Abstract: To mitigate groove drag in a kinetic energy projectile, an intumescent maial is inserted in the grooves wherein the material will expand to fill the grooves once the sabot has been discarded. The groove material inhibits aerodynamic recirculation that can occur in the grooves, fills the groove and keeps out freestream gasses. The expanding groove material occupies the space previously filled by the sabot tooth. The groove-filling material expands quickly, because the flight of the projectile is typically on the order of one to two seconds. The groove filling material may also be an elastic material.