Patent ID: 8893621

Claim:
A projectile having an ogive section ( 14 ) forward of a bearing surface section ( 16 ) forward of a boattail section ( 18 ); an aft end of the projectile is at an aft end of the boattail section ( 18 ) at a base ( 20 ); the projectile is rotationally symmetrical; a rotationally symmetrical cavity ( 28 ) is positioned inside the projectile and has a depth ( 31 ) bounded at a fore end at a bottom ( 32 ) and at an aft end at the base ( 20 ); the cavity ( 28 ) is open on the aft end of the boattail section ( 18 ) at an aperture ( 40 ) formed in the base ( 20 ); the bearing surface section ( 16 ) has a first diameter; the bottom ( 32 ) as a second diameter; the aperture ( 40 ) has a third diameter; the base ( 20 ) has a fourth diameter; the boattail section ( 18 ) has a first length; the bearing surface section ( 16 ) has a second length; the depth ( 31 ) has a third length; the first diameter is constant from a fore end to an aft end of the bearing surface section ( 16 ); the second diameter that is less than or equal to the third diameter and greater than or equal to about a quarter of the fourth diameter; the third diameter is less than or equal to the fourth diameter; the fourth diameter is less than or equal to fifty-five percent of the first diameter; the third length is between eighty-five percent and one hundred twenty-five percent of the sum of the first length and the second length.