Beehive ( ammunition ) Beehive is an anti - personnel round fired from an artillery gun . The round is packed with metal flechette s which are ejected from the shell during flight by a mechanical time fuze . It is so called because of the ' buzzing ' sound the darts make when flying through the air . It is intended for use in direct fire against enemy troops . The first round actually termed " beehive " was first fired in combat in 1966 and was thereafter used extensively in the Vietnam War , though the later development of the Killer Junior air burst technique provided an alternative to beehive in some situations . The primary beehive round for this purpose was the M546 anti - personnel tracer ( APERS - T ) shell which projected 8000 flechettes and was direct fired from a near horizontally leveled 105 mm howitzer . Beehive rounds were also created for recoilless anti - tank weapons including 90 mm , 106 mm , Ontoses and M48 tanks . Subsequently it was reported that the USSR had developed similar rounds for 122 mm and 152 mm artillery for use in indirect fire . Beehive rounds became less popular in the United States following Vietnam , with low - angle airburst techniques such as Killer Junior supplanting the use of beehive . Sanshiki ( anti - aircraft ) . The term " Beehive " may also refer to Sanshiki , San - Shiki or sanshikidan ( lit . " type 3 " ) ammunition , a combined shrapnel and incendiary round for anti - aircraft use , used by the Imperial Japanese Navy in World War II . The shell was designed for several gun calibers , including the 18 - inch ( 460 mm ) gun s of the " Yamato " - class battleships . The 460 mm ( 18 in ) round weighed 2 , 998 lb and was filled with 900 incendiary tubes and 600 steel stays . The round was equipped with a delay fuze set before firing , that detonated the shell at the set altitude ; on explosion , the steel stays and the incendiary tubes were ejected in a 20 - degree cone forward , with the shell fragments from the explosion itself further increasing the amount of debris . The incendiary tubes ignited about a half - second later and burned for five seconds with 16 - foot long flames . Each of the incendiary tubes was a 90 mm long , 25 mm diameter hollow steel cylinder , filled with rubber thermite ( phosphorus , vulcanized rubber , natural rubber , stearic acid , sulphur and barium nitrate ) and ignited through holes on both sides . The rounds were similar to conventional shells , except for their wood - filled ogive and several layers of assembled fragments . The blast of the main guns turned out to disrupt the fire of the smaller antiaircraft guns , so the 460 mm rounds were not successful . The copper drive bands of the rounds were poorly machined , and constant rapid fire was damaging to the gun rifling . The 406 mm ( 16 in ) round contained 1 , 200 incendiary tubes and on explosion burst into 2 , 527 fragments . By contrast a 460 mm round burst into 2 , 846 fragments . The 203 mm ( 8 in ) round weighed 125 . 86 kg and contained 255 incendiary tubes and a 2 kg burst charge in its base . It used the 91 Shiki delay fuze . Its maximum altitude was 10 , 000 m and it was reached after 55 seconds of flight . The burst charge scattered the fragments in a 12 degree cone . The maximum effective distance from the shell burst was about 1 , 000 meters , where the fragments reached dispersion diameter of 100 meters . A 127 mm ( 5 in ) round contained 66 incendiary tubes and had a 10 degree dispersion angle with dispersion diameter of 54 meters .