A locking adjustment device for adjusting a setting of an aimed optical device, such as a riflescope, locks at a home or baseline position to provide expedient feedback regarding an adjustment position of the adjustable setting. The device includes a knob mountable for rotation about a rotational axis when the adjustment device is installed on the aimed optical device, where the knob is rotatable about the rotational axis. The device further includes a catch that automatically locks the knob in the home or baseline position and prevents further rotation of the knob until the catch is released. A lock-release mechanism carried by the knob is manually actuatable to disengage the catch and allow the knob to be manually rotated away from the locked position.