04815682 is referenced by 16 patents and cites 12 patents.

The invention concerns a fin-stabilized projectile for employment from a rifled barrel and is particularly suitable for automatic cannons having calibers from 12.7 to 70 millimeters. The full rate of spin commensurate with the rifling twist of a specific barrel and the muzzle velocity is imparted to the projectile during launch using a rotating band which is fixed and an integral component of the discarding sabot. Subsequent to exit from the muzzle of the gun the rate of spin of the projectile is decelerated rapidly by aerodynamic damping to avoid potential adverse effects due to Magnus moments. The aerodynamic design of the fins is such that the projectile spin reaches a steady state rate of spin which is at least 50 percent larger than the nutation frequency of the projectile. By means of this spin tuning resonance instability and roll lock-in are avoided over the operational range of the projectile. Launching at full rate of spin also results in large centrifugal forces acting on the components of the sabot which provides for instantaneous and precise sabot separation upon projectile exit from the muzzle. This combined with the highly repeatable and reliable tuning of the projectile spin rate permits excellent projectile accuracy and dispersion characteristics. The invention also includes a discarding sabot design incorporating an integral, fixed rotating band. The design involves the in-place injection molding of the sabot body including a seal with obturator onto the fin-stabilized projectile. The absence of slipping rotating band provides for a rugged sabot configuration which is particularly important for ammunition employed from automatic cannons.

Title
Fin-stabilized subcaliber projectile and method of spin tuning
Application Number
7/75818
Publication Number
4815682
Application Date
July 20, 1987
Publication Date
March 28, 1989
Inventor
Craig L Christenson
All of Santa Barbara
CA, US
Paul J Griffith
All of Santa Barbara
CA, US
Fritz K Feldmann
All of Santa Barbara
CA, US
Agent
Patrick J Walsh
Assignee
Pacific Armatechnica Corporation
CA, US
IPC
F42B 13/16
View Original Source