An initiator is provided for a munitions device that is intended to strike a target substantially along a trajectory direction and contains an explosive within a case. The initiator includes a sleeve, first and second anvils and an initiation pellet disposed between the anvils. The sleeve is disposed within the case and adjacent to the explosive, and defines an initiator interior aligned substantially parallel to the trajectory direction. The sleeve includes one or more orifices that extend therethrough between the explosive and the interior, the orifices being disposed adjacent to the pellet. The pellet is composed of a reactive material that chemically responds as a non-explosive to kinetic and thermal stimuli. The first anvil is disposed transverse to the interior and forward of the pellet, while the second anvil is disposed within the interior behind of the pellet, wherein the second anvil translates towards the first anvil substantially along the trajectory direction in response to the device striking the target. The pellet discharges particles through the orifices, the particles being directed into the explosive in response to the second anvil translating towards the first anvil. The sleeve can be disposed within the explosive. The reactive material can be a solid or powdered mixture of powdered aluminum and polytetrafluoroethylene or other fluoropolymer, or alternatively a thermite mixture of powdered metal and metal oxide and may include added polytetrafluoroethylene or other fluoropolymer.