Interior Ballistics
(Page 2/7)

When developing the HDB, an essential goal was to create a profile which would minimize the drawbacks typical of momnobloc style projectiles, such as energy loss by friction, high-peak pressure, barrel fouling. With this in mind, the driving surface of the HDB has been consequently reduced to three or four driving bands respectively with the front cylindrical portion subcalibrated. Apart of that, the bullet additionally features a cone head plus a boat tail to optimize the center of gravity and the built-in precision.

The three or fiur respectively driving bands, in spite of their small width, provide for reliable twist transmission and plus positive gas sealing. The triangular crimping grove (directly behind the first driving band) controlles the seating depth of the projectile and consequently the all-over length of the cartridge (see drawings the beneath).