A delivery wire assembly for delivery of an occlusive device to a location in a patients vasculature includes a delivery wire conduit having a proximal tubular portion connected to a distal coil portion, and a conduit lumen extending through the proximal tubular portion and the distal coil portion. The delivery wire assembly also includes a core wire disposed in the conduit lumen and having a distal end coupled to an occlusive device. The distal coil portion of the delivery wire assembly includes a plurality of zones and the plurality of zones decrease in stiffness distally along the length of the distal coil portion of the delivery wire assembly.