over the course of the long siege, Geiger and his crews held their ground and helped to stop several attacks. With a firing rate of 240 rounds per minute, the M42A1s shredded North Vietnamese infantry assaulting the combat base, situated in the northwestern corner of the I Corps Tactical Zone defended by the U.S. Marines.
