A weapon 1 peripherally discharging projectiles 2a-2n, normally ball bearings, at sustained high rates under centrifugal force has at least one member 11 rotating within a housing, or guide track, 10. Each rotating member 11 has at least one channel, or track, 16 with a radial component within which projectiles 2a-2n received near the center of rotation progress radially outwards until first escaping at 19, and then being ejected at X, under centrifugal force at the periphery of the at least one rotating member 11. A projectile release mechanism controls the timing, locations, and numbers of projectiles released per rotation of the at least one rotating member. This mechanism uses (1) an elongate member 13, substantially positioned along a radius line and within the at least one member 11 with its distal end protruding within the at least one channel 16 and with a proximal end cam follower 13 contacting the interior circumference 181 of (2) a ring cam 18, non-rotating to the housing 10 and movable between positions both coaxial, and displaced, to the rotational axis of the at least one rotating member 11. The elongate arm 13 moves (1) radially outward under centrifugal force of the rotation of the at least one rotating member 11 until its distal end protrudes within the at least one channel 16, therein obstructing passage of projectiles 2a-2n along the channel 16 and any ejection of these projectiles 2a-2n from the periphery of the at least one rotating member 11, until (2) the cam follower 14 of the elongate arm 13 contacts during rotation the cam 181 surface of the ring cam 18, pulling the elongate arm 13 against centrifugal force radially inwards until its distal end ceases to protrude within the channel 16, losing passage of projectiles 2a-2n along the channel 16 for subsequent escape at 19 and for ejection at X.