| 摘要 |
A casing contains a propelling charge and a bullet or slug (1) with flutes or grooves in its outer surface extending helically around or parallel to the longitudinal axis. Each groove is U-shaped in section and contains spheres (4) of dia. equal to that of the groove cross-section. The spheres are arranged in rows in each of the grooves to support and stabilise the bullet in the firearm barrel during firing. The spheres have dias. equal to the cross-section of their containing groove, being arranged in rows in the grooves to support the bullet. |
