ASSESSMENT OF ERFB-BB PROJECTILE

The development of extended range rounds has followed a clearly traceable line of evolution starting with the Rocket-Assisted Projectiles (RAP), passing by Extended Range Sub-Calibre (ERSC) projectiles and Extended Range Sub-Bore (ERSB) projectiles and ending with Extended Range Full Bore projectiles with Boat Tail (ERFB-BT) or Base Bleed (ERFB-BB). The most interesting of all the extended range projectiles developed so far is undoubtedly the very long range ERFB-BB ones, which incorporate the best ballistic features of the other extended range projectiles and achieve the maximum possible payload capacity. In this treatise, a historical review of the development of high-explosive, extended range projectilles is first furnished. The principle of base bleed is then discussed and its use in modern projectiles illustrated via a newly designed ERFB-BB projectile. Necessary calculations of range, accuracy and lethality are performed. In doing so, different base drag reduction ratios are considered. Effects of delayed ignition and slight variations in time of burning of the base bleed charge on range are also stu-died, and maximum range is found to be considerably sensitive to these variations. Possibility of local production of the proposed design is investigated. Anticipated technical difficulties are singled out and possible solutions proposed.