Killer Junior

Killer Junior and Killer Senior are techniques of employing artillery direct fire air bursts, first developed during the Vietnam War. The technique involves a howitzer or gun firing a high explosive (HE) shell fuzed with a mechanical time-super quick (MTSQ) artillery fuse set to function causing an airburst over a target in very close proximity to the gun's position. Set properly, the shell would detonate approximately 10 meters (30 feet) above the ground at ranges of 200 to 1000 meters.

The term Killer Junior was applied to this technique when used with 105mm or 155mm howitzers, and the term Killer Senior applied to its use with the M115 203mm (8-inch) howitzer. The term "Killer" came from the call-sign of the battery which developed the technique. The technique was later perfected by Lieutenant Colonel Robert Dean, commander of the 1st Battalion, 8th Field Artillery Regiment, of the 25th Infantry Division Artillery.

Killers Junior and Senior were developed as alternatives to the Beehive flechette rounds previously used against nearby enemy troops. The advantage of Killer Junior over beehive is that the airburst projects fragments in all directions, and is able to wound enemy crawling or lying in defilade, whereas the flechettes of a Beehive round would simply fly harmlessly over a low target.

Source

 * Major General David Ewing Ott. FIELD ARTILLERY, 1954-1973. Department of the Army. Washington D.C., 1975.