Abstract: A highly permeable medium, such as an industrial foam, is utilized within e liquid payload cavity of a spinning artillery projectile to prevent flight instabilities produced by resonant oscillations of the liquid payload prior to the time it attains the spin velocity of the projectile. The highly permeable medium is preferably positioned near an end wall of the substantially cylindrical shell casing and physically acts to create highly viscous forces for causing the liquid in contact therewith to spin up to the projectile's velocity with a speed heretofore unrealized.