MIL-STD-333B, MILITARY STANDARD: FUZE, PROJECTILE AND ACCESSORY CONTOURS FOR LARGE CALIBER ARMAMENTS (01 MAY 1989)., This standard establishes standard designs for projectile nose fuze threads, fuze contours, and projectile cavities for gun projectiles, 75mm and larger in caliber and mortar projectiles 60mm and larger, to insure physical interchangeability, and that for a given projectile family (artillery bursting oriented artillery cargo oriented, etc.) no special aiming corrections are required when firing any fuze type (PD, MT, Prox, etc.) for which the projectile is intended.