If it was a 40mm that hit the maroon truck it was a shot gun load one with 27 pellets at extreme close range since specs are
For close range fighting two M79 rounds were developed during the Vietnam era. The first was a flechette or Bee Hive round which fired dozens of small darts at once. Later in the war this was replaced by the M576 buckshot round. Containing twenty-seven 00 buckshot, this round was devastating at close ranges. The pellets cast a cone of fire 98 feet (30 m) wide and 98 feet high and travel at 882 feet per second (269 mps). The round has no mechanical-type fuse. This round is olive drab with black markings.