CBT STANDARD PROJECTILE

The Conical Boat Tail projectile is the same as the Aberdeen Proving Ground G2 projectile, which was tested there from 1922 to 1925. It is also known as the "Type J" projectile.

It has a conical nose, which is blended to the cylindrical part of the projectile with a radius section. It has a 6 degree boat-tail, half a calibre long.

The program uses second order polynomial drag functions, which were fitted to the drag table data, to calculate the drag for a given velocity. Those functions are as follows:

drag_eqn.gif - 820 Bytes
DRAG FUNCTION TABLE a b c
V < 1100 ft/sec. 4.5672E-5 -8.9627E-3 1.5691
1100 < V < 1200 3.5409E-3 8.4432 -4912
V > 1200 ft/sec. 0 0.189 -104
CBT-projectile