Systems, devices, and methods for retracting a pull wire from a hypotube can include positioning a pull wire having an engagement bump on its proximal end within a channel of a device and sliding the pull wire proximally through a channel of a device by moving grippers of the device proximally to engage and slide the bump. Subsequent distal movement of the grippers can result in the grippers disengaging the bump without disturbing the position of the pull wire or causing the pull wire to move distally.